Sunday, October 18, 2020

Fedora 32 : About positive and negative lookahead with Bash commands.

Today I will talk about something more complex in Linux commands called: positive and negative lookahead.
This solution can be found in several programming languages including Bash
The lookahead process is part of regular expressions.
The lookahead process looks ahead in the string and sees if it matches the given pattern, but then disregard it and move on.
It is very useful when we want to go through the strings.
The lookahead process can be both positive and negative depending on the purpose.
Negative lookahead is indispensable if you want to match something not followed by something else and looks like this:
q(?!s).
The string is the question q is analyzed and if it does not match and is not followed by s returns the result.
The positive lookahead it works the same way only now it is parsed if it corresponds to s.
The positive lookahead looks like this:
q(?=s)
Let's look at a simple example of detecting the PAE option for the processor.
We can use this command but we will find a lot of information ...
[root@desk mythcat]# cat /proc/cpuinfo
processor	: 0
vendor_id	: GenuineIntel
cpu family	: 6
model		: 58
model name	: Intel(R) Celeron(R) CPU G1620 @ 2.70GHz
stepping	: 9
...
In some cases, the resulting information can be taken using pipe and grep but they will be increasingly fragmented.
I will use the same command cpuinfo and we will look for the pae information in the flags.
All CPU flags can be found here.
Let's prove with internal lookahead to find the pae flag.
[root@desk mythcat]# cat /proc/cpuinfo | grep -oP '(?='pae')...' 
pae
pae
This result gives me additional information, namely that there are two cores.
Do you have a question?

Saturday, October 17, 2020

Fedora 32 : Visual Code and C# on Fedora distro.

Today I will show you how to use Visual Code with C#.
sudo rpm --import https://packages.microsoft.com/keys/microsoft.asc
sudo sh -c 'echo -e "[code]\nname=Visual Studio Code\nbaseurl=https://packages.microsoft.com/yumrepos/
vscode\nenabled=1\ngpgcheck=1\ngpgkey=https://packages.microsoft.com/keys/microsoft.asc" > 
/etc/yum.repos.d/vscode.repo'
Then use dnf to check and install this editor.
#dnf check-update
#dnf install code
Use Extensions button or Ctrl+Shift+X keys to open in the left side area and intall the C# extension from Microsoft by pressing the Install button, see:

Created a folder named CSharpProjects and using the linux terminal execute the following command:
[mythcat@desk CSharpProjects]$ dotnet new mvc -au None -o aspnetapp
The template "ASP.NET Core Web App (Model-View-Controller)" was created successfully.
This template contains technologies from parties other than Microsoft, 
see https://aka.ms/aspnetcore/3.1-third-party-notices for details.

Processing post-creation actions...
Running 'dotnet restore' on aspnetapp/aspnetapp.csproj...
  Restore completed in 112.76 ms for /home/mythcat/CSharpProjects/aspnetapp/aspnetapp.csproj.

Restore succeeded.

[mythcat@desk CSharpProjects]$ cd aspnetapp/
[mythcat@desk aspnetapp]$ code .
This command will open the Visual Code. At this point, in the aspnetapp folder is an ASP.NET project open in Visual Code. You can run this project with command:
[mythcat@desk aspnetapp]$ dotnet run
warn: Microsoft.AspNetCore.DataProtection.KeyManagement.XmlKeyManager[35]
      No XML encryptor configured. Key {4c284989-9a5d-4ea7-89e2-a383828fd7ab} may be persisted 
      to storage in unencrypted form.
info: Microsoft.Hosting.Lifetime[0]
      Now listening on: https://localhost:5001
info: Microsoft.Hosting.Lifetime[0]
      Now listening on: http://localhost:5000
info: Microsoft.Hosting.Lifetime[0]
      Application started. Press Ctrl+C to shut down.
info: Microsoft.Hosting.Lifetime[0]
      Hosting environment: Development
info: Microsoft.Hosting.Lifetime[0]
      Content root path: /home/mythcat/CSharpProjects/aspnetapp
You can open the https://localhost:5001/ and see the default Welcome page from ASP.NET.

Saturday, October 3, 2020

Fedora 32 : Create games with Phaser Editor 2D.

Today I install Phaser Editor 2D on Fedora 32, you can download it from the official website. I create an account and I download the archive for Linux. After unarchive I used very simple:
[mythcat@desk ~]$ cd PhaserEditor2D/
[mythcat@desk PhaserEditor2D]$ ls
editor  PhaserEditor2D  README.TXT  templates
[mythcat@desk PhaserEditor2D]$ ./PhaserEditor2D 
Phaser Editor 2D - v3.7.1

=> Running in Free mode (only 70 files per project allowed)
=> Purchase a license: https://gum.co/phasereditor

2020/10/03 16:17:51 Loading workspace at /home/mythcat/PhaserEditor2D_Projects
2020/10/03 16:17:51 Listening at http://127.0.0.1:1959/editor

Play IDE online : https://play.phasereditor2d.com/
Documentation   : https://help.phasereditor2d.com/v3
File bugs/ideas : https://github.com/PhaserEditor2D/PhaserEditor2D-v3/
Keep in contact : https://twitter.com/PhaserEditor2D

=> Open the web browser at http://127.0.0.1:1959/editor

2020/10/03 16:17:52 No updates available.
Phaser Editor 2D is a commercial IDE to develop video-games. It is delivered as an offline product and users can run it for free (with certain limitations) or can purchase a license key to unlock all features. Phaser Editor 2D version 3, the latest, is a complete new software based on web technologies. So we created Play Phaser Editor 2D, a small service to allow Phaser Editor 2D license owners, to run the editor and create small projects in the cloud. However, in the future, we will provide a different cloud service with options for storage, collaboration, publishing, integration with other services and payment. These are the Play Phaser Editor 2D available plans: Free Plan and Premium Plan About Free Plan: Running the FREE PLAN 0B/50MB of storage is used 59 days before expiration date The Premium Plan comes with these options:
  • One Year License - 30$ Valid for one year after the purchase. Phaser Editor 2D Team email support. Write to developers@phasereditor2d.com. The option to refund in the first month after the purchase.
  • Two Years License - 45$ Valid for two years after the purchase. Phaser Editor 2D Team email support. Write to developers@phasereditor2d.com. The option to refund in the first month after the purchase.
  • Lifetime License - 75$ Never expires. Phaser Editor 2D Team email support. Write to developers@phasereditor2d.com. The option to refund in the first month after the purchase.
  • Two Years Team License - 125$ 5 developers allowed. Valid for two years. Phaser Editor 2D Team email support. Write to developers@phasereditor2d.com. The option to refund in the first month after the purchase.
This is a video tutorial from official youtube channel:

Friday, October 2, 2020

Fedora 32 : Can be better? part 015.

In the evening I can spend my time with Fedora 32.

In the last few days I studied GTK # a bit.

I thought it would be useful for Linux users and those who use the language of the FASM assembler to have an editor.

Tonight I created this simple project this simple project named fasm_editor.

The objectives of this project are:

  • creating a functional editor;
  • implementation of running and compilation requirements;
  • settings specific to the Linux operating system;

I believe that this way Fedora Linux can be improved and become better.

Wednesday, September 30, 2020

Fedora 32 : Can be better? part 014.

The GTK documentation for C # is not very up to date, I tried to use a button to change a label and I failed first time. The Fedora team could improve this to develop the development side. Here's what I've managed to do so far with GTK.

I fixed the source code with this, but I would have preferred a better method:

my_Button.Clicked += delegate {
my_Label.Text = "Use delegate!";
};

Mono is a free and open source implementation of the .NET Framework.

The most popular build tool for Mono is NAnt.

NUnit is very useful for test driven development.

[root@desk mythcat]# dnf install mono-devel
Last metadata expiration check: 0:15:26 ago on Wed 30 Sep 2020 09:04:30 PM EEST.
Package mono-devel-6.6.0-8.fc32.x86_64 is already installed.
Dependencies resolved.
Nothing to do.
Complete!
[root@desk mythcat]# dnf install nant
...
Installed:
  log4net-2.0.8-10.fc32.x86_64            nant-1:0.92-25.fc32.x86_64           
  nunit2-2.6.4-24.fc32.x86_64            

Complete!
[root@desk mythcat]# dnf install nunit nunit-gui
Last metadata expiration check: 0:02:09 ago on Wed 30 Sep 2020 09:27:18 PM EEST.
No match for argument: nunit-gui
Error: Unable to find a match: nunit-gui

Installing MonoDevelop:

[root@desk mythcat]# dnf install monodevelop
...
Installed:
  ORBit2-2.14.19-23.fc32.x86_64                                                 
  gamin-0.1.10-36.fc32.x86_64                                                   
  gnome-desktop-sharp-2.26.0-36.fc31.x86_64                                     
  gnome-sharp-2.24.2-25.fc32.x86_64                                             
  gnome-vfs2-2.24.4-30.fc32.x86_64                                              
  gnome-vfs2-common-2.24.4-30.fc32.noarch                                       
  gtk-sharp2-2.12.45-11.fc32.x86_64                                             
  gtk-sharp2-devel-2.12.45-11.fc32.x86_64                                       
  gtksourceview2-2.11.2-31.fc32.x86_64                                          
  libIDL-0.8.14-21.fc32.x86_64                                                  
  libbonobo-2.32.1-18.fc32.x86_64                                               
  libbonoboui-2.24.5-18.fc32.x86_64                                             
  libgnome-2.32.1-20.fc32.x86_64                                                
  libgnome-keyring-3.12.0-19.fc32.x86_64                                        
  libgnomecanvas-2.30.3-19.fc32.x86_64                                          
  libgnomeui-2.24.5-21.fc32.x86_64                                              
  mono-addins-1.1-13.fc32.x86_64                                                
  monodevelop-5.10.0-17.fc32.x86_64                                             
  vte-0.28.2-31.fc32.x86_64                                                     

Complete!

Install the .NET Core. This is a general-purpose, modular, cross-platform and open-source development Platform.

[root@desk mythcat]# dnf copr enable @dotnet-sig/dotnet
Enabling a Copr repository. Please note that this repository is not part
of the main distribution, and quality may vary.
...
Do you really want to enable copr.fedorainfracloud.org/@dotnet-sig/dotnet? [y/N]: y
Repository successfully enabled.
[root@desk mythcat]# dnf install dotnet
Copr repo for dotnet owned by @dotnet-sig             5.4 kB/s | 3.3 kB     00:00    
Package dotnet-3.1.108-1.fc32.x86_64 is already installed.
Dependencies resolved.
Nothing to do.
Complete! 

Let's start with a GTK project using the MonoDevelop I.D.E.

[mythcat@desk ProjectsCSharp]$ monodevelop 
I use a new solution from .NET with GTK# 2.0 Project template. The default source code is this:
using System;
using Gtk;

namespace MonoDevelopGTK_001
{
	class MainClass
	{
		public static void Main (string[] args)
		{
			Application.Init ();
			MainWindow win = new MainWindow ();
			win.Show ();
			Application.Run ();
		}
	}
}
The result is an simple window form. For a complex form with entry ,label and one button, you can see the next example:
using System;
using Gtk;

namespace MonoDevelopGTK_001
{
	
	class MainClass
	{
		public static void Main (string[] args)
		{
			// define here Entry and Button 
			Entry name;
			Button my_Button;

			Application.Init ();
			MainWindow win = new MainWindow ();
			// change the size of window
			win.SetDefaultSize (640, 480);
			// this will close application
			win.DeleteEvent += new DeleteEventHandler (Window_Delete);

			// use of VBox or HBox
			VBox global_vbox = new VBox();
			win.Add(global_vbox);
			name = new Entry();
			global_vbox.PackStart(name, false, false, 0);
			win.Add(name);

			VBox label_vbox = new VBox();
			global_vbox.Add (label_vbox);
			//Define here a label and put some text in it.
			Label my_Label = new Label();
			my_Label.Text = "Hello World!";
			label_vbox.PackStart(my_Label, false, false, 0);
			//Add the label to the form
			win.Add(my_Label);

			VBox button_vbox = new VBox();
			global_vbox.Add (button_vbox);
			my_Button = new Button("Ok!");
			my_Button.Clicked += OnButtonClicked;
			button_vbox.PackStart(my_Button, false, false, 0);
			win.Add(my_Button);
			// ShowAll is used to see all labels, buttons
			win.ShowAll();
			//win.Show ();
			Application.Run ();

		}

		public static void OnButtonClicked (object obj, EventArgs args)
		{
			//Label my_Label = obj as Gtk.Label;
			Console.WriteLine ("Button Clicked !");

		}

		static void Window_Delete (object obj, DeleteEventArgs args)
		{
			Application.Quit ();
			args.RetVal = true;
		}
	}
}

Tuesday, September 29, 2020

Fedora 32 : Can be better? part 013.

I would say that I always have a problem with accessing the knowledge base related to errors, errors and configurations in Linux and Fedora distro.

I think it would be very necessary to have as up-to-date documentation as possible in the Fedora distribution system and possibly a database based on questions and answers.

That makes me think of the pilots' manuals ... where all the possible problems are listed.

It would be useful for anyone and especially saves users' memory.

In the age of artificial intelligence, a flow chart for each possible problem generated by Xorg, Network, services that indicate the areas of interaction and possibly the basic checks that a user should make, possible settings depending on the problem or the desired change would be a fantastic map for both a beginner and an advanced user.

After doing some SELinux configurations, my browser did not want to access the internet.

Until the deactivation, the number of SELinux alerts increased dramatically.

The written SELinux policies were not exactly correct.

Obviously I tried to fix the problem by disabling SELinux.

The ping utility sent and received packets to the internet, my browser does not connect to it.

Sometimes a symbolic link or incorrect setting can block your internet access.

I think the problem was generated when disabling SELinux by restarting and shutting down a useful service.

ln -s /run/systemd/resolve/resolv.conf /etc/resolv.conf
Although attention was paid to the possibility of incorrect SELinux settings, a simple check and a restart of the systemd-resolved.service service solved the problem.
[root@desk mythcat]# systemctl status systemd-resolved.service 
● systemd-resolved.service - Network Name Resolution
     Loaded: loaded (/usr/lib/systemd/system/systemd-resolved.service; disabled
     Active: inactive (dead)
       Docs: man:systemd-resolved.service(8)
[root@desk mythcat]# systemctl start systemd-resolved.service 
[root@desk mythcat]# systemctl status systemd-resolved.service
● systemd-resolved.service - Network Name Resolution
     Loaded: loaded (/usr/lib/systemd/system/systemd-resolved.service; disabled
     Active: active (running) since Tue 2020-09-29 22:25:32 EEST; 8s ago

Now I've fixed it.

Sunday, September 27, 2020

Fedora 32 : Can be better? part 012.

Pidgin is a chat program which lets you log into accounts on multiple chat networks simultaneously. Pidgin can be install on multiple operating systems and platforms. Pidgin is compatible with the following chat networks out of the box: I.R.C., Jabber/XMPP, Bonjour, Gadu-Gadu, IRC, Novell GroupWise Messenger, Lotus Sametime, SILC, SIMPLE, and Zephyr. Can it be better? The only problems a user in need of help may have are in the command line environment. Obviously, in this case, this application cannot be used. I would suggest building a terminal application like WeeChat dedicated to Fedora users and including I.R.C channels. Now, let's install this application.
[root@desk mythcat]# dnf install pidgin.x86_64
Last metadata expiration check: 0:45:32 ago on Sun 27 Sep 2020 04:21:51 PM EEST.
Dependencies resolved.
==============================================================================================
 Package                     Architecture    Version                   Repository        Size
==============================================================================================
Installing:
 pidgin                      x86_64          2.13.0-18.fc32            updates          1.4 M
Installing dependencies:
 cyrus-sasl-md5              x86_64          2.1.27-4.fc32             fedora            41 k
 cyrus-sasl-scram            x86_64          2.1.27-4.fc32             fedora            27 k
 farstream02                 x86_64          0.2.9-1.fc32              fedora           239 k
 gtkspell                    x86_64          2.0.16-20.fc32            fedora            43 k
 libgadu                     x86_64          1.12.2-10.fc32            fedora           110 k
 libnice-gstreamer1          x86_64          0.1.17-2.fc32             updates           20 k
 libpurple                   x86_64          2.13.0-18.fc32            updates          5.2 M
 meanwhile                   x86_64          1.1.0-28.fc32             fedora           106 k

Transaction Summary
==============================================================================================
Install  9 Packages

Total download size: 7.2 M
Installed size: 31 M
Is this ok [y/N]: y
Downloading Packages:
...
Complete!

Tuesday, September 22, 2020

Fedora 32 : Testing the Bookworm software.

The current version of Bookworm (v1.1.2) supports eBooks in the following file formats: EPUB, PDF, MOBI, FB2, CBR, CBZ.

First, I install this software with dnf tool:

[root@desk mythcat]# dnf install bookworm.x86_64 
...
Installed:
  bookworm-1.1.3-0.1.20200414git.c7c3643.fc32.x86_64                                          

Complete!

I tested with some old EPUB and PDF files and I'm not very happy with formatting text on the page.

HI tested with some old EPUB and PDF files and I'm not very happy with the formatting for certain texts on the page, like source code in programming.

Bookworm does one thing and does it well for this simple reader.

You can help this project on GitHub.

Monday, September 21, 2020

Fedora 32 : Can be better? part 011.

Four days ago, the well-known Gnome environment came with a new release.

I guess it will be implemented in Fedora distro soon. 

Sunday, September 20, 2020

Fedora 32 : Can be better? part 010.

In this tutorial I will show you how can easy learn with a simple example to have a better Fedora distro with SELinux. 

SELinux uses a policy store to keep track of its loaded policy modules and related settings. 

You can see my active policy store name is MLS.

[root@desk mythcat]# sestatus | grep Loaded
Loaded policy name:             mls

I want to create policy in the most easy way to denny memory. 

I can use many way to do that or find it on SELinux. 

If you want to deny user domains applications to map a memory region as both executable and writable you can use deny_execmem

This is dangerous and the executable should be reported in bugzilla and is is enabled by default. 

You must turn on the deny_execmem boolean.

setsebool -P deny_execmem 1
Let's use it:
[root@desk mythcat]# setsebool -P deny_execmem 1
[root@desk mythcat]# ausearch -c 'Web Content' --raw | audit2allow -M my-WebContent
******************** IMPORTANT ***********************
To make this policy package active, execute:

semodule -i my-WebContent.pp

[root@desk mythcat]# semodule -X 300 -i my-WebContent.pp
Let's see if this SELinux is currently loaded:
[root@desk mythcat]# semodule -l | grep Web
my-WebContent

Tuesday, September 15, 2020

Fedora 32 : Can be better? part 008.

The Fedora development is not very active in the last programming language.
The main reason is the build new packages and put on the repository.
I think this can be improved with a good tool to solve all dependencies and link all into a good package.
Today I tested the new Python version 3.5.10 released on September 5th, 2020.
I download an unzip the archive and I use these commands to build this python version
[mythcat@desk ~]$ cd Python-3.5.10/
[mythcat@desk Python-3.5.10]$ ./configure
checking build system type... x86_64-pc-linux-gnu
checking host system type... x86_64-pc-linux-gnu
checking for python3.5... no
checking for python3... python3
checking for --enable-universalsdk... no
...
The next command is make:
[mythcat@desk Python-3.5.10]$ make
gcc -pthread -c -Wno-unused-result -Wsign-compare -DNDEBUG -g -fwrapv -O3 -Wall -Wstrict-prototypes
   -Werror=declaration-after-statement   -I. -I./Include    -DPy_BUILD_CORE -o Programs/python.o 
./Programs/python.c
...
# On Darwin, always use the python version of the script, the shell
# version doesn't use the compiler customizations that are provided
# in python (_osx_support.py).
if test `uname -s` = Darwin; then \
 cp python-config.py python-config; \
fi
Then I used make test.
[mythcat@desk Python-3.5.10]$ make test
running build
running build_ext
INFO: Can't locate Tcl/Tk libs and/or headers

Python build finished successfully!
...
For the last part I used this command:
[mythcat@desk Python-3.5.10]$ sudo make install
...
The result of this is ...
[mythcat@desk Python-3.5.10]$ ls
aclocal.m4     config.sub    Include          Mac              Modules  platform        python            README
build          configure     install-sh       Makefile         Objects  Programs        Python            setup.py
config.guess   configure.ac  Lib              Makefile.pre     Parser   pybuilddir.txt  python-config     Tools
config.log     Doc           libpython3.5m.a  Makefile.pre.in  PC       pyconfig.h      python-config.py
config.status  Grammar       LICENSE          Misc             PCbuild  pyconfig.h.in   python-gdb.py
[mythcat@desk Python-3.5.10]$ ./python 
Python 3.5.10 (default, Sep  6 2020, 22:32:07) 
[GCC 10.2.1 20200723 (Red Hat 10.2.1-1)] on linux
Type "help", "copyright", "credits" or "license" for more information.
...

Fedora 32 : Can be better? part 009.

The Fedora distro will be better if the development team will come with useful, accurate, and up-to-date information. A very simple example is C and C ++ programming and more precisely how to build programs and packages. Let's take a simple example of creating interfaces with GTK. Let's take a simple example of creating interfaces with GTK that require knowledge of the GCC compiler. First I install gtk3-devel package:
dnf install gtk3-devel 
The Fedora team come with a group install with many feature.
#dnf -y groupinstall "Development Tools"
I test with these examples:
#include 

int main(int   argc,
     char *argv[])
{
  GtkWidget *window;
    
  gtk_init (&argc, &argv);
    
  window = gtk_window_new (GTK_WINDOW_TOPLEVEL);
  gtk_window_set_title (GTK_WINDOW (window), "Hello World");
  gtk_widget_show  (window);
    
  gtk_main ();
    
  return 0;
}
This create a simple window with Hello World title.
#include 

static void on_window_closed(GtkWidget * widget, gpointer data)
{
    gtk_main_quit();
}

int main(int argc, char * argv[])
{
    GtkWidget * window, * label;

    gtk_init(&argc, &argv);

    window = gtk_window_new(GTK_WINDOW_TOPLEVEL);

    g_signal_connect( window, "destroy", G_CALLBACK(on_window_closed), NULL);

    label = gtk_label_new("Hello, World!");

    gtk_container_add(GTK_CONTAINER(window), label);

    gtk_widget_show(label);
    gtk_widget_show(window);

    gtk_main();

    return 0;
}
This is the same example but you will see a label with te text Hello, World!.
The last example is more complex and involves the use of signals attached to the close button and the OK button.
The main window contains three labels with my name and an editbox in which you have to enter my nickname mythcat or something else.
#include 

const char *password = "mythcat";

// close the window application 
void closeApp(GtkWidget *widget, gpointer data)
{
    gtk_main_quit();
}

// show text when you click on button 
void button_clicked(GtkWidget *button, gpointer data)
{
    const char *password_text = gtk_entry_get_text(GTK_ENTRY((GtkWidget *)data));

    if(strcmp(password_text, password) == 0)
        printf("Access granted for user: \"%s\"\n",password);
    else
        printf("Access denied!\n");
 
}

int main( int argc, char *argv[])
{
    GtkWidget *window;
    GtkWidget *label1, *label2, *label3;
    GtkWidget *hbox;
    GtkWidget *vbox;
    GtkWidget *ok_button;
    GtkWidget *password_entry;

    gtk_init(&argc, &argv);

    window = gtk_window_new(GTK_WINDOW_TOPLEVEL);

    gtk_window_set_title(GTK_WINDOW(window), "Labels, password with one button and layout");
    gtk_window_set_position(GTK_WINDOW(window), GTK_WIN_POS_CENTER);
    gtk_window_set_default_size(GTK_WINDOW(window), 300, 200);

    g_signal_connect(G_OBJECT(window), "destroy", G_CALLBACK(closeApp), NULL);

    label1 = gtk_label_new("Catalin");
    label2 = gtk_label_new("George");
    label3 = gtk_label_new("Festila");

    password_entry = gtk_entry_new();
    gtk_entry_set_visibility(GTK_ENTRY(password_entry), FALSE);
    ok_button = gtk_button_new_with_label("OK");
    g_signal_connect(G_OBJECT(ok_button), "clicked", G_CALLBACK(button_clicked),password_entry);

    hbox = gtk_box_new(FALSE, 1);
    vbox = gtk_box_new(TRUE, 2);

    gtk_box_pack_start(GTK_BOX(vbox), label1, TRUE, FALSE, 5);
    gtk_box_pack_start(GTK_BOX(vbox), label2, TRUE, FALSE, 5);
    gtk_box_pack_start(GTK_BOX(hbox), vbox, FALSE, TRUE, 5);
    gtk_box_pack_start(GTK_BOX(hbox), label3, FALSE, FALSE, 5);
    gtk_box_pack_start(GTK_BOX(vbox), ok_button, FALSE, FALSE, 5);
    gtk_box_pack_start(GTK_BOX(hbox), password_entry, TRUE, FALSE, 5);
    gtk_container_add(GTK_CONTAINER(window), hbox);

    gtk_widget_show_all(window);

    gtk_main();

    return 0;
} 
The result can be seen in the following image:

I put the source code for the last example in a test.c file and compiled it like this:
[mythcat@desk ~]$ gcc test.c $(pkg-config --cflags --libs gtk+-3.0) -o test
[mythcat@desk ~]$ ./test

Saturday, September 5, 2020

Fedora 32 : Can be better? part 007.

Another article in the Can be better? series that deals with a very popular feature called SELinux. Here that in this seventh part I will introduce you to the world of SELinux in my own style of simply explaining some SElinux configurations.
Let's recap some basic elements specific to SELinux.
Multi Category Security or MCS is a discretionary implementation of the mandatory Multi Level Security
MCS basically tries to use the MLS attributes: Security Levels and Security Compartments.
MCS implemented have one or more extra fields in their Security Context tuple: user_u:role_r:type_t:s0:c0.
You can see this with id -Z.
The MLS Range contains two components, the low (classification and compartments) and high (clearance).
sensitivity label build from the low component: s2 with c1, c2 ...
MCS does have 1024 categories that can be assigned to processes and files.
On an MLS system are two special labels, SystemLow(s0) and SystemHigh (s15:c0.c255).
The upper end of the MCS range is in an MCS environment s0:c0.c1023 is SystemHigh.
By default, everything in an MCS environment has access to SystemLow or s0.
You will able to access files with s0:c122 and s0:c123 categories.
The MLS translation mechanism to give a more literal meaning to the machine-like policy used in the MLS sensitivity and category declaration.
The MLS rule says: "no read up and no write down".
The MLS model is used to enforce confidentiality.
All processes that are forced to operate with Security Level.
The s0 Security Level or SystemLow level is the lower end of the Security Level Range in an MLS environment.
If you do not have the correct configurations then the SELinux setting operation for Enforcing could generate errors in the linux operation after reboot or during Linux operation.
You will need to have the root password and return for new SELinux settings.
Let's solve this issue: put SELinux into Enforce mode but give my user possibility to use command sudo su.
First, you need to see this table:
SELinux user Description Used for
unconfined_u SELinux user meant for unrestricted users. Unconfined users have hardly any restrictions in a SELinux context and are meant for systems where only Internet-facing services should run confined (i.e. the targeted SELinux policy store). All users on a targeted system
root The SELinux user meant for the root account The Linux root account
sysadm_u SELinux user with direct system administrative role assigned Linux accounts that only perform administrative tasks
staff_u SELinux user for operators that need to run both non-administrative commands (through the staff_r role) and administrative commands (through the sysadm_r role). Linux accounts used for both end user usage as well as administrative tasks
user_u SELinux user for non-privileged accounts Unprivileged Linux accounts
system_u Special SELinux user meant for system services Not used directly
Is need to change my user mythcat to staff_u with a good MLS Range.
[root@desk mythcat]# semanage login --modify --seuser staff_u --range s2:c100 mythcat
[root@desk mythcat]# semanage login --modify --seuser staff_u --range s0-s15:c0.c1023 mythcat
[root@desk mythcat]# semanage login -l 
[root@desk mythcat]# setenforce enforcing
[root@desk mythcat]# getenforce
Enforcing
[root@desk mythcat]# semanage login -l 
ValueError: Cannot read policy store.
After reboot need some time to load the new changes, first is the last configuration.
[mythcat@desk ~]$ semanage login -l
ValueError: SELinux policy is not managed or store cannot be accessed.
[mythcat@desk ~]$ id -Z
staff_u:staff_r:staff_t:s0-s15:c0.c1023
[mythcat@desk ~]$ sestatus 
SELinux status: enabled
SELinuxfs mount: /sys/fs/selinux
SELinux root directory: /etc/selinux
Loaded policy name: mls
Current mode: permissive
Mode from config file: permissive
Policy MLS status: enabled
Policy deny_unknown status: denied
Memory protection checking: actual (secure)
Max kernel policy version: 33
Few seconds later all is good:
[mythcat@desk ~]$ sudo su 
[sudo] password for mythcat: 
bash: /root/.bashrc: Permission denied
bash-5.0# ls
bash-5.0# sestatus 
SELinux status: enabled
SELinuxfs mount: /sys/fs/selinux
SELinux root directory: /etc/selinux
Loaded policy name: mls
Current mode: enforcing
Mode from config file: permissive
Policy MLS status: enabled
Policy deny_unknown status: denied
Memory protection checking: actual (secure)
Max kernel policy version: 33
bash-5.0# id -Z
staff_u:staff_r:staff_t:s0-s15:c0.c1023
bash-5.0# exit 
exit
[mythcat@desk ~]$ sestatus 
SELinux status: enabled
SELinuxfs mount: /sys/fs/selinux
SELinux root directory: /etc/selinux
Loaded policy name: mls
Current mode: enforcing
Mode from config file: permissive
Policy MLS status: enabled
Policy deny_unknown status: denied
Memory protection checking: actual (secure)
Max kernel policy version: 33
Everything is fine for now, this delay is the reason for using the selinux kernel settings. More information about Multi-Level Security and Multi-Category Security can be found on this webpage.

Tuesday, August 25, 2020

Fedora 32 : Change display manager.

The display manager is a graphical login manager which starts a session, simply asks username and password to login desktop.
On Fedora, you can choose for example GDM (Gnome Display Manager), SDDM (Simple Desktop Display Manager), LXDM (LXDE Display Manager), LightDM, KDM (KDE Display Manager), XDM (X Display Manager).
I like the old gdm display manager, is good and works great.
If you want to change it then use these commands:
[root@desk mythcat]# dnf install gdm
...
Complete!
[root@desk mythcat]# systemctl disable lightdm 
[root@desk mythcat]# systemctl enable gdm
Failed to enable unit: File /etc/systemd/system/display-manager.service already exists and is a symlink to /usr/lib/systemd/system/sddm.service.
[root@desk mythcat]# systemctl disable sddm.service 
Removed /etc/systemd/system/display-manager.service.
[root@desk mythcat]# systemctl enable gdm
Created symlink /etc/systemd/system/display-manager.service → /usr/lib/systemd/system/gdm.service.
[root@desk mythcat]# reboot
If you have problems with gdm display manager then you can read about settings here.
The configuration file can be found in this file:
[root@desk mythcat]# cat /etc/gdm/custom.conf 
# GDM configuration storage

[daemon]
# Uncomment the line below to force the login screen to use Xorg
#WaylandEnable=false
AutomaticLogin=mythcat
AutomaticLoginEnable=False
[security]

[xdmcp]

[chooser]

[debug]
# Uncomment the line below to turn on debugging
#Enable=true 

Sunday, August 23, 2020

Fedora 32 : Install LibreOffice_7.0.0 .

The latest releases of LibreOffice is version 7.0.0 and is available for Fedora 32 distro from here. To install it you need to use these commands:
[root@desk mythcat]# dnf -y update
...
[mythcat@desk ~]$ cp Downloads/LibreOffice_7.0.0_Linux_x86-64_rpm.tar.gz ~
[mythcat@desk ~]$ ls LibreOffice*
LibreOffice_7.0.0_Linux_x86-64_rpm.tar.gz
[mythcat@desk ~]$ tar xvf LibreOffice_7.0.0_Linux_x86-64_rpm.tar.gz 
LibreOffice_7.0.0.3_Linux_x86-64_rpm/
LibreOffice_7.0.0.3_Linux_x86-64_rpm/RPMS/
...
[mythcat@desk ~]$ cd LibreOffice_7.0.0.3_Linux_x86-64_rpm/
[mythcat@desk LibreOffice_7.0.0.3_Linux_x86-64_rpm]$ cd RPMS/
[mythcat@desk RPMS]$ sudo dnf install *.rpm
[sudo] password for mythcat: 
Last metadata expiration check: 2:09:12 ago on Sat 22 Aug 2020 10:33:11 PM EEST.
Dependencies resolved.
================================================================================
 Package                                    Arch   Version   Repository    Size
================================================================================
Installing:
 libobasis7.0-base                          x86_64 7.0.0.3-3 @commandline 1.8 M
 libobasis7.0-calc                          x86_64 7.0.0.3-3 @commandline 9.5 M
 libobasis7.0-core                          x86_64 7.0.0.3-3 @commandline 101 M
 libobasis7.0-draw                          x86_64 7.0.0.3-3 @commandline 6.1 k
 libobasis7.0-en-US                         x86_64 7.0.0.3-3 @commandline  88 k
...
Complete!
The last step is to run this software from Fedora 32 distro desktop environment.

Tuesday, August 18, 2020

Fedora 32 : Repair the starting LightDM display manager.

LightDM is a cross-desktop display manager with these features:
  • Cross-desktop - supports different desktop technologies.
  • Supports different display technologies (X, Mir, Wayland ...).
  • Lightweight - low memory usage and high performance.
  • Supports guest sessions.
  • Supports remote login (incoming - XDMCP, VNC, outgoing - XDMCP, pluggable).
  • Comprehensive test suite. 
  • Low code complexity.
To start it you need to use these commands:
[mythcat@desk ~]$ sudo systemctl get-default
[sudo] password for mythcat: 
multi-user.target
[mythcat@desk ~]$ sudo systemctl set-default graphical.target
Removed /etc/systemd/system/default.target.
Created symlink /etc/systemd/system/default.target → /usr/lib/systemd/system/graphical.target.
Restart your Fedora distro and use it.

Saturday, August 15, 2020

Fedora 32 : Accurate timekeeping with chronyd daemon.

Accurate timekeeping is important in networking because accurate time stamps in packets and logs are required.
In Linux operating systems, the NTP protocol is implemented by a daemon running in userspace.
For Fedora distro, you can choose between the daemons ntpd and chronyd. Today I will show you how to use the chronyd.
The Fedora documentation can be found on the official website.
Let's install and use this:
[root@desk mythcat]# dnf install chrony 
...
[root@desk mythcat]# vim /etc/chrony.conf 
With the vim tool now you can add the In most cases, it's best to use pool.ntp.org to find an NTP server or use servers from your country. Now, I can start and enable the daemons named chronyd and add it to the firewall.
[root@desk mythcat]# systemctl start chronyd 
[root@desk mythcat]# systemctl status chronyd 
● chronyd.service - NTP client/server
     Loaded: loaded (/usr/lib/systemd/system/chronyd.service; enabled; vendor p>
     Active: active (running) since Sat 2020-08-15 12:23:08 EEST; 9h ago
       Docs: man:chronyd(8)
             man:chrony.conf(5)
   Main PID: 10071 (chronyd)
      Tasks: 1 (limit: 11800)
     Memory: 1.0M
        CPU: 93ms
     CGroup: /system.slice/chronyd.service
             └─10071 /usr/sbin/chronyd

Aug 15 12:23:08 desk systemd[1]: Starting NTP client/server...
Aug 15 12:23:08 desk chronyd[10071]: chronyd version 3.5 starting (+CMDMON +NTP>
Aug 15 12:23:08 desk chronyd[10071]: Frequency -13.819 +/- 0.344 ppm read from >
Aug 15 12:23:08 desk chronyd[10071]: Using right/UTC timezone to obtain leap se>
Aug 15 12:23:08 desk systemd[1]: Started NTP client/server.
Aug 15 12:23:13 desk chronyd[10071]: Selected source 78.96.7.25
Aug 15 12:23:13 desk chronyd[10071]: System clock TAI offset set to 37 seconds

[root@desk mythcat]# systemctl enable chronyd 
[root@desk mythcat]# firewall-cmd --add-service=ntp --permanent 
success
[root@desk mythcat]# firewall-cmd --reload 
success
You can use it with chronyc command tool:
[root@desk mythcat]# chronyc sources 
210 Number of sources = 4
MS Name/IP address         Stratum Poll Reach LastRx Last sample               
===============================================================================
^+ blackmamba-g0.eff.ro          3  10   377   692  -1192us[-1273us] +/-   92ms
^+ corporate1.bluepink.ro        2  10   377   200  -1441us[-1441us] +/-   52ms
^+ static-5-2-155-141.rdsne>     2  10   377   468  +1622us[+1540us] +/-   51ms
^* dummy.upcnet.ro               2  10   377   435  -1221us[-1303us] +/-   57ms
[root@desk mythcat]# chronyc tracking
Reference ID    : 4E600719 (dummy.upcnet.ro)
Stratum         : 3
Ref time (UTC)  : Sat Aug 15 19:06:18 2020
System time     : 0.000439648 seconds fast of NTP time
Last offset     : -0.000081712 seconds
RMS offset      : 0.000591977 seconds
Frequency       : 13.753 ppm slow
Residual freq   : -0.000 ppm
Skew            : 0.235 ppm
Root delay      : 0.069966756 seconds
Root dispersion : 0.017129980 seconds
Update interval : 1036.2 seconds
Leap status     : Normal
[root@desk mythcat]# chronyc activity
200 OK
4 sources online
0 sources offline
0 sources doing burst (return to online)
0 sources doing burst (return to offline)
0 sources with unknown address 

Friday, August 7, 2020

Fedora 32 : First example with C# on Fedora distro.

Let's enable the COPR repository for dotnet:
[mythcat@desk ~]$ sudo dnf copr enable @dotnet-sig/dotnet
[sudo] password for mythcat: 
Enabling a Copr repository. Please note that this repository is not part
of the main distribution, and quality may vary.

The Fedora Project does not exercise any power over the contents of
this repository beyond the rules outlined in the Copr FAQ at
,
and packages are not held to any quality or security level.

Please do not file bug reports about these packages in Fedora
Bugzilla. In case of problems, contact the owner of this repository.

Do you really want to enable copr.fedorainfracloud.org/@dotnet-sig/dotnet? [y/N]: y
Repository successfully enabled.
Install the .NET Core package:
[mythcat@desk ~]$ sudo dnf install dotnet
Copr repo for dotnet owned by @dotnet-sig         42 kB/s |  59 kB     00:01    
Dependencies resolved.
=================================================================================
 Package                           Arch      Version            Repository  Size
=================================================================================
Installing:
 dotnet                            x86_64    3.1.106-1.fc32     updates     11 k
Installing dependencies:
 aspnetcore-runtime-3.1            x86_64    3.1.6-1.fc32       updates    6.2 M
 aspnetcore-targeting-pack-3.1     x86_64    3.1.6-1.fc32       updates    945 k
 dotnet-apphost-pack-3.1           x86_64    3.1.6-1.fc32       updates     70 k
 dotnet-host                       x86_64    3.1.6-1.fc32       updates    104 k
 dotnet-hostfxr-3.1                x86_64    3.1.6-1.fc32       updates    164 k
 dotnet-runtime-3.1                x86_64    3.1.6-1.fc32       updates     27 M
 dotnet-sdk-3.1                    x86_64    3.1.106-1.fc32     updates     41 M
 dotnet-targeting-pack-3.1         x86_64    3.1.6-1.fc32       updates    1.8 M
 dotnet-templates-3.1              x86_64    3.1.106-1.fc32     updates    1.8 M
 netstandard-targeting-pack-2.1    x86_64    3.1.106-1.fc32     updates    1.3 M

Transaction Summary
=================================================================================
Install  11 Packages

Total download size: 79 M
Installed size: 298 M
Is this ok [y/N]: 
...
Use this tutorial to install Visual Studio Code. Press Ctr-P keys to install the C# extension by OmniSharp.
ext install ms-dotnettools.csharp
The last step is to create a application HelloWorld:
[mythcat@desk ~]$ dotnet new console -o HelloWorld

Welcome to .NET Core 3.1!
---------------------
SDK Version: 3.1.106

----------------
Explore documentation: https://aka.ms/dotnet-docs
Report issues and find source on GitHub: https://github.com/dotnet/core
Find out what's new: https://aka.ms/dotnet-whats-new
Learn about the installed HTTPS developer cert: https://aka.ms/aspnet-core-https
Use 'dotnet --help' to see available commands or visit: https://aka.ms/dotnet-cli-docs
Write your first app: https://aka.ms/first-net-core-app
--------------------------------------------------------------------------------------
Getting ready...
The template "Console Application" was created successfully.

Processing post-creation actions...
Running 'dotnet restore' on HelloWorld/HelloWorld.csproj...
  Restore completed in 119.48 ms for /home/mythcat/HelloWorld/HelloWorld.csproj.

Restore succeeded.
You can run it with dotnet run command:
[mythcat@desk ~]$ cd HelloWorld/
[mythcat@desk HelloWorld]$ ls
HelloWorld.csproj  obj  Program.cs
[mythcat@desk HelloWorld]$ dotnet run Program.cs 
Hello World!

Sunday, August 2, 2020

Fedora 32 : Play games with Steam service.

Steam is a video game digital distribution service by Valve. It was launched as a standalone software client in September 2003 as a way for Valve to provide automatic updates for their games, and expanded to include games from third-party publishers., see Wikipedia.
Is very easy to install and play a game with Fedora 32 Linux distro, just follow these commands:
[mythcat@desk ~]$ sudo dnf update --refresh
[sudo] password for mythcat: 
Fedora 32 openh264 (From Cisco) - x86_64        1.1 kB/s | 986  B     00:00    
Fedora Modular 32 - x86_64                       39 kB/s |  22 kB     00:00    
Fedora Modular 32 - x86_64 - Updates             26 kB/s |  22 kB     00:00    
Fedora 32 - x86_64 - Updates                     10 kB/s | 9.8 kB     00:00    
Fedora 32 - x86_64                               20 kB/s |  23 kB     00:01    
google-chrome                                   7.6 kB/s | 1.3 kB     00:00    
MEGAsync                                        4.7 kB/s | 1.5 kB     00:00    
MongoDB Repository                              4.4 kB/s | 2.5 kB     00:00    
RPM Fusion for Fedora 32 - Free - Updates        21 kB/s | 9.1 kB     00:00    
RPM Fusion for Fedora 32 - Free                  25 kB/s |  10 kB     00:00    
RPM Fusion for Fedora 32 - Nonfree - Updates     20 kB/s | 9.3 kB     00:00    
RPM Fusion for Fedora 32 - Nonfree               18 kB/s |  10 kB     00:00    
Visual Studio Code                              6.6 kB/s | 3.0 kB     00:00    
Dependencies resolved.
Nothing to do.
Complete!
[mythcat@desk ~]$ sudo dnf install steam -y
Last metadata expiration check: 0:00:09 ago on Sun 02 Aug 2020 04:59:49 PM EEST.
Package steam-1.0.0.64-1.fc32.i686 is already installed.
Dependencies resolved.
Nothing to do.
Complete!
[mythcat@desk ~]$ steam 
Running Steam on fedora 32 64-bit
STEAM_RUNTIME is enabled automatically
Pins potentially out-of-date, rebuilding...
...
Now you can pick a game from store steam and play it.

Tuesday, July 28, 2020

Fedora 32 : Play Minecraft with TLauncher.

Today I will show you how you can install java and use TLauncher to play Minecraft game on Fedora 32.
You need to have version Java 9 or 10 in order to use this software.
First, download the archive from the official website.
Create a folder name and unzip it into this folder and use these commands:
[mythcat@desk TLauncher]$ ls
README-EN.txt  README-RUS.txt  TLauncher-2.72.jar
[mythcat@desk TLauncer]$ sudo su 
[root@desk TLauncher]# dnf list java* | grep openjdk-devel
java-latest-openjdk-devel.x86_64                  1:14.0.1.7-2.rolling.fc32        @updates
java-1.8.0-openjdk-devel.x86_64                   1:1.8.0.262.b10-1.fc32           updates 
java-1.8.0-openjdk-devel-slowdebug.i686           1:1.8.0.262.b10-1.fc32           updates 
java-1.8.0-openjdk-devel-slowdebug.x86_64         1:1.8.0.262.b10-1.fc32           updates 
java-11-openjdk-devel.i686                        1:11.0.8.10-2.fc32               updates 
java-11-openjdk-devel.x86_64                      1:11.0.8.10-2.fc32               updates 
java-11-openjdk-devel-slowdebug.x86_64            1:11.0.8.10-2.fc32               updates 
java-latest-openjdk-devel.i686                    1:14.0.1.7-2.rolling.fc32        updates 
java-latest-openjdk-devel-slowdebug.x86_64        1:14.0.1.7-2.rolling.fc32        updates 
[root@desk TLauncher]# dnf install java-11-openjdk.x86_64
Last metadata expiration check: 0:09:17 ago on Tue 28 Jul 2020 09:33:24 PM EEST.
Dependencies resolved.
=====================================================================================================================
 Package                              Architecture       Version                           Repository           Size
=====================================================================================================================
Installing:
 java-11-openjdk                      x86_64             1:11.0.8.10-2.fc32                updates             251 k
Installing dependencies:
 java-11-openjdk-headless             x86_64             1:11.0.8.10-2.fc32                updates              38 M
 ttmkfdir                             x86_64             3.0.9-58.fc32                     fedora               58 k
 xorg-x11-fonts-Type1                 noarch             7.5-24.fc32                       fedora              500 k

Transaction Summary
=====================================================================================================================
Install  4 Packages

Total download size: 39 M
Installed size: 173 M
Is this ok [y/N]: y
...
[root@desk TLauncher]# sudo alternatives --config java

There are 4 programs which provide 'java'.

  Selection    Command
-----------------------------------------------
   1           /opt/jdk1.8.0_232/bin/java
   2           /opt/jdk1.8.0_201/bin/java
*+ 3           java-1.8.0-openjdk.x86_64 (/usr/lib/jvm/java-1.8.0-openjdk-1.8.0.262.b10-1.fc32.x86_64/jre/bin/java)
   4           java-11-openjdk.x86_64 (/usr/lib/jvm/java-11-openjdk-11.0.8.10-2.fc32.x86_64/bin/java)

Enter to keep the current selection[+], or type selection number: 4
[root@desk TLauncher]# export JAVA_HOME=/usr/lib/jvm/java-11-openjdk-11.0.8.10-2.fc32.x86_64/
[root@desk TLauncher]# echo $JAVA_HOME
/usr/lib/jvm/java-11-openjdk-11.0.8.10-2.fc32.x86
[root@desk TLauncher]# java -version
openjdk version "11.0.8" 2020-07-14
OpenJDK Runtime Environment 18.9 (build 11.0.8+10)
OpenJDK 64-Bit Server VM 18.9 (build 11.0.8+10, mixed mode, sharing)
Now you can start the program:
[mythcat@desk TLauncher]$ sudo java -jar TLauncher-2.72.jar

-------------------------------------------------------------------
run double running protection
[Downloader2] Loaded configuration: normal
[Downloader2] Files in queue 15
[Downloader2] Starting download 15 files...
...
The last command will run the software and you will able to play the game.

Saturday, July 11, 2020

Fedora 32 : Upgrade from Fedora 31 to the new Fedora 32.

Today I managed to upgrade to Fedora 32.
After some time I started the system and used the tutorial from here.
I also used the following Linux commands:
#sudo dnf distro-sync --allowerasing
#dnf reinstall xorg-\* mesa\* libglvnd\*
In the following image, you can see the new upgrade works very well with my Cinnamon desktop environment.

Tuesday, February 25, 2020

Fedora 31 : Install Unity 3D on Fedora Linux.

If you want to install the Unity 3D software on Fedora 31 Linux distro then you can read my tutorial from this webpage.
To run Unity software you need to have one good hardware.
This install require to upload the license file even you use a free or pro license.

Tuesday, February 18, 2020

Fedora 31 : The Fyne UI toolkit for Go programming language.

Today I will show you how to use a UI toolkit with the Go programming. language. The development team comes with this toolkit at the GitHub official webpage.
Fyne is an easy to use UI toolkit and app API written in Go. It is designed to build applications that run on desktop and mobile devices with a single codebase...
[mythcat@desk ~]$ sudo dnf install golang
[sudo] password for mythcat:
...
Installed:
  golang-1.13.6-1.fc31.x86_64            golang-bin-1.13.6-1.fc31.x86_64       
  golang-src-1.13.6-1.fc31.noarch        mercurial-4.9-2.fc31.x86_64           

Complete! 
First is need to install these packages with DNF tool:
[root@desk mythcat]# dnf install libX11-devel libXcursor-devel libXrandr-devel libXinerama-devel 
mesa-libGL-devel libXi-devel
Last metadata expiration check: 0:04:28 ago on Sun 16 Feb 2020 12:25:04 PM EET.
Package libX11-devel-1.6.9-2.fc31.x86_64 is already installed.
Package mesa-libGL-devel-19.2.8-1.fc31.x86_64 is already installed.
Package libXi-devel-1.7.10-2.fc31.x86_64 is already installed.
Dependencies resolved.
...

Installed:
  libXcursor-devel-1.1.15-6.fc31.x86_64           libXinerama-devel-1.1.4-4.fc31.x86_64           
  libXrandr-devel-1.5.2-2.fc31.x86_64             libXrender-devel-0.9.10-10.fc31.x86_64          

Complete! 
Let's install the fyne toolkit and the demo application:
[mythcat@desk ~]$ go get fyne.io/fyne
[mythcat@desk ~]$ go get fyne.io/fyne/cmd/fyne_demo/
I run the demo with this command and works very well:
[mythcat@desk ~]$ go run /home/mythcat/go/src/fyne.io/fyne/cmd/fyne_demo/main.go  

Sunday, February 16, 2020

Fedora 31 : Can be better? part 006.

I try to use the Selinux MLS with Fedora 31 and I wrote on my last article about Fedora 31 : Can be better? part 005. After relabeling the files and start the environment I get multiple errors and I ask an answer at fedoraproject lists: This is an example of the problem of implementing MLS in Fedora and can be remedied because MLS Selinux is old in implementing Selinux.

SELinux is preventing su from open access on the file /var/log/lastlog.

*****  Plugin catchall (100. confidence) suggests   **************************

If you believe that su should be allowed open access on the lastlog file by default.
Then you should report this as a bug.
You can generate a local policy module to allow this access.
Do
allow this access for now by executing:
# ausearch -c 'su' --raw | audit2allow -M my-su
# semodule -X 300 -i my-su.pp 
I try to fix it but I got this error:
[root@desk mythcat]# ausearch -c 'su' --raw | audit2allow -M my-su
compilation failed:
my-su.te:36:ERROR 'syntax error' at token 'mlsconstrain' on line 36:
mlsconstrain file { write create setattr relabelfrom append unlink link rename mounton } ((l1 eq l2 -Fail-)  
or (t1 == mlsfilewritetoclr -Fail-)  and (h1 dom l2 -Fail-)  and (l1 domby l2)  or (t2 == 
mlsfilewriteinrange -Fail-)  
and (l1 dom l2 -Fail-)  an
# mlsconstrain file { read getattr execute } ((l1 dom l2 -Fail-)  or (t1 == 
mlsfilereadtoclr -Fail-)  
and (h1 dom l2 -Fail-)  or (t1 == mlsfileread -Fail-)  or (t2 == mlstrustedobject -Fail-) ); Constraint DENIED
/usr/bin/checkmodule:  error(s) encountered while parsing configuration
[root@desk mythcat]# ausearch -c 'su' --raw | audit2allow -M my-su
compilation failed:
my-su.te:36:ERROR 'syntax error' at token 'mlsconstrain' on line 36:
mlsconstrain file { write create setattr relabelfrom append unlink link rename mounton } ((l1 eq l2 -Fail-)  
or (t1 == mlsfilewritetoclr -Fail-)  and (h1 dom l2 -Fail-)  and (l1 domby l2)  or (t2 == 
mlsfilewriteinrange -Fail-)  
and (l1 dom l2 -Fail-)  an
# mlsconstrain file { read getattr execute } ((l1 dom l2 -Fail-)  or (t1 == 
mlsfilereadtoclr -Fail-)  
and (h1 dom l2 -Fail-)  or (t1 == mlsfileread -Fail-)  or (t2 == mlstrustedobject -Fail-) ); Constraint DENIED
/usr/bin/checkmodule:  error(s) encountered while parsing configuration...

Tuesday, February 11, 2020

Fedora 31 : Install the drawing GNOME with DNF and flatpak.

You can use the DNF tool:
[root@desk mythcat]# dnf search gnome | grep drawing 
Last metadata expiration check: 1:53:53 ago on Tue 11 Feb 2020 05:28:15 PM EET.
drawing.noarch : Drawing application for the GNOME desktop
[root@desk mythcat]# dnf install drawing.noarch 
Last metadata expiration check: 1:54:28 ago on Tue 11 Feb 2020 05:28:15 PM EET.
Dependencies resolved.
================================================================================
 Package          Architecture    Version                Repository        Size
================================================================================
Installing:
 drawing          noarch          0.4.9-1.fc31           updates          1.0 M

Transaction Summary
================================================================================
Install  1 Package

Total download size: 1.0 M
Installed size: 1.5 M
Is this ok [y/N]: y
Downloading Packages:
drawing-0.4.9-1.fc31.noarch.rpm                 1.4 MB/s | 1.0 MB     00:00    
--------------------------------------------------------------------------------
Total                                           601 kB/s | 1.0 MB     00:01     
Running transaction check
Transaction check succeeded.
Running transaction test
Transaction test succeeded.
Running transaction
  Preparing        :                                                        1/1 
  Installing       : drawing-0.4.9-1.fc31.noarch                            1/1 
  Running scriptlet: drawing-0.4.9-1.fc31.noarch                            1/1 
  Verifying        : drawing-0.4.9-1.fc31.noarch                            1/1 

Installed:
  drawing-0.4.9-1.fc31.noarch                                                   

Complete!
This install use the flatpak tool:
[root@desk mythcat]# dnf install flatpak
Last metadata expiration check: 1:47:49 ago on Tue 11 Feb 2020 05:28:15 PM EET.
Dependencies resolved.
================================================================================
 Package                     Arch        Version             Repository    Size
================================================================================
Installing:
 flatpak                     x86_64      1.4.3-3.fc31        updates      1.1 M
Installing dependencies:
 flatpak-selinux             noarch      1.4.3-3.fc31        updates       24 k
 flatpak-session-helper      x86_64      1.4.3-3.fc31        updates       72 k
Installing weak dependencies:
 p11-kit-server              x86_64      0.23.20-1.fc31      updates      186 k
 xdg-desktop-portal          x86_64      1.4.2-3.fc31        fedora       386 k
 xdg-desktop-portal-gtk      x86_64      1.4.0-1.fc31        fedora       212 k

Transaction Summary
================================================================================
Install  6 Packages

Total download size: 1.9 M
Installed size: 7.7 M
Is this ok [y/N]: y
...
Installed:
  flatpak-1.4.3-3.fc31.x86_64                                                   
  flatpak-selinux-1.4.3-3.fc31.noarch                                           
  flatpak-session-helper-1.4.3-3.fc31.x86_64                                    
  p11-kit-server-0.23.20-1.fc31.x86_64                                          
  xdg-desktop-portal-1.4.2-3.fc31.x86_64                                        
  xdg-desktop-portal-gtk-1.4.0-1.fc31.x86_64                                    

Complete! 
Let's install the flatpakrepo:
[mythcat@desk ~]$ flatpak remote-add --if-not-exists flathub https://flathub.org/repo/flathub.flatpakrepo

Note that the directories 

'/var/lib/flatpak/exports/share'
'/home/mythcat/.local/share/flatpak/exports/share'

are not in the search path set by the XDG_DATA_DIRS environment variable, so
applications installed by Flatpak may not appear on your desktop until the
session is restarted.
[mythcat@desk ~]$ flatpak install flathub com.github.maoschanz.drawing

Note that the directories 

'/var/lib/flatpak/exports/share'
'/home/mythcat/.local/share/flatpak/exports/share'

are not in the search path set by the XDG_DATA_DIRS environment variable, so
applications installed by Flatpak may not appear on your desktop until the
session is restarted.

Looking for matches…
Required runtime for com.github.maoschanz.drawing/x86_64/stable (runtime/org.gnome.Platform/x86_64/3.34)
 found in remote flathub
Do you want to install it? [Y/n]: Y

com.github.maoschanz.drawing permissions:
    ipc   wayland   x11



        ID                                   Arch   Branch Remote  Download
 1. [✓] org.gnome.Platform                   x86_64 3.34   flathub 304.2 MB / 318.5 MB
 2. [✓] org.gnome.Platform.Locale            x86_64 3.34   flathub  16.8 kB / 322.0 MB
 3. [✓] org.freedesktop.Platform.GL.default  x86_64 19.08  flathub  92.6 MB / 92.6 MB
 4. [✓] org.freedesktop.Platform.VAAPI.Intel x86_64 19.08  flathub   8.7 MB / 8.7 MB
 5. [✗] org.freedesktop.Platform.openh264    x86_64 19.08  flathub 594.2 kB / 593.4 kB
 6. [✓] com.github.maoschanz.drawing         x86_64 stable flathub   1.0 MB / 1.1 MB
 7. [✓] com.github.maoschanz.drawing.Locale  x86_64 stable flathub   1.7 kB / 86.2 kB

Warning: org.freedesktop.Platform.openh264 not installed
Installation complete.
[mythcat@desk ~]$ flatpak install org.freedesktop.Platform/x86_64/19.08

Note that the directories 

'/var/lib/flatpak/exports/share'
'/home/mythcat/.local/share/flatpak/exports/share'

are not in the search path set by the XDG_DATA_DIRS environment variable, so
applications installed by Flatpak may not appear on your desktop until the
session is restarted.

Looking for matches…
Found similar ref(s) for ‘org.freedesktop.Platform/x86_64/19.08’ in remote ‘flathub’ (system).
Use this remote? [Y/n]: Y


        ID                                Arch   Branch Remote  Download
 1. [✓] org.freedesktop.Platform          x86_64 19.08  flathub  11.5 MB / 238.1 MB
 2. [✓] org.freedesktop.Platform.Locale   x86_64 19.08  flathub  16.7 kB / 318.2 MB
 3. [✓] org.freedesktop.Platform.openh264 x86_64 19.08  flathub 593.6 kB / 593.4 kB

Installation complete. 
Restart the session and run it with this command:
[mythcat@desk ~]$ flatpak run com.github.maoschanz.drawing

Sunday, February 2, 2020

Fedora 31 : Can be better? part 005.

Today we have once again dealt with this topic on the possibilities of improving the Fedora distro.
This time the adventure turned to the Selinux system switching to SELinux MLS.
Let's test the SELinux Fedora 31 from default targeted to mls.
First let's see the users:
[root@desk mythcat]# semanage user -l

                Labeling   MLS/       MLS/                          
SELinux User    Prefix     MCS Level  MCS Range                      SELinux Roles

guest_u         user       s0         s0                             guest_r
root            user       s0         s0-s0:c0.c1023                 staff_r sysadm_r system_r unconfined_r
staff_u         user       s0         s0-s0:c0.c1023                 staff_r sysadm_r system_r unconfined_r
sysadm_u        user       s0         s0-s0:c0.c1023                 sysadm_r
system_u        user       s0         s0-s0:c0.c1023                 system_r unconfined_r
unconfined_u    user       s0         s0-s0:c0.c1023                 system_r unconfined_r
user_u          user       s0         s0                             user_r
xguest_u        user       s0         s0                             xguest_r
To use the MLS you need to change this file:
[root@desk mythcat]# vim /etc/selinux/config


# This file controls the state of SELinux on the system.
# SELINUX= can take one of these three values:
#     enforcing - SELinux security policy is enforced.
#     permissive - SELinux prints warnings instead of enforcing.
#     disabled - No SELinux policy is loaded.
SELINUX=enforcing
# SELINUXTYPE= can take one of these three values:
#     targeted - Targeted processes are protected,
#     minimum - Modification of targeted policy. Only selected processes are protected. 
#     mls - Multi Level Security protection.
SELINUXTYPE=targeted
The changes are:

#SELINUX=enforcing
SELINUX=permissive
...
#SELINUXTYPE=targeted
SELINUXTYPE=mls
Is need to install these packages:
[root@desk mythcat]# dnf search mls | grep selinux
Last metadata expiration check: 2:45:09 ago on Sun 02 Feb 2020 01:28:54 PM EET.
selinux-policy-mls.noarch : SELinux mls base policy
[root@desk mythcat]# dnf install selinux-policy-mls.noarch
...
Installed:
  mcstrans-2.9-2.fc31.x86_64                                                    
  policycoreutils-newrole-2.9-5.fc31.x86_64                                     
  selinux-policy-mls-3.14.4-45.fc31.noarch                                      

Complete!
These commands will relabel and start the MLS.
[mythcat@desk ~]$ setenforce 0
[mythcat@desk ~]$ getenforce
Permissive
...
[root@desk mythcat]# touch /.autorelabel
[root@desk mythcat]# reboot
If you have problems on boot the add selinux=0 on boot kernel.
After I boot and relabel all files I got errors about Gtk-Messages.
I remove my old Cinnamon with this command:
[root@desk mythcat]# dnf groupremove -y "Cinnnamon"
I list all my group with dnf tool:
[root@desk mythcat]# dnf grouplist -v 
I install the MATE environment:
dnf groupinstall -y "MATE Desktop" --allowerasing
After that the only way to start the environement is this command:
[mythcat@desk ~]$ sudo systemctl restart lightdm.service
Another issue comes from SELinux Alert Browser, where I get multiple alerts and these need to fix manually.
First, these alerts are more than 250.
After I fix some of these now I see only 50.
I think this problem with changing the SELinux type can be improved.

Fedora 31 : Using the dmesg command on Linux operating system.

The dmesg command is used to display the kernel-related messages on Unix like systems. Today I will show you how to use this command on the Linux operating system. Simply use the command:
[mythcat@desk ~]$ dmesg 
[    0.000000] microcode: microcode updated early to revision 0x21, date = 2019-02-13
...
Show the latest message that fits on screen:
[mythcat@desk ~]$ dmesg | less
... 
Use it to see infoermation about motherboard:
[mythcat@desk ~]$ dmesg | grep -i memory
...
[mythcat@desk ~]$ dmesg | grep -i dma
...
[mythcat@desk ~]$ dmesg | grep -i usb
...
[mythcat@desk ~]$ dmesg | grep -i tty
...
Same reult with a single command using multiple grep option:
[mythcat@desk ~]$ dmesg | grep -E "memory|dma|usb|tty"
This display logs related to error and warning:
[root@desk mythcat]# dmesg --level=err,warn
The dmesg comes with supported log facilities:
  • kern - kernel messages;
  • user - random user-level messages;
  • mail - mail system;
  • daemon - system daemons;
  • auth - security/authorization messages;
  • syslog - messages generated internally by syslogd;
  • lpr - line printer subsystem;
  • news - network news subsystem;
See output facility only for one:
[mythcat@desk ~]$ dmesg --facility=daemon
Use root user to clear dmesg logs after the reading them:
[root@desk mythcat]# dmesg -C
If you want then you can show the outpout into the colored messages:
# dmesg -L

Tuesday, January 28, 2020

Fedora 31 : Can be better? part 004.

Another issue on Fedora can be linked to the management of transactions to avoid transaction lock. Let's see how can be fixed:
[root@desk mythcat]# rpm --rebuilddb
warning: waiting for transaction lock on /var/lib/rpm/.rpm.lock
^C
[root@desk mythcat]# rm /var/lib/rpm/.rpm.lock
rm: remove regular empty file '/var/lib/rpm/.rpm.lock'? y
[root@desk mythcat]# rpm --rebuilddb
...
[root@desk mythcat]# dnf clean all
...
Waiting for process with pid 2128 to finish.
^CKeyboardInterrupt: Terminated.
[root@desk mythcat]# kill  -9 2128
[root@desk mythcat]# dnf clean all
95 files removed

Friday, January 24, 2020

Fedora 31 : The twa web auditor tool.

This tool comes with a good intro: A tiny web auditor with strong opinions.
The tool named twa takes one domain at a time and use these dependencies: bash 4, curl, dig, jq, and nc, along with the POSIX system.
The project can be found at GitHub repository but I can be install easy on Fedora 31 distro:
[root@desk mythcat]# dnf install twa.noarch 
Last metadata expiration check: 0:06:08 ago on Fri 24 Jan 2020 01:57:53 PM EET.
Dependencies resolved.
================================================================================
 Package       Architecture     Version                  Repository        Size
================================================================================
Installing:
 twa           noarch           1.8.0-3.fc31             fedora            18 k

Transaction Summary
================================================================================
Install  1 Package

Total download size: 18 k
Installed size: 30 k
Is this ok [y/N]: y
Downloading Packages:
twa-1.8.0-3.fc31.noarch.rpm                      10 kB/s |  18 kB     00:01    
--------------------------------------------------------------------------------
Total                                           6.7 kB/s |  18 kB     00:02     
Running transaction check
Transaction check succeeded.
Running transaction test
Transaction test succeeded.
Running transaction
  Preparing        :                                                        1/1 
  Installing       : twa-1.8.0-3.fc31.noarch                                1/1 
  Running scriptlet: twa-1.8.0-3.fc31.noarch                                1/1 
  Verifying        : twa-1.8.0-3.fc31.noarch                                1/1 

Installed:
  twa-1.8.0-3.fc31.noarch                                                       

Complete!
Let's see some examples with google website responses and this tool:
[mythcat@desk ~]$ twa google.com
FAIL(google.com): TWA-0102: HTTP redirects to HTTP (not secure)
FAIL(google.com): TWA-0205: Strict-Transport-Security missing
MEH(google.com): TWA-0206: X-Frame-Options is 'sameorigin', consider 'deny'
FAIL(google.com): TWA-0209: X-Content-Type-Options missing
FAIL(google.com): TWA-0210: X-XSS-Protection is '0'; XSS filtering disabled
FAIL(google.com): TWA-0214: Referrer-Policy missing
FAIL(google.com): TWA-0219: Content-Security-Policy missing
FAIL(google.com): TWA-0220: Feature-Policy missing
PASS(google.com): Site sends 'Server', but probably only a vendor ID: gws
PASS(google.com): Site doesn't send 'X-Powered-By'
PASS(google.com): Site doesn't send 'Via'
PASS(google.com): Site doesn't send 'X-AspNet-Version'
PASS(google.com): Site doesn't send 'X-AspNetMvc-Version'
PASS(google.com): No SCM repository at: http://google.com/.git/HEAD
PASS(google.com): No SCM repository at: http://google.com/.hg/store/00manifest.i
PASS(google.com): No SCM repository at: http://google.com/.svn/entries
PASS(google.com): No environment file at: http://google.com/.env
PASS(google.com): No environment file at: http://google.com/.dockerenv
PASS(google.com): No config file at: http://google.com/config.xml
PASS(google.com): No config file at: http://google.com/config.json
PASS(google.com): No config file at: http://google.com/config.yaml
PASS(google.com): No config file at: http://google.com/config.yml
PASS(google.com): No config file at: http://google.com/config.ini
^C
The output result line looks like this:
TYPE(domain): explanation where TYPE is one of PASS, MEH, FAIL, UNK, SKIP, and FATAL., see the output example:
PASS: The test passed with flying color.
MEH: The test passed, but with one or more things that could be improved.
FAIL: The test failed and should be fixed.
UNK: The server gave us something we didn't understand.
SKIP: The server gave us something we understood, but that we don't handle yet.
FATAL: A really important test failed, and should be fixed immediately.
Another feature is scoring.
The score format is this: npasses nmehs nfailures nunknowns nskips totally_screwed.
Let's see one example:
[mythcat@desk ~]$ twa google.com | tscore
20 37 2 7 0 0 0
The tool can be used with Alpine Docker container.

Tuesday, January 14, 2020

Fedora 31 : Install Yii framework.

Today I will show you how to install the Yii framework:
Yii is a fast, secure, and efficient PHP framework. Flexible yet pragmatic. Works right out of the box. Has reasonable defaults.
First, let's install the PHP , see the official webpage.
Fedora for PHP development.
[mythcat@desk ~]$ sudo dnf install php-cli
...
Is this ok [y/N]: y
Downloading Packages:
(1/2): php-common-7.3.13-1.fc31.x86_64.rpm      794 kB/s | 760 kB     00:00    
(2/2): php-cli-7.3.13-1.fc31.x86_64.rpm         2.2 MB/s | 2.8 MB     00:01    
--------------------------------------------------------------------------------
Total                                           1.6 MB/s | 3.5 MB     00:02     
Running transaction check
Transaction check succeeded.
Running transaction test
Transaction test succeeded.
Running transaction
  Preparing        :                                                        1/1 
  Installing       : php-common-7.3.13-1.fc31.x86_64                        1/2 
  Installing       : php-cli-7.3.13-1.fc31.x86_64                           2/2 
  Running scriptlet: php-cli-7.3.13-1.fc31.x86_64                           2/2 
  Verifying        : php-cli-7.3.13-1.fc31.x86_64                           1/2 
  Verifying        : php-common-7.3.13-1.fc31.x86_64                        2/2 

Installed:
  php-cli-7.3.13-1.fc31.x86_64          php-common-7.3.13-1.fc31.x86_64         

Complete!
Install these packages: PHPUnit for unit tests or Composer.
[mythcat@desk ~]$ sudo dnf install phpunit composer
...
Complete!
Install mysqli extension:
[mythcat@desk ~]$ sudo dnf install php-mysqli
...
Installed:
  php-mysqlnd-7.3.13-1.fc31.x86_64                                              

Complete!
You can start the server:
[mythcat@desk ~]$ sudo php --server localhost:8080 --docroot  .
PHP 7.3.13 Development Server started at Tue Jan 14 21:58:19 2020
Listening on http://localhost:8080
Document root is /home/mythcat
Press Ctrl-C to quit.
[Tue Jan 14 21:58:40 2020] [::1]:32988 [404]: / - No such file or directory
[Tue Jan 14 21:58:40 2020] [::1]:32990 [404]: / - No such file or directory
[Tue Jan 14 21:58:42 2020] [::1]:33014 [404]: /favicon.ico - No such file or directory
[Tue Jan 14 21:59:48 2020] [::1]:33080 [404]: / - No such file or directory
...
The composer command has these arguments:
[mythcat@desk ~]$ composer
   ______
  / ____/___  ____ ___  ____  ____  ________  _____
 / /   / __ \/ __ `__ \/ __ \/ __ \/ ___/ _ \/ ___/
/ /___/ /_/ / / / / / / /_/ / /_/ (__  )  __/ /
\____/\____/_/ /_/ /_/ .___/\____/____/\___/_/
                    /_/
Composer version 1.9.1 2019-11-01 17:20:17

Usage:
  command [options] [arguments]

Options:
  -h, --help                     Display this help message
  -q, --quiet                    Do not output any message
  -V, --version                  Display this application version
      --ansi                     Force ANSI output
      --no-ansi                  Disable ANSI output
  -n, --no-interaction           Do not ask any interactive question
      --profile                  Display timing and memory usage information
      --no-plugins               Whether to disable plugins.
  -d, --working-dir=WORKING-DIR  If specified, use the given directory as working directory.
      --no-cache                 Prevent use of the cache
  -v|vv|vvv, --verbose           Increase the verbosity of messages: 1 for normal output,
 2 for more verbose output and 3 for debug

Available commands:
  about                Shows the short information about Composer.
  archive              Creates an archive of this composer package.
  browse               Opens the package's repository URL or homepage in your browser.
  check-platform-reqs  Check that platform requirements are satisfied.
  clear-cache          Clears composer's internal package cache.
  clearcache           Clears composer's internal package cache.
  config               Sets config options.
  create-project       Creates new project from a package into given directory.
  depends              Shows which packages cause the given package to be installed.
  diagnose             Diagnoses the system to identify common errors.
  dump-autoload        Dumps the autoloader.
  dumpautoload         Dumps the autoloader.
  exec                 Executes a vendored binary/script.
  global               Allows running commands in the global composer dir ($COMPOSER_HOME).
  help                 Displays help for a command
  home                 Opens the package's repository URL or homepage in your browser.
  i                    Installs the project dependencies from the composer.lock file if present,
 or falls back on the composer.json.
  info                 Shows information about packages.
  init                 Creates a basic composer.json file in current directory.
  install              Installs the project dependencies from the composer.lock file if present,
 or falls back on the composer.json.
  licenses             Shows information about licenses of dependencies.
  list                 Lists commands
  outdated             Shows a list of installed packages that have updates available, including
 their latest version.
  prohibits            Shows which packages prevent the given package from being installed.
  remove               Removes a package from the require or require-dev.
  require              Adds required packages to your composer.json and installs them.
  run                  Runs the scripts defined in composer.json.
  run-script           Runs the scripts defined in composer.json.
  search               Searches for packages.
  show                 Shows information about packages.
  status               Shows a list of locally modified packages, for packages installed from source.
  suggests             Shows package suggestions.
  u                    Upgrades your dependencies to the latest version according to composer.json,
 and updates the composer.lock file.
  update               Upgrades your dependencies to the latest version according to composer.json,
 and updates the composer.lock file.
  upgrade              Upgrades your dependencies to the latest version according to composer.json,
 and updates the composer.lock file.
  validate             Validates a composer.json and composer.lock.
  why                  Shows which packages cause the given package to be installed.
  why-not              Shows which packages prevent the given package from being installed.
Let's install the Yii framework:
[mythcat@desk ~]$ composer create-project --prefer-dist yiisoft/yii2-app-basic basic

Installing yiisoft/yii2-app-basic (2.0.31)
  - Installing yiisoft/yii2-app-basic (2.0.31): Downloading (100%)         
Created project in basic
Loading composer repositories with package information
Updating dependencies (including require-dev)
...
Writing lock file
Generating autoload files
> yii\composer\Installer::postCreateProject
chmod('runtime', 0777)...done.
chmod('web/assets', 0777)...done.
chmod('yii', 0755)...done.
> yii\composer\Installer::postInstall 
Let's run it:
[mythcat@desk ~]$ cd basic/
[mythcat@desk basic]$ ./yii serve
Server started on http://localhost:8080/
Document root is "/home/mythcat/basic/web"
Quit the server with CTRL-C or COMMAND-C.
[Tue Jan 14 22:20:22 2020] [::1]:34072 [200]: /
[Tue Jan 14 22:20:22 2020] [::1]:34074 [200]: /assets/dd70c73/css/bootstrap.css
[Tue Jan 14 22:20:22 2020] [::1]:34076 [200]: /css/site.css
[Tue Jan 14 22:20:22 2020] [::1]:34078 [200]: /assets/afa8d426/jquery.js
[Tue Jan 14 22:20:22 2020] [::1]:34080 [200]: /assets/3235fb02/yii.js
[Tue Jan 14 22:20:22 2020] [::1]:34082 [200]: /assets/dd70c73/js/bootstrap.js
[Tue Jan 14 22:20:23 2020] [::1]:34084 [200]: /index.php?r=debug%2Fdefault%2Ftoolbar&tag=5e1e228626c18 

Monday, January 6, 2020

Fedora 31 : Can be better? part 004.

The common question of any Fedora Linux user: Can be better?.
Yes, we can fix some common errors...
This is a common error generated by the GTK on Fedora distro applications:
[mythcat@desk bin]$ ./studio.sh 

(java:12631): Gtk-WARNING **: 11:45:47.061: Unable to locate theme engine in module_path: "murrine",

(java:12631): Gtk-WARNING **: 11:45:47.061: Unable to locate theme engine in module_path: "murrine",

(java:12631): Gtk-WARNING **: 11:45:47.106: Unable to locate theme engine in module_path: "murrine",
...
First, find the running GUI environment from the terminal:
[mythcat@desk ~]$ echo $XDG_CURRENT_DESKTOP
X-Cinnamon
This allows us to know that the issue may be a GTK theme package.
[root@desk bin]# dnf install gtk-murrine-engine.x86_64
Last metadata expiration check: 0:45:00 ago on Mon 06 Jan 2020 11:14:27 AM EET.
Dependencies resolved.
...
Installed:
  gtk-murrine-engine-0.98.2-17.fc31.x86_64                                      

Complete!
Now the Android Studio works well without warning errors:
[mythcat@desk bin]$ ./studio.sh 
Jan 06, 2020 12:00:51 PM java.util.prefs.FileSystemPreferences$1 run
INFO: Created user preferences directory.
...

Saturday, January 4, 2020

Fedora 31 : Install MongoDB on Fedora 31 distro.

Today I will show you how to install the MongoDB on Fedora 31 distro. MongoDB is a general-purpose, document-based, distributed database built for modern application developers and for the cloud.
You can see the source code for MongoDb at the GitHub website.
First, you need to create a repository file.
[mythcat@desk ~]$ su
Password: 
[root@desk mythcat]# vi /etc/yum.repos.d/mongodb.repo
Add the code for this repository file.
[mongodb-org-4.2]
name=MongoDB Repository
baseurl=https://repo.mongodb.org/yum/redhat/8Server/mongodb-org/testing/x86_64/
gpgcheck=1
enabled=1
gpgkey=https://www.mongodb.org/static/pgp/server-4.2.asc
Let's search this Fedora apckage with dnf tool
[root@desk mythcat]# dnf search mongodb-org
MongoDB Repository                                        5.8 kB/s | 6.5 kB     00:01    
=========================== Name Exactly Matched: mongodb-org ============================
mongodb-org.x86_64 : MongoDB open source document-oriented database system (metapackage)
=============================== Name Matched: mongodb-org ================================
mongodb-org-shell.x86_64 : MongoDB shell client
mongodb-org-tools.x86_64 : MongoDB tools
mongodb-org-mongos.x86_64 : MongoDB sharded cluster query router
mongodb-org-server.x86_64 : MongoDB database server
[root@desk mythcat]# dnf install mongodb-org.x86_64 
Last metadata expiration check: 0:01:46 ago on Fri 03 Jan 2020 05:27:49 PM EET.
Dependencies resolved.
==========================================================================================
 Package                 Arch        Version                   Repository            Size
==========================================================================================
Installing:
 mongodb-org             x86_64      4.2.2-0.1.rc1.el8         mongodb-org-4.2       10 k
Installing dependencies:
 mongodb-org-mongos      x86_64      4.2.2-0.1.rc1.el8         mongodb-org-4.2       14 M
 mongodb-org-server      x86_64      4.2.2-0.1.rc1.el8         mongodb-org-4.2       25 M
 mongodb-org-shell       x86_64      4.2.2-0.1.rc1.el8         mongodb-org-4.2       17 M
 mongodb-org-tools       x86_64      4.2.2-0.1.rc1.el8         mongodb-org-4.2       47 M

Transaction Summary
==========================================================================================
Install  5 Packages

Total download size: 103 M
Installed size: 260 M
Is this ok [y/N]: y
...
 From       : https://www.mongodb.org/static/pgp/server-4.2.asc
Is this ok [y/N]: y
Key imported successfully
...
Installed:
  mongodb-org-4.2.2-0.1.rc1.el8.x86_64        mongodb-org-mongos-4.2.2-0.1.rc1.el8.x86_64
  mongodb-org-server-4.2.2-0.1.rc1.el8.x86_64 mongodb-org-shell-4.2.2-0.1.rc1.el8.x86_64 
  mongodb-org-tools-4.2.2-0.1.rc1.el8.x86_64 

Complete!
Start and enable MongoDB service to start on boot.
[root@desk mythcat]# systemctl start mongod
[root@desk mythcat]# sudo systemctl enable mongod
[root@desk mythcat]# systemctl status mongod
● mongod.service - MongoDB Database Server
   Loaded: loaded (/usr/lib/systemd/system/mongod.service; enabled; vendor preset: disabl>
   Active: active (running) since Fri 2020-01-03 17:32:36 EET; 17s ago
     Docs: https://docs.mongodb.org/manual
 Main PID: 9019 (mongod)
   Memory: 71.0M
      CPU: 890ms
   CGroup: /system.slice/mongod.service
           └─9019 /usr/bin/mongod -f /etc/mongod.conf

Jan 03 17:32:34 desk systemd[1]: Starting MongoDB Database Server...
Jan 03 17:32:34 desk mongod[9017]: about to fork child process, waiting until server is r>
Jan 03 17:32:34 desk mongod[9017]: forked process: 9019
Jan 03 17:32:36 desk mongod[9017]: child process started successfully, parent exiting
Jan 03 17:32:36 desk systemd[1]: Started MongoDB Database Server.
Jan 03 17:32:47 desk systemd[1]: /usr/lib/systemd/system/mongod.service:16: PIDFile= refe>
...
Use the netstat utility to confirm that indeed Mongod service is listening.
[root@desk mythcat]# netstat -pnltu | grep mongo
tcp        0      0 127.0.0.1:27017         0.0.0.0:*               LISTEN      9019/mongod
Create an admin user with elevated privileges to perform elevated tasks.
[root@desk mythcat]# mongo
MongoDB shell version v4.2.2-rc1
...
> use admin 
switched to db admin
> db.createUser(
...  {
...  user: "admin",
...  pwd: "123",
...  roles: [ { role: "userAdminAnyDatabase", db: "admin" } ]
...  }
...  )
Successfully added user: {
 "user" : "admin",
 "roles" : [
  {
   "role" : "userAdminAnyDatabase",
   "db" : "admin"
  }
 ]
}
Show the users:
> show users
{
 "_id" : "admin.admin",
 "userId" : UUID("5ca3a1c2-6225-4158-b2bc-e32e5e5de58f"),
 "user" : "admin",
 "db" : "admin",
 "roles" : [
  {
   "role" : "userAdminAnyDatabase",
   "db" : "admin"
  }
 ],
 "mechanisms" : [
  "SCRAM-SHA-1",
  "SCRAM-SHA-256"
 ]
}
To enable authentication edit the /lib/systemd/system/mongod.service file, under the [Service] section, locate and edit the Environment parameter as shown.
[root@desk mythcat]# vim /lib/systemd/system/mongod.service
...
[Unit]
Description=MongoDB Database Server
Documentation=https://docs.mongodb.org/manual
After=network.target

[Service]
User=mongod
Group=mongod
Environment="OPTIONS= --auth -f /etc/mongod.conf"
...
Apply the changes to the service mongo unit.
[root@desk mythcat]# systemctl daemon-reload
[root@desk mythcat]# systemctl restart mongod
[root@desk mythcat]# systemctl status mongod
● mongod.service - MongoDB Database Server
   Loaded: loaded (/usr/lib/systemd/system/mongod.service; enabled; vendor preset: disable>
   Active: active (running) since Fri 2020-01-03 17:44:09 EET; 11s ago
     Docs: https://docs.mongodb.org/manual
  Process: 9272 ExecStartPre=/usr/bin/mkdir -p /var/run/mongodb (code=exited, status=0/SUC>
  Process: 9273 ExecStartPre=/usr/bin/chown mongod:mongod /var/run/mongodb (code=exited, s>
  Process: 9274 ExecStartPre=/usr/bin/chmod 0755 /var/run/mongodb (code=exited, status=0/S>
  Process: 9275 ExecStart=/usr/bin/mongod $OPTIONS (code=exited, status=0/SUCCESS)
 Main PID: 9277 (mongod)
   Memory: 168.3M
      CPU: 1.423s
   CGroup: /system.slice/mongod.service
           └─9277 /usr/bin/mongod --auth -f /etc/mongod.conf
...

Friday, January 3, 2020

Fedora 31 : Test Google locally Apps Script CLI.

The Apps Script CLI, or clasp, is a tool that lets you create, edit, and deploy Apps Script projects locally like Sheets, Docs, Forms, and Slides.
[mythcat@desk ~]$ mkdir google
[mythcat@desk ~]$ cd google
[mythcat@desk google]$ sudo dnf install nodejs
[sudo] password for mythcat: 
Last metadata expiration check: 2:03:50 ago on Fri 03 Jan 2020 11:37:12 AM EET.
Dependencies resolved.
================================================================================
 Package          Arch        Version                        Repository    Size
================================================================================
Installing:
 nodejs           x86_64      1:12.13.1-1.fc31               updates      413 k
Installing dependencies:
 nodejs-libs      x86_64      1:12.13.1-1.fc31               updates       19 M
 npm              x86_64      1:6.12.1-1.12.13.1.1.fc31      updates      3.4 M
Installing weak dependencies:
 nodejs-docs      noarch      1:12.13.1-1.fc31               updates      2.4 M

Transaction Summary
================================================================================
Install  4 Packages

Total download size: 25 M
Installed size: 132 M
Is this ok [y/N]: y
...
Complete!
The clasp uses requires Node.js >= v6.0.0. Let's install it:
[mythcat@desk google]$ sudo npm install n -g
/usr/local/bin/n -> /usr/local/lib/node_modules/n/bin/n
+ n@6.1.3
added 1 package from 4 contributors in 0.705s
[mythcat@desk google]$ sudo n latest

  installing : node-v13.5.0
       mkdir : /usr/local/n/versions/node/13.5.0
       fetch : https://nodejs.org/dist/v13.5.0/node-v13.5.0-linux-x64.tar.gz
   installed : v13.5.0 (with npm 6.13.4)

Note: the node command changed location and the old location may be remembered in your 
current shell.
         old : /usr/bin/node
         new : /usr/local/bin/node
To reset the command location hash either start a new shell, or execute PATH="$PATH"
[mythcat@desk google]$ sudo npm i @google/clasp -g
/usr/local/bin/clasp -> /usr/local/lib/node_modules/@google/clasp/src/index.js
npm WARN inquirer-autocomplete-prompt@1.0.1 requires a peer of inquirer@^5.0.0 || 
^6.0.0 but none is installed. You must install peer dependencies yourself.

+ @google/clasp@2.3.0
added 191 packages from 118 contributors in 53.457s 
The simple run of clasp command shows us all arguments:
[mythcat@desk google]$ clasp
Usage: clasp  [options]

clasp - The Apps Script CLI

Options:
  -v, --version                               
  -h, --help                                  output usage information

Commands:
  login [options]                             Log in to script.google.com
  logout                                      Log out
  create [options]                            Create a script
  clone [options] [scriptId] [versionNumber]  Clone a project
  pull [options]                              Fetch a remote project
  push [options]                              Update the remote project
  status [options]                            Lists files that will be pushed by clasp
  open [options] [scriptId]                   Open a script
  deployments                                 List deployment ids of a script
  deploy [options]                            Deploy a project
  undeploy [options] [deploymentId]           Undeploy a deployment of a project
  version [description]                       Creates an immutable version of the script
  versions                                    List versions of a script
  list                                        List App Scripts projects
  logs [options]                              Shows the StackDriver logs
  run [options] [functionName]                Run a function in your Apps Scripts project
  apis [options]                              List, enable, or disable APIs
    list
    enable 
    disable 
  help                                        Display help
  setting|settings [settingKey] [newValue]    Update  in .clasp.json
  *                                           Any other command is not supported
You can log in with this command
[mythcat@desk google]$ clasp login
Logging in globally...
...
This will open a webpage for authentification and ends with this text message: Logged in! You may close this page.
Now you can create a new folder for your project named clasp_code.
Use this command and arrows key to select the type of the project:
[mythcat@desk clasp_code]$ clasp create --title "my first project with clasp";
? Create which script? (Use arrow keys)
❯ standalone 
  docs 
  sheets 
  slides 
  forms 
  webapp 
  api 
...
User has not enabled the Apps Script API. Enable it by visiting 
https://script.google.com/home/usersettings then retry. 
If you enabled this API recently, wait a few minutes for the action to propagate 
to our systems and retry.
Open the URL to activate the API and run the command again to get the JSON file named appsscript.json.
You can clone an old project by script_ID.
Use this command into a new folder with the script_ID value from project menu File -> Project properties -> Info -> Script ID.
This will download the project in your current directory.
clasp clone script_ID 
To edit your project use this command:
[mythcat@desk clasp_code]$ clasp open
The next step is to pull and push operations:
[mythcat@desk clasp_code]$ clasp pull
Warning: files in subfolder are not accounted for unless you set a '.claspignore' file.
Cloned 2 files.
└─ appsscript.json
└─ Code.js
[mythcat@desk clasp_code]$ clasp push
└─ Code.js
└─ appsscript.json
Pushed 2 files.
The clasp allows you to manage versions and deployments with these commands:
[mythcat@desk clasp_code]$ clasp version "First version"
Created version 1.
[mythcat@desk clasp_code]$ clasp deploy 1 "First deployment"
Created version 2.
For more information see the GitHub webpage.