Author: meets2tarun

This author has written 33 articles

Customizing Chromium for the Meilix Generator

Imagine if you are able to vanish that star icon of the bookmark which is on the extreme right of address bar. Disable auto-fill option, disable some particular extension to get install and many more things. And you could even distribute it to any friend to get the same setting within just copy and paste. We are working on such features for the FOSSASIA Meilix generator for Chromium.

Chromium is one of the most popular browsers. But had you ever thought how grateful it would be if you are able to customize your chromium to a larger extent? Sometimes it feels that few features are there which we merely used.

So here it is the way to tailor cut the specification of the browser and you can even give it to your friend to try out the feature. It just needs to copy and paste a file for your friend. Not forget to mention from where do I get this file: fossasia/meilix

How can you do that?

This gist is a .json file which has to be copied in the etc/chromium-browser/policies/managed with the name chrome.json. That’s it.

Chrome.json
It’s a policy template of Linux for the browser Chromium. This file contains different policies and they are commented. Uncomment the required values and set your desired values.

Format of the policy of the JSON file.

Each policy is well-structured so that a person can easily understand and change its values.

Let’s take an example:

1 // Enable Bookmark Bar
2 //-------------------------------------------------------------------------
3 // Enables the bookmark bar on Google Chrome.  If you enable this setting,
4 // Google Chrome will show a bookmark bar.  If you disable this setting, users
5 // will never see the bookmark bar.  If you enable or disable this setting,
6 // users cannot change or override it in Google Chrome.  If this setting is
7 // left not set the user can decide to use this function or not.
8 //"BookmarkBarEnabled": true,

This is an example of controlling of bookmark bar which is mention on line 1
Line 2 is left intentionally for proper formatting
Line 3-7 explains the purpose of the policy, it explains itself quite briefly
Line 8 is the by default set option, to alter it, uncomment it and reverse the values.

This same way is being followed throughout. There are many other options which act as a boon.

Edit the file and share it with your friends and ask them to copy it in the same location and then they can also get the benefit of the feature.

Continue ReadingCustomizing Chromium for the Meilix Generator

Building Metapackages to Customize the Meilix Linux Distro Generator

This article will guide you to build a metapackage with your required configuration and to use it inside the meilix distro to customize and use the inbuild metapackages to customize the configuration file of packages and properties of various browsers.
Metapackages are scripts which contain the link to existing packages. It’s a .deb file. As packages include dependencies analogically metapackages include packages. So, we can say that metapackages do not contain actual software, they depend upon packages. This guide will help you to make your own metapackage easily, configure it and distribute it among your friends and other Linux users.

How to get started to build a metapackage for meilix?

At first one needs to sort out the metapackages that it needs to be there in the metapackages. One can also come up with the package which he don’t want to install but that comes under dependency of the some package.
It’s easy, a few lines of commands and you will have a .deb metapackage in your hand.
We will use equivs as a tool to build metapackages.

Install equivs :

sudo apt-get install equivs

equivs-control ns-control

This will create a file with the name ns-control and that files looks similar to this:

1.### Commented entries have reasonable defaults.
2.### Uncomment to edit them.
3.# Source: <source package name; defaults to package name>
4.Section: misc
5.Priority: optional
6.# Homepage: <enter URL here; no default>
7.Standards-Version: 3.9.2
8.Package: <package name; defaults to equivs-dummy>
9.# Version: <enter version here; defaults to 1.0>
10.# Maintainer: Your Name <yourname@example.com>
11.# Pre-Depends: <comma-separated list of packages>
12.# Depends: <comma-separated list of packages>
13.# Recommends: <comma-separated list of packages>
14.# Suggests: <comma-separated list of packages>
15.# Provides: <comma-separated list of packages>
16.# Replaces: <comma-separated list of packages>
17.# Architecture: all
18.# Multi-Arch: <one of: foreign|same|allowed>
19.# Copyright: <copyright file; defaults to GPL2>
20.# Changelog: <changelog file; defaults to a generic changelog>
21.# Readme: <README.Debian file; defaults to a generic one>
22.# Extra-Files: <comma-separated list of additional files for the doc directory>
23.# Files: <pair of space-separated paths; First is file to include, second is destination>
24.# <more pairs, if there's more than one file to include. Notice the starting space>
25.Description: <short description; defaults to some wise words>
long description and info

second paragraph

 

Now the question is what to do with this:
Line 3-7 : the control information of the source packages.
Line 8-25 : the control information for the binary packages
Source packages are those packages which contain the source code of the package. One can compile the source and install it in any architecture of the machine .
Binary packages are those packages which are specific to the architecture of machine. And one can easily install it with a click.

Description of important lines:
Line 3: The name of the source package, same to Line 8
Line 4: section of the distribution
There are various categories in which a source package can be put into.
Line 9: version of the package, it is helpful if you want it install packages of a particular version
Line 11: you have to write the dependencies of the packages #better remain this commented
Line 12 : Include the name of the packages that you want to include in the metapackage
Line 17: Architecture is set to all that is for both 32 and 64 bit.
Line 25: Provide description

Next is what
Then after filling up the text file, now it’s time to build it.

Build the package:

equivs-build ns-control

Now it will run and will give you a .deb file.
dpkg –i *.deb will install the deb file.

This is the metapackage which contains the packages which you have included.
I have used this wiki as a source for the required information.

Suppose one of most popular metapackage : gnome-desktop-environment – It is the a desktop environment gnome flavoured. It gives the graphical user interface to the user with popular email, office tools, music and other wide range of applications.

How a common Linux user can get the benefit of it?

We know that most of the people avoid Linux because of its beautiful command line feature. They just want to use mouse/touchpad throughout.
With the help of this, a person can build a metapackage. This one can distribute to its friend and can also use for the future purpose.
One can also use this to make a collection of metapackages of different packages like hacking tools, text tools, etc.

How we uses the metapackages?

Meilix script uses the metapackages for building of all the required packages. In our webapp version (meilix-generator) we made several metapackages that will be asked from the user and a user can choose one among them according to its requirement. It will also contain the information that which packages the metapackage is made of.

Suppose event metapackages include the packages needed by the people for the events purpose which will predefined by us and they will consist of lightweight text editor, media player, document viewer etc. In an education related metapackage one contain packages related to school, workshop.

Now meilix repo contains its own metapackages that it uses to contain the distro.

How meilix metapackage is used to control distro configuration?

We can even control the distro properties including the browser configuration, it’s startup page, search page and many more things through metapackages. Let’s see how:

We created a metapackage with the name meilix-default-settings and used it to config various features in the distro. The meilix settings metapackage consists of etc folder where we can made the changes to get it on the distro. We can even include property folder in the .config under skel folder to copy the changes into the home folder of the new user. To change the chrome configuration, we need to edit the chrome.json file. To change firefox configuration we need to edit prefs.js file.

The metapackage folder is: https://github.com/fossasia/meilix/tree/master/meilix-default-settings

Repository using metapackages

https://github.com/fossasia/meilix
https://github.com/fossasia/meilix-generator  (the webapp)

Continue ReadingBuilding Metapackages to Customize the Meilix Linux Distro Generator

Meilix System Lock

Meilix-Systemlock has to two main shell files: lock.sh and unlock.sh. The purpose of the script is that if the lock.sh is called, the content inside the home directory will be reset after rebooting of the system. And it will be in that state of getting back reset to home directory until unlock.sh is being called.

An Example to illustrate

Suppose in a computer lab, the students are given computers and they make changes which don’t seem convenient to the maintainer of the lab. The maintainer freezes the system to have a clean state, and the students use the computer and make it “dirty”, and the reboot restores to the clean state when maintainer running freeze. As soon as the lock.sh is being called system will copy the files in the home directory to another place, then reboot. Reboot and copying don’t occur parallelly.

The system remains in the frozen state and every time when its get rebooted, it gets to the same state of home directory when it is being frozen. This can be stopped by calling unlock.sh. This can be helpful for the maintainer for creating a new freeze point.
I get the idea through chat with Yeo Wei and used the logo from here.

Diagram for clear representation

How does it solve someone’s problem in daily life?

As I explained in the example, it can easily solve the problem of a computer lab assistant at a school, college, public cafe, etc. I request this idea should reach to them, and they can run the lock.sh to freeze the system so as to avoid the dirtiness made by a third person. Maintainer generally left out this dirt for next user who is going to work on the same PC. But this technique will make the PC new and new user doesn’t have to clean the dirt made by the previous user and they can setup their environment freshly.

Understanding the Important Code Mechanism:

In the lock.sh script

Line: 44

echo “sudo rsync -a –delete /etc/.ofris/$ofris_user/ /home/$ofris_user/” >> ofris_tmp

– this line restore the files stored in /etc/.ofris/user to /home/user” into /etc/rc.local (which runs every time computer boots).

Line: 38, 39

if [ $ofris_rst = 1 ]; then 
echo "Error: The system has been locked, please select the fourth choice to unfreeze the system..."

– this line stops the execution of lock.sh if it hasn’t been unlocked yet.

In the unlock.sh script

Line: 1

grep -v "sudo rsync -a --delete /etc/" /etc/rc.local > ofris_tmp_b

– this check if the rc.local is being modified or not.
And rest command removes the created folder and restore the home folder to its original state.

The important repository containing:
https://github.com/fossasia/meilix-systemlock

Continue ReadingMeilix System Lock