Subuser - Securing the Linux desktop with Docker

Visit us at subuser.org

As free software developers we like to share. We surf the web and discover new code. We are eager to try it out. We live out an orgy of love and trust, unafraid that some code we cloned from Git might be faulty or malicious. We live in the 60s, carefree hippies.

This is utopia.

But sharing code isn't safe. Every time we try out some stranger's script, we put ourselves at risk. Despite the occasional claim that Linux is a secure operating system, haphazardly sharing programs is NOT secure.

Furthermore, the fragmentation of the Linux desktop means that packaging work is needlessly repeated. Programs that build and run on Fedora must be repackaged for Ubuntu.

Subuser with Docker attacks both problems simultaneously. Docker provides an isolated and consistent environment for your programs to run in. Subuser gives your desktop programs access to the resources they need in order to function normally.

Subuser turns Docker containers into normal Linux programs:

Right now I'm editing this file in vim. vim is not installed on my computer though. It is installed in a docker container. However, in order to edit this file, all I had to do was type:

$ vim README.md

Subuser turns a docker container into a normal program. But this program is not fully privileged. It can only access the directory from which it was called, not my entire home dir. Each subuser is assigned a specific set of permissions, just like in Android. You can see an example permissions.json file bellow.

{
  "description"                : "A web browser."
  ,"maintainer"                : "Timothy Hobbs <timothyhobbs (at) seznam dot cz>"
  ,"executable"                : "/usr/bin/firefox"
  ,"user-dirs"                 : [ "Downloads"]
  ,"gui"                       : {"clipboard":true,"cursors":true}
  ,"sound-card"                : true
  ,"allow-network-access"      : true
}

For a list of all permissions supported by subuser, please see the subuser standard.

Installation

System Requirements

• Docker 1.3 or higher
• Python >= 3
• Git
• X11 and the xauth utility (You almost certainly have this)
• sudo (if you don't want to become a member of the docker group)

OS Requirements

• Linux: Everything supported
• OSX with docker for desktop: Limited support
  • inherit-timezone is ignored
  • xpra (graphical apps) doesnt work
  • Probaly other issues

Install with pip3: Stable version

1. Add yourself to the sudo group (or the docker group).

$ sudo nano /etc/group

Find sudo and add your username to the end of the line.

2. Install subuser from pip3.

$ sudo pip3 install subuser

3. Add ~/.subuser/bin to your path by adding the line PATH=$HOME/.subuser/bin:$PATH to the end of your .bashrc file.
4. Log out and then back in again.
5. Done!

Install from git: Development version

1. Add yourself to the sudo group (this is not necesary if you are already a member of the docker group).
2. Download the subuser repository

$ cd
$ git clone https://github.com/subuser-security/subuser

3. Add subuser/logic and ~/.subuser/bin to your path by adding the line PATH=$HOME/subuser/logic:$HOME/.subuser/bin:$PATH to the end of your .bashrc file.

Note

You will need to change the path to subuser/logic to refer to the location to which you downloaded subuser.

4. Log out and then back in again.
5. Done!

To learn more and read the full manual please visit subuser.org