Procszoo is a small Python module that gives you full power to manage your processes by Linux namespaces.

• Wiki
• Goals
• Resources
• Requirements
• Install
• Building
• Try It
• Getting Your Feet Wet with the procszoo Module
• Networks
• Docs
• Known Issues
• Exported Functions, Objects, and Helpful CLI
• Test Platforms

Procszoo aims to provide you a simple but complete tool and you can use it as a DSL or an embedded programming language which let you operate Linux namespaces by Python.

Procszoo gives a smart init program. I get it from baseimage-docker. Thanks a lot, you guys.

Procszoo does not require new version Python (but we support python3, too) and Linux kernel.

• IRC channel: #procszoo on freenode.net

Procszoo only requires Python standard libraries and the following packages

# if you want python3, please install following package's python3 version
# on RHEL/CentOS >= 6
sudo yum -y install autoconf gcc make glibc-headers
sudo yum -y install python-devel python-setuptools
# Debain/Ubuntu
sudo apt-get -y install autoconf gcc make libc6-dev
sudo apt-get -y install python-dev python-setuptools

1. You can install the procszoo by setuptools

    git clone https://github.com/xning/procszoo.git
    cd procszoo && sudo ./setup.py install
   

2. You can install the procszoo by pip

    sudo pip install procszoo
   

If you don't want to install it, then you can just clone it and do as the following commands,

git clone https://github.com/xning/procszoo.git
cd procszoo && make

By default, the above commands will build the program for your default Python version. If you want to build it for other Python version, just specify your desired Python interpretor through the PYTHON variable of the make command. Eg. To build for Python 3:

make PYTHON=/usr/bin/python3

If you will clone the procszoo in your home directory, On the RHEL/CentOS/Scientific Linux/Fedora, the default mode of your home directory is 0400, this will cause trouble, hence change it

chmod go+rx ${HOME}

Now you can try it in an interactive shell as follows (we suppose you have installed the procszoo)

richard_parker -l                       # what namsepaces are available?
richard_parker --available-c-functions  # what C functions are available?
richard_parker                          # get an interactive shell

If your Linux kernel doesn't support "user" namespaces, e.g., RHEL6/CentOS6, RHEL7/CentOS7, you need super user privileges

sudo richard_parker

And now, you can check things that we have in namespaces

• programs get small pid number, e.g., 1, 2, etc., and there is only lo device and it is down

    ps -ef 
    ifconfig -a
  

• open another terminal, we can see that the namespaces entries are different from last namespaces

    ls -l /proc/self/ns
  

• if the kernel support and enable "user" namespaces, we are superuser at the same time

    id
  

• if you have trouble to try the above steps, please refer to Known Issues.

If you want to enable each namespace that your kernel supports

from procszoo.c_functions import *

if __name__ == "__main__":
    spawn_namespaces()

If you need to run your own program instead of an interactive shell,

from procszoo.c_functionss import *

if __name__ == "__main__":
    spawn_namespaces(nscmd=path_to_your_program)

Let's add network function to the new namespaces.

Because we will mount namespaces entries by the bind flag, we have to run richard_parker as the super user.

Except the shell that richard_parker will open, we need another interactive shell to make veth devices and add them to the new "net" namespace.

• create a mount point

    mkdir /tmp/ns
  

• create namespaces

    sudo richard_parker --ns-bind-dir=/tmp/ns
  

• in richard_parker, configure the lo device

    ip link set lo up
  

• in a new terminal, remount the /tmp/ns/net to /var/run/netns/net so ip command could operate it

    [ -d /var/run/netns ] | sudo mkdir -p  /var/run/netns
    sudo touch /var/run/netns/ns
    sudo mount --bind /tmp/ns/net /var/run/netns/ns
  

• in the new terminal, create two devices and set one of them to the new namespace in this new terminal

    sudo ip link add veth0 type veth peer name veth1
    sudo ip link set dev veth1 netns ns
  

• in this new terminal, configure veth0 device

    sudo ip link set veth0 up
    sudo ip addr add 192.168.0.10/24 broadcast 192.168.0.255 dev veth0
  

• in richard_parker, configure veth1

    ip link set veth1 up
    ip addr add 192.168.0.11/24 broadcast 192.168.0.255 dev veth1
  

• let's say "hello" from the new terminal

    ping -c 3 192.168.0.11
  

• let's say "hello" from richard_parker

    ping -c 3 192.168.0.10
  

• namespaces(7)

• unshare(2)

• setns(2)

• ip(8)

• mount(2)

• pivot_root(2)

• Linux namespaces

• Docker and the PID 1 zombie reaping problem

• Resource management:Linux kernel Namespaces and cgroups

• Containers and Namespaces in the Linux Kernel

• os.execv complains "permission deny"

  If running richard_parker unsuccessfully on RHEL/CentOS/Fedora, and get the following error messages like those

      os.execv(...)
  OSError: [Errno 13] Permission denied
  

  That's not a bug, please see the comment.

• "ip netns" failed on RHRL6/CentOS6 and gave error messages as follows

  Object "nets" is unknown, try "ip help".
  

  We need a more latest iproute package, to do that please refer to here

The procszoo.utils exported following functions and objects, and I don't think that you need learn them all

• objects

  • workbench
  • SpawnNamespacesConfig

• key functions

  • spawn_namespaces
  • check_namespaces_available_status

• helpful functions

  • atfork
  • sched_getcpu
  • mount
  • umount
  • umount2
  • unshare
  • setns
  • gethostname
  • sethostname
  • getdomainname
  • setdomainname
  • pivot_root
  • to_unicode
  • to_bytes
  • adjust_namespaces
  • get_namespace
  • get_available_propagations
  • get_current_users_and_groups
  • getresuid
  • getresgid
  • setresuid
  • setresgid
  • show_namespaces_status
  • show_available_c_functions
  • cgroup_namespace_available
  • ipc_namespace_available
  • net_namespace_available
  • mount_namespace_available
  • pid_namespace_available
  • user_namespace_available
  • uts_namespace_available
  • unregister_fork_handlers

• Exceptions

  • CFunctionBaseException
  • CFunctionNotFound
  • NamespaceGenericException
  • UnknownNamespaceFound
  • UnavailableNamespaceFound
  • NamespaceSettingError

• Helpful CLI

  • richard_parker
  • mamaji

I test the richard_parker and these scripts in tests/ on following archs

• CentOS 6(x86)
• CentOS 7(x86_64)
• Fedora 24(x86_64)
• ubuntu 12.04(armv7l)
• Ubuntu 14.04(x86_64)
• Ubuntu 16.04(x86_64)
• openSUSE 42(x86_64)