About

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

wiki
Goals
Requirements
Building
Try It
Getting Your Feet Wet with the procszoo Module
Networks
Docs
Known Issues
Exported Functions and Objects
Test Platforms

Goals

Procszoo aims to provide you a simple but complete tool and you can use it as a DSL or an embeded 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.

Requirements

Procszoo only requires Python standard libraries and the following packages

# on RHEL/CentOS >= 6
sudo yum -y install autoconf gcc make glibc-headers
# Debain/Ubuntu
sudo apt-get -y install autoconf gcc make libc6-dev

On the RHEL/CentOS/Scientific Linux >= 6, because of SELinux causing some libffi bug, if you try python3, please disable SELinux as follows,

sudo sed -i -e 's/^SELINUX.*=.*/SELINUX=disabled/g' /etc/selinux/config
sudo reboot

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}

Building

All you need do are to clone it and do as follows,

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

Try It

Now you can try it in an interactive shell as follows

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

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 sth that we are in namespaces

programs get samll pids, 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 our namespaces
```
  ls -l /proc/self/ns
```
if the kernel support and enable "user" namespaces, we are superuser now
```
  id
```
if you have trouble to try the above steps, please reference Known Issues.

Getting Your Feet Wet with the procszoo module

First, make sure that the procszoo module path in the sys.path. You can add the path as follows

import sys
sys.path.append(path_to_procszoo)

then if you want to enable each namespaces that your kernel supports

from procszoo.c_functions import *

if __name__ == "__main__":
    spawn_namespaces()

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

from procszoo.c_functionss import *

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

Networks

Let's add network to the new namespaces.

Because we will mount namespaces entries by the bind flag, we need 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 it to the new namespace in a new terminal
```
  sudo ip link add veth0 type veth peer name veth1
  sudo ip link set dev veth1 netns ns
```

in the 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
```

Docs

Known Issues

os.execv complains "permission deny"

If running richard_parker failed on RHEL/CentOS/Fedora, and get following error message like this
```
    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 pls reference here

Exported Functions and Objects

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

objects
- workbench
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
- 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

Test Platforms

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)

azhuzhu / procszoo

About

Contents

Goals

Requirements

Building

Try It

Getting Your Feet Wet with the procszoo module

Networks

Docs

Known Issues

Exported Functions and Objects

Test Platforms

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