https://github.com/zalando/python-nsenter
Enter kernel namespaces from Python
https://github.com/zalando/python-nsenter
docker linux-kernel namespaces nsenter python
Last synced: 3 months ago
JSON representation
Enter kernel namespaces from Python
- Host: GitHub
- URL: https://github.com/zalando/python-nsenter
- Owner: zalando
- License: other
- Archived: true
- Created: 2014-09-15T11:35:23.000Z (over 11 years ago)
- Default Branch: master
- Last Pushed: 2020-03-27T16:18:56.000Z (over 5 years ago)
- Last Synced: 2025-09-17T01:19:36.730Z (3 months ago)
- Topics: docker, linux-kernel, namespaces, nsenter, python
- Language: Python
- Homepage: https://pypi.python.org/pypi/nsenter
- Size: 29.3 KB
- Stars: 141
- Watchers: 43
- Forks: 20
- Open Issues: 5
-
Metadata Files:
- Readme: README.rst
- Contributing: CONTRIBUTING.rst
- License: LICENSE
Awesome Lists containing this project
- awesome-linux-containers - python-nsenter
README
=======
NSEnter
=======
.. image:: https://travis-ci.org/zalando/python-nsenter.svg?branch=master
:target: https://travis-ci.org/zalando/python-nsenter
:alt: Travis CI build status
**NSEnter** is a Python package that enables you to enter Linux kernel namespaces — mount, IPC, net, PID, user and UTS — with a single, simple "setns" syscall. The command line interface is similar to the nsenter_ C program.
Project Origins
---------------
When working with Docker_ containers, questions usually arise about how to connect into a running container without starting an explicit SSH daemon (`which is considered a bad idea`_). One way is to use Linux Kernel namespaces, which Docker uses to restrict the view from within containers.
The ``util-linux`` package provides the ``nsenter`` command line utility, but `Ubuntu 16.04 LTS`_ unfortunately does not. Jérôme Petazzoni provides a `Docker recipe`_ for ``nsenter`` on GitHub, or you can compile ``nsenter`` `from source`_. As there is only one simple syscall to enter a namespace, we can do the call directly from within Python using the ``ctypes`` module. We bundled this syscall to create NSEnter.
Additional Links
````````````````
- "Entering Kernel Namespaces from Python," Zalando Tech `blog post`_
- On PyPi_
Requirements
````````````
- Python 2.6 or higher
Installation
````````````
From PyPI::
sudo pip3 install nsenter
From git source::
python3 setup.py install
Usage
`````
Example of command line usage::
docker run -d --name=redis -t redis
sudo nsenter --all --target=`docker inspect --format '{{ .State.Pid }}' redis` /bin/bash
Example of usage from Python:
.. code:: python
import subprocess
from nsenter import Namespace
with Namespace(mypid, 'net'):
# output network interfaces as seen from within the mypid's net NS:
subprocess.check_output(['ip', 'a'])
# or enter an arbitrary namespace:
with Namespace('/var/run/netns/foo', 'net'):
# output network interfaces as seen from within the net NS "foo":
subprocess.check_output(['ip', 'a'])
Development Status
``````````````````
This project works as-is. There are currently no plans to extend it, but if you have an idea please submit an Issue to the maintainers.
License
-------
See file_.
.. _Docker: https://www.docker.com/
.. _which is considered a bad idea: https://jpetazzo.github.io/2014/06/23/docker-ssh-considered-evil/
.. _Ubuntu 16.04 LTS: https://askubuntu.com/questions/439056/why-there-is-no-nsenter-in-util-linux
.. _Docker recipe: https://github.com/jpetazzo/nsenter
.. _from source: https://askubuntu.com/questions/439056/why-there-is-no-nsenter-in-util-linux
.. _nsenter: http://man7.org/linux/man-pages/man1/nsenter.1.html
.. _blog post: http://tech.zalando.com/posts/entering-kernel-namespaces-with-python.html
.. _PyPi: https://pypi.python.org/pypi/nsenter
.. _file: https://github.com/zalando/python-nsenter/blob/master/LICENSE