switchns

README

geard-switchns

Utility command which switches into a specified docker container's namespace and execute a command. It allows two use-cases:

• Admin commands

Usage:

switchns --container=<container name> [--env="key=value"]... [--] <command>...

Examples:

switchns --container=gear-0001 -- /bin/echo 1
switchns --container=gear-0001 -- /bin/bash -c "echo \$PATH"
switchns --container=gear-0001 --env="FOO=BAR" --env="BAZ=ZAB" -- /bin/bash \
  -c "echo \$FOO \$BAZ"

Allows a user with CAP_SYS_ADMIN capability to switch into a specified docker container and execute a command. Typical use for this would be to run admin commands within a container.

• User SSH

Add geard-switchns as a command to the .authorized_keys file. Eg:

command="/usr/sbin/switchns" ssh-rsa AAAA...== user@host

When the user SSH's into the host machine, SSH runs geard-switchns. The utility then looks up a docker container with the same name as the username and starts a bash shell within the container.

License

Apache Software License (ASL) 2.0.

Documentation

Overview

The switchns binary - an executable for executing a process inside a running Docker container. Can be used as root to switch into any named container (name is the same as the gear name), or as a container user (user tied to a container) to enter the context for SSH or other function. Will be eventually become a setuid stub for docker exec.