Knife Docker

Description

knife-docker makes it easy to test your Chef cookbooks against a clean system. It is a [knife] (http://docs.opscode.com/knife.html) plugin to create and delete [Docker] (http://docker.io) containers managed by Chef.

Used together with [chef-zero] (https://github.com/opscode/chef-zero), knife-docker is a great way to get started with Chef.

Installation

Make sure you are running Chef, which can be installed via:

gem install chef

This plugin is distributed as a Ruby Gem. To install it, run:

gem install knife-docker

Depending on your system's configuration, you may need to run this command with root/administrator privileges.

Prerequisites

You need to be able to create/list/stop Docker containers. Please see [the Docker documentation] (https://www.docker.io/gettingstarted/) for more information.

knife-docker bootstraps your Docker containers via SSH. Thus, you need to use a Docker image with the SSH daemon installed and your public key in root's authorized_keys. The easiest way to ensure this prerequisite is met is using [the Dockerfile we provide] (https://github.com/ema/knife-docker/blob/master/Dockerfile). You should modify it to make sure your SSH public key is included in the resulting image.

# Add your SSH key to Dockerfile
$ vim Dockerfile

# Build a Docker container image called 'knife-docker-debian'
$ docker build -t knife-docker-debian .

Examples

  # Create and bootstrap a Debian container over ssh
  $ knife docker create -I knife-docker-debian

  # If using boot2docker (i.e. running docker + knife under os x)
  $ knife docker create -I knife-docker-debian -b

  # Create a Debian container, bootstrap it, and apply the specified roles/recipes
  $ knife docker create -I knife-docker-debian -r 'recipe[postgresql::server]'

  # Delete a container with id 3ebc494961fa and purge it from the Chef server
  $ knife docker delete 3ebc494961fa --purge

Use the --help option to read more about each subcommand. Eg:

knife docker create --help