docker-config

New/experimental

Docker image for editing configuration exported from another container. Currently supported:

• SSH
• Git
• Vim

The image is intended to be useful enough already, but you'll probably want to extend it. Also, it is primarily intended as a development tool for working with new Docker images. You still need a strategy to launch new docker containers based on the finished configuration.

Usage

The image you want to configure should already be running and exporting volumes for the necessary config directories.

Run an instance of the config container:

docker run -d \
    -p <port>:22 \
    -e SSH_AUTHORIZED_KEY=`cat <public-key>` \
    --volumes-from <container-id> \
    fazy/config

Change <...> as follows:

• <port> = SSH port on the host to listen on
• <public-key> = SSH public key to allow login inside the container, e.g. ~/.ssh/id_rsa.pub
• <container-id> = id/name of the container exporting volumes that you want to edit

SSH into your container:

ssh -p <port> root@localhost

After editing the config, you might need to restart the application within the container. This is entirely dependant on the application however.

SSH config

The container requires a public key for SSH access, and also supports adding a private key for outbound connections.

• SSH_AUTHORIZED_KEY - key that will be written to /root/.ssh/authorized_keys inside the container

• SSH_PRIVATE_KEY - key that will be written to /root/.ssh/id_rsa inside the container (place the corresponding public key with hosts you want to connect to, e.g. Github)

Git config

You can configure the following:

• GIT_AUTHOR_NAME
• GIT_AUTHOR_EMAIL

There's also a .gitconfig file non-user specific which can be changed by building a new container with your own .gitocnfig.

How to launch the container via Fig

If you are using Fig to manage Docker, here's an example fig.yml:

config:
    image: fazy/config
    environment:
        SSH_AUTHORIZED_KEY:
        SSH_PRIVATE_KEY:
        GIT_AUTHOR_NAME: My Name
        GIT_AUTHOR_EMAIL: me@example.net
    volumes_from:
        - my_docker_application
    ports:
        - "2222:22"

I didn't want to include my SSH keys in fig.yml, so I launch fig like this:

cd /path/to/fig/config
SSH_AUTHORIZED_KEY=`cat ~/.ssh/id_rsa.pub` SSH_PRIVATE_KEY=`cat ~/.ssh/id_rsa` fig up -d

Todo

This Dockerfile is barely started, here are a few TODOs:

• Allow for Git configuration
• Allow for Vim configuration
• Allow key-based SSH login
• Script that starts a new config instance, connects via SSH, then terminates the config instance after exiting SSH (handy for quick config edits without leaving config containers lying around).