rDocker

Securely control a remote docker daemon CLI using ssh forwarding, no SSL setup needed.

##Install

If you want it available on your system run the following (you may need elevated privileges for this to work):

curl -L https://github.com/dvddarias/rdocker/raw/master/rdocker.sh > /usr/local/bin/rdocker
chmod +x /usr/local/bin/rdocker

If you just want it lying around on your file system:

git clone https://github.com/dvddarias/rdocker.git
cd rdocker

##Usage

Lets assume you want to control the docker daemon on your webserver.com server from your local machine. You just run:

rdocker [email protected]

This will open a new bash session with a new DOCKER_HOST variable setup. Any docker command you execute will take place on the remote docker daemon. To test the connection run:

docker info

Check the Name: field it should have the remote hostname .... That's it!!!

You could for example run docker build to build an image on the remote host and then docker save -o myimage.tar image_name to store it locally. Or run docker exec -it container_name bash to open a shell session on a remote container. Even bash auto-completion works ok.

You can choose the local port the docker daemon will be forwarded to by passing it as the last argument:

rdocker [email protected] 9000

You can also interact with the remote daemon from any other terminal by using the -H parameter of the docker client:

docker -H localhost:9000 images

To stop controlling the remote daemon and close the ssh forwarding, just exit the newly created bash session (press Ctrl+D).

##Dependencies & Configuration

Basically None. If you can login to your server over ssh and run docker commands this script should work out of the box.

Just remember:

• The user you log in with should have permissions access the /var/run/docker.sock otherwise you will get a lot of: An error occurred trying to connect.... To solve this add the user to the docker group.
• It uses ssh to connect to the host so you should also have the the appropriate permissions (private-key, password, etc..).
• On the remote host it uses: python(2/3), bash, and ssh but these are already installed on most linux distributions.
• Needless to say you need docker installed on both computers ;).

##How does it work

This is a general overview of how it works, feel free to check the script for further details:

1. Connects over ssh to the remote host, finds a free port on both computers, and opens ssh forwarding
2. Runs over the ssh connection a python script that forwards connections on the remote host from localhost:remote_port to the unix domain socket at /var/run/docker.sock
3. Starts a new bash session with DOCKER_HOST environment variable set to tcp://localhost:local_port
4. On session exit it SIGTERMs the ssh connection.

Tested on Ubuntu, Mint and Debian. It should work on any linux based OS. I don't have a Mac around to test it :(. Contributions are of course welcome.