docker-centos-openssh

A CentOS 7 container that runs openssh server.

You can use this container to quickly startup a "machine" and test things, or it can be used as an SSH server, maybe a stepstone.

This container will generate new keys (host and user) at startup if none are loaded by attaching a volume.

Running the container.

It's quite easy to start a container:

docker run -P robertdebock/docker-centos-openssh

A private key will be displayed, copy-pasts-save it, set the permissions to 0600.

Find out what port Docker has connected to the container:

docker port docker-centos-openssh

And connect to the container:

ssh -p ${port} -i ${savedkey} root@${ip}

The ${ip} depends on where the container is running.

Using your own private key

Simply save your key in a folder like "dot-ssh" and map the volumes:

docker run -P -v $(pwd)/./ssh:/root/.ssh/ robertdebock/docker-centos-openssh

Using with docker-compose

You may setup a testlab, for example for Ansible or Rundeck, using Docker-compose, like so:

version: '3'
services:
  server:
    image: robertdebock/docker-centos-openssh
    volumes:
      - /path/to/dot-ssh:/root/.ssh/
    links:
      - client1
      - client2
      - client3
    ports:
      - "2222:22"
  client1:
    image: robertdebock/docker-centos-openssh
    volumes:
      - /path/to/dot-ssh:/root/.ssh/
  client2:
    image: robertdebock/docker-centos-openssh
    volumes:
      - /path/to/dot-ssh:/root/.ssh/
  client3:
    image: robertdebock/docker-centos-openssh
    volumes:
      - /path/to/dot-ssh:/root/.ssh/

Technologies used to build and test

Travis CI is used to build, run and test the image. Docker Hub is used to deploy the image to. This (building on Travis CI and publishing to Docker Hub) happens in parallel. On Travis CI, few project are used:

• Bats for testing.
• Docker Lint for finding weird errors.

A bit weird about this setup is that when the build fails, an image is still published.