Configuring Docker as Compute Resource for Satellite 6

instructions.md

• Enable the "Extras" Red Hat channel so you can install Docker ...

#subscription-manager repos --enable rhel-7-server-extras-rpms

• ... and install it

# yum install -y docker

• Make sure to enable the docker service...

# systemctl enable docker

• ... and that it can be run as the apache user (this may be dropped as the code matures)

# usermod -aG docker apache

• Deal with SElinux (this may be dropped as the code matures)

# echo "OPTIONS=--selinux-enabled -H tcp://0.0.0.0:2375 -H unix:///var/run/docker.sock" >> /etc/sysconfig/docker

• Finally, start the docker service

# systemctl start docker

• Test that Docker is working (you should see a similar output as shown below):

# docker ps
CONTAINER ID    IMAGE    COMMAND    CREATED    STATUS    PORTS    NAMES

• Obtain a valid Docker image (use busybox for a fairly small and fast download; I chose to use fedora/ssh for this)

# docker pull fedora/ssh

• Create a new "Docker" Compute Resource and use "http://localhost:2375" for its URL
  • The Test Connection button shows a spinner icon but no confirmation message is displayed to tell you whether things look ok or now

• To create a new container, click the Containers and New container menus, and select the Docker compute resource you created before

• Type fedora/ssh (case matters) in the search field and latest in the Tag field
  • NOTE: for some reason, it wasn't until I manually started a container manually with docker run --name myfedora -t fedora/ssh:latest that this part of the process verified that fedora/ssh was a valid entry by showing a green check mark.

• Type a name for your container...

• Click the TTY checkbox...

• ...and your new container is ready to be started

• ...and running

• You can see your container by going to the All containers submenu under the Containers menu.

When I opened the console for my container I see the following message: Could not load host key: /etc/ssh/ssh_host_ecdsa_key

On RHEL6

# yum install -y docker-io
# echo "other_args=\"--selinux-enabled -H tcp://0.0.0.0:2375 -H unix:///var/run/docker.sock\"" >> /etc/sysconfig/docker

Same message on RHEL6 too: Could not load host key: /etc/ssh/ssh_host_ecdsa_key

Useful info: docker run -it --rm ubuntu:14.04 where ubuntu is a valid container name and 14.04 a valid target.