Chapter 4. Cockpit on Red Hat Enterprise Linux Atomic Host

A Cockpit server can run on Red Hat Enterprise Linux Atomic Host, and Atomic Host servers can be monitored and administered using Cockpit. Additionally, Cockpit can control life cycle of container instances and manipulate container images.

Note

Cockpit does not yet support Kubernetes on Red Hat Enterprise Linux or Red Hat Enterprise Linux Atomic Host servers.

This chapter describes Cockpit features specific to Atomic Host.

4.1. Installing Cockpit on Atomic Host

To install Cockpit on Atomic Host:

  1. Pull the cockpit-ws image:

    # atomic install rhel7/cockpit-ws
  2. Run the cockpit-ws image:

    # atomic run rhel7/cockpit-ws

Now you can log into Cockpit. See Opening the Interface for instructions.

4.2. Cockpit Interface Specific to Atomic Host

In addition to information about systems presented in Getting to know the Cockpit interface, extra tabs appear on Atomic Host systems:

Containers: Lists all images available on the system, all running and non-running containers, combined CPU & memory usage graphs, and a storage usage bar. See Working with Containers for more information on using this tab.

Sunset

Software Updates: Shows the available OSTrees on the system. You can also check for a newer tree, or roll back to a previous version.

Sunset

4.2.1. Working with Containers

The Containers tab presents you with a UI to interact with your Atomic Host images and containers. Apart from the system resources graphs, there are lists of all images you have locally on the system as well as all running and non-running containers.

Download an image. Click the "Get new image" button from the images list to the right and enter an image name or a keyword. Choose an image and click "Download".

Sunset

Starting and stopping containers. From the "Containers" list, you can start and stop containers using the buttons on the right side. Use the drop-down menu to see all or filter out the non-running containers.

Sunset

Click on a container to inspect it. Shows the state, the command executed, the container’s and image’s IDs, a timestamp, as well as the container’s own terminal:

Sunset

Click on an image to inspect it. Shows the image’s ID, entrypoint and command, and a list of containers based on that image. You can also delete the image from here or run a container from it.

Sunset

Run a container. To run a container from an image, either click the triangle button from the right side of the list or choose the image first and then click "Run" from the top right corner. You can then enter the required data for the new container in the following dialog:

Sunset

You can select which command the container should run, and you can also link that container to other containers, which will allow them to interact. Exposing ports for specific services to be visible from the host is also possible.

4.3. Changing the Cockpit port on Atomic Host

To change the Cockpit port on Atomic Host:

atomic run rhel7/cockpit-ws --port 9898

4.4. Enabling more Cockpit features on Atomic Host

You can add more Cockpit features by installing additional cockpit-* packages using package layering.