Container image reference for the container. The image must have a shell available (i.e. `sh`).

If the image defines an entrypoint it must be able to accept and execute a command and arguments. Jenkins must be able to stop the container and to do so it passes a process monitor command to know when to exit the container. If the image entrypoint to not perform the monitor task the ephemeral container may not work correctly.

Configure an empty command list to disable the entrypoint.

Note: Windows containers are not supported.