Plan approach to GHCR image problem / CLI / Docker images

[patchwork01]

Background

We've had problems with the Docker implementation of the Sleeper CLI as the Docker images keep getting deleted from GHCR:

• Sleeper CLI Docker images on main branch can't be pulled #2494

We're also likely to replace the current Sleeper CLI, scripts and admin client with a version that runs directly in Java:

• Unify admin client and related scripts #1328

Description

We'd like to decide what we should do with the Docker images that are currently held in GHCR, and how we should deal with the linked bug in GHCR. We'd like to understand how this relates to our plans for the CLI and admin client.

Analysis

We could handle this as part of the linked epic (#1328). That could replace the Docker-based CLI entirely.

Possible replacements

The sleeper builder Docker image could be replaced entirely with Nix, as in #2683 and #2826.

The sleeper environment Docker image could be combined into the Java-based CLI, which could handle retrieving and running the cdk-environment CDK app.

The sleeper deployment Docker image should no longer be needed if we combine all the scripts into a single Java-based CLI. It can retrieve the separate jars as they are needed. It's also not often used, and will be removed in #2751.

We could store the jars somewhere instead of the Docker images. GitHub Packages may be suitable for this.

Single image tag

Rather than get rid of the images entirely, we could only have one set of images which are the latest version. We can design it so that there's no need for any older version. At time of writing, we've removed the deployment Docker image, so there's no link between the CLI and any particular released version of Sleeper.

The following issue should resolve this:

• Only build Sleeper CLI Docker images against develop #2857

Combined with the linked epic to improve and unify the clients, this should resolve the problem:

• Unify admin client and related scripts #1328