Why is my Docker Compose plugin outdated after installing Docker via apt on Linux Mint 22?

Below is an explanation and what to check:

What’s Happening

• Docker Engine vs. Plugin:
  Docker Engine 27 release notes state that Docker CE should bundle the new Compose V2 as a CLI plugin. In your installation, the command docker compose (without a hyphen) gives version v2.10.2 while the standalone docker-compose (with a hyphen) gives v2.32.4. This means two different binaries are in play.

• Why the Mismatch?
  The docker-ce (and docker-ce-cli) package you installed via apt appears to provide an earlier version of the Compose CLI plugin (v2.10.2). In contrast, your standalone installation (or the separate package docker-compose-plugin) shows a newer Compose release (v2.32.4). In this scenario, the docker-compose-plugin package may have been installed after docker-ce, but the "docker compose" command is still picking up the older binary provided by Docker CE’s installation layout.

What to Check

1. Installation Source:
   Make sure that your docker-ce packages are coming from Docker’s official repository. If they are coming from Ubuntu’s repositories, the Compose plugin might not be as up to date.

2. CLI Plugin Location:
   Check which binary is being run for docker compose. Typically, Docker CLI plugins are located in:

   • /usr/lib/docker/cli-plugins/
   • Or possibly in a directory referenced by your PATH.

   Verify that the file there is the updated one. You can inspect it (for example, by checking modification dates or file size) if needed.

3. Package Updates:
   Update your docker-ce and docker-compose-plugin packages to the latest versions available from Docker’s repository. The Docker documentation recommends using Docker’s repository (see Installing via the repository) so that you get the latest Compose V2.

4. PATH Conflicts:
   Confirm that your PATH is not picking up an older binary that might have been left over from a previous installation. For example, if you ran a manual install in the past, the older binary might still be present.

Summary

Your understanding isn’t completely off. According to Docker’s release notes, an updated Docker CE should indeed include the new Compose (invoked as docker compose). In your case, the output of docker compose version showing v2.10.2 indicates that the Docker CE installation (or the CLI plugin supplied with it) is older than expected. That’s why the standalone docker-compose command (installed separately) shows a more recent version (v2.32.4).

The likely culprits are either using packages from different repositories or a leftover older binary in your PATH. To resolve this, verify the source of your installations and update them using the recommended repository method.

By following Docker’s recommendations for installing Docker Compose V2 on Linux, you should be able to have a consistent and up-to-date version across both invocations.