docker-compose fails in some cases

[petergloor]

Depending on the Docker version and installation method docker-compose has been replaced by docker compose in a way docker-compose fails on Linux.

As an example, if the Docker Engine has been installed following the official method to Install Docker Engine on Ubuntu using the apt repository with Ubuntu Noble 24.04 (LTS) the script opensim-docker/image-opensim/run-opensim.sh failed with the message ./run-opensim.sh: line 40: docker-compose: command not found.

This comes because using this installation method installed the docker-compose-plugin, so it appears as a new integrated Docker command "docker compose" that replaces the "docker-compose" CLI application.

This doesn't happen if Docker has been installed using Ubuntu's snap package manager that still seems to use a variant of the docker-compose cli.

In my opinion, the simplest way to resolve this issue, is to provide a notice in the documentation to instruct users to add an alias for docker-compose. I did this by entering the following command in a terminal window:
echo "alias docker-compose='docker compose'" >> ~/.bash_aliases

This added an alias to ~/.bash_aliases (it will be created if it doesn't already exist). After a reboot docker-compose can be used and the script should no longer fail.