Is there a way to specify what I want to run on the container startup?

[PassiveLemon]

I can't seem to find a direct answer. It appears that it runs the server jar file by default but one of my modpacks wants to use its own start.sh. If I use this container for it, I get tons of errors from OOM but running the start.sh independently seems to work fine. I mean this in the sense of an environment variable where I can specify it to run "start.sh" in the data directory rather than whatever the container does by default.

[itzg]

The closest to that is TYPE=CURSEFORGE, described here, where it will unzip the modpack and locate one of several start script names including start.sh. Keep in mind that approach is not actively supported since every modpack has its own script behavior and works against the automation this image provides.