Add sleep option to FE entrypoint

[MrCreosote]

Useful for debugging configs in Rancher if the service doesn't start

[Tianhao-Gu]

👍

[bio-boris]

The trick is to set the entrypoint to /bin/sleep and the cmd to infinity so you can put any container to sleep without needing to modify anything. Most containers have /bin/sleep built in

[bio-boris]

Then you can call your old entrypoint as usual, since its a bash script, and you can figure out exactly where it crashes and such.

[MrCreosote]

The docker compose set up from starrocks had a sleep in the (long) command, so when I converted the image to use envvars I put the sleep in the entry point so it behaved the same way. I just copied the same thing to the fe here.

Plus it lets you just set an envvar instead of changing the entrypoint and command