Is that really a problem we want to solve now?

To solve the issue, you are creating indirections here.
Also, we are diverging from the production further.

This can also mislead contributors into thinking that's the way to run stuff.

Instead as suggesting in irc, we should try to solve the T1410 issue (kill implicit configuration).
As a first step towards that, we could first make it able to override default configuration from environment variables (as that's what's needed here to avoid hard-coding values).

Then, there'd be no need for the container-entrypoint.py here.

As a first step towards that, we could first make it able to override default configuration from environment variables (as that's what's needed here to avoid hard-coding values).
Then, there'd be no need for the container-entrypoint.py here.

Or looping to my introduction question, we consider this not a problem to solve right now.

That's acceptable to have temporarily here hard-coded values.
As the problem we are trying to solve immediately is a development environment ready.
Not reuse immediately this for something else.