Enable custom postgres config in devservice

[newur]

I missed a way to configure Postgres in dev services. So far it is only possible for MariaDB/MySQL. So I added a similar approach.

Additionally, the dev services docu is scattered in quiet a lot of places. I created a new common page. similar to the other (much simpler) dev services. This is more or less independent from the code change - except for the added config example for postgres.

[gsmet]

Thanks!

I added a couple of suggestions.
I'm not sure about the split of the guide but yeah maybe it makes sense.

But could you make the changes in two seperate commits of this PR as they are really unrelated (if you don't feel comfortable doing that with git, I can do it and keep your authorship).

[gsmet]

I had a closer look at this one and setCommand() is coming from GenericContainer so it is supported by all the databases.
Thus I think it should be made a global config and not part of this container properties thing.

Let's wait until #25530 is in. Then it should be easier to add an Optional<String> command to the config and consume it in all the *DevServicesProcessor.

[newur]

I had a closer look at this one and setCommand() is coming from GenericContainer so it is supported by all the databases. Thus I think it should be made a global config and not part of this container properties thing.

Let's wait until #25530 is in. Then it should be easier to add an Optional<String> command to the config and consume it in all the *DevServicesProcessor.

I am not sure if I got you correctly here. You are right that setCommand() is coming from the GenericContainer. However, this overrides the Docker specific start command. I am not sure if in general all databases accept configuration parameters in this way.

If all database support it (or in general the user should have more controll over the dev startup) a global config sounds very good. +1

[gsmet]

Well, you're not adding parameters to the database, you're changing the command used to start the container, be it for PostgreSQL or the others.

[newur]

Right, this is what I said. Just wanted to raise my concern about the statement

it is supported by all the databases

[gsmet]

Ah OK, I misunderstood what you said. My point is that even if you cannot push config parameters, well, it's optional so you're not forced to use it. And you might have other reasons to override the command.

I think it's better than introducing something specific to PostgreSQL given it's a general thing.

[gsmet]

@newur I merged #25530 . Would you revisit this with a Optional<String> command in the config consumed by all the databases?

[gsmet]

Perfect, thanks. Sorry for the delay in reviewing!