Consider removing H2 dependency

[onobc]

So....

The H2 config was split into its own config and made optional in #4802 as it was lighting up CVE scans.

We quickly realized the missing dep. broke running locally w/ java -jar as well as many examples that do the same in the docs. Because of this I made the dependency non-optional here.

As of now the dependency is still provided. We need to decide what we are going to do in this area (provide it or not).

Originally posted by @onobc in #5082 (comment)

[onobc]

From @jvalkeal ...

Lets follow up to see what Boot is doing in the version where H2 still has the CVE. IOW - if Boot has decided to leave it in we can follow suit based on the same principles.

Also is the latest H2 lib w/o the CVE able to run in SCDF?

[michael-wirth]

Hi @onobc

From a developer's point of view, it is bad to have unnecessary dependencies on the classpath, just because of a "local/developer" setup and examples. In a prod environment normally a persistent database is used. In some companies, an h2database dependency will always raise a red flag even without CVE reports.

[onobc]

Hi @michael-wirth,
I agree w/ you and I would like to remove the dependency as well.

It is not that we want to use H2 specifically, or that we want it on the classpath.
Rather, we want it to be easy to start a local env for quickstart, local dev, manual testing, etc..
As you pointed out, the latter can be solved multiple ways. We just did not get a chance to get back to this in 2.10.0. We will aim for 2.10.1.

Thanks for the feedback.

[onobc]

GOAL: It should be easy to start a local env for quickstart, local dev, manual testing, etc..

Once H2 is removed from the class path here are some possible options to realize the above goal.

Option 1: Provide a script that adds the H2 dep to the local server

Option 2: Provide a script to start MariaDB locally in docker (it should output the command to start SCDF using the newly started MariaDB server)

Option 3:. Provide an artifact(s) that include the H2 dep

I am sure there are other options, just getting these thoughts queued up for when we get back to this.