Adding possible configuration variables for identity and also linked it to the gateway configuration

[itsnuyen]

Description

When should this change go live?

• This is a bug fix, security concern, or something that needs urgent release support.
• This is already available but undocumented and should be released within a week.
• This on a specific schedule and the assignee will coordinate a release with the DevEx team. (apply hold label or convert to draft PR)
• This is part of a scheduled alpha or minor. (apply alpha or minor label)
• There is no urgency with this change and can be released at any time.

PR Checklist

• My changes are for an already released minor and are in /versioned_docs directory.
• My changes are for the next minor and are in /docs directory (aka /next/).

• My changes require an Engineering review, and I've assigned the Engineering DRI or delegate.
• My changes require a technical writer review, and I've assigned @camunda/tech-writers as a reviewer.

[github-actions]

👋 🤖 🤔 Hello, @jonathanlukas! Did you make your changes in all the right places?

These files were changed only in versioned_docs/version-8.6/. You might want to duplicate these changes in docs/.

• versioned_docs/version-8.6/self-managed/identity/deployment/configuration-variables.md
• versioned_docs/version-8.6/self-managed/zeebe-deployment/configuration/gateway.md

You may have done this intentionally, but we wanted to point it out in case you didn't. You can read more about the versioning within our docs in our documentation guidelines.

[jonathanlukas]

Very good first iteration! Please reach out to me to discuss my comments :)

[jonathanlukas]

Very cool next iteration.

I submitted some small adjustments, maybe the formatter needs to run after they are applied...

I also removed the comment "This setting can also be overridden using the environment variable" as it was only present in some properties.

We could maybe ask the @camunda/tech-writers team whether they have a strategy on how to display this very generic information (as environment variables do always override yaml properties). If not, we could add it above the table as a single sentence.

[jonathanlukas]

lgtm

After @Ben-Sheppard has approved, we need to copy the changes back to 8.4 and 8.5

We should also hold the PR open until we know 100% that 8.7 will contain the same identity arch.

Then, we can move it to /next as well

[akeller]

We should also hold the PR open until we know 100% that 8.7 will contain the same identity arch.

Then, we can move it to /next as well

We'll need validation from the Identity team (I see @Ben-Sheppard is already tagged!) because most Identity topics are rolling to 8.8.

[Ben-Sheppard]

Hey @jonathanlukas and @akeller - thats correct, we will have the old Identity architecture available in 8.7 so these configuration changes are still relevant there