Create default-security-group-rules.md

[josephineSei]

a guide for default security group rules

follow-up part of: SovereignCloudStack/standards#521

[berendt]

@markus-hentsch Can you please review this one?

[markus-hentsch]

Suggested change

	This is an exapmle how a table with default Security Group Rules may look like:
	This is an example how a table with default Security Group Rules may look like:

[markus-hentsch]

Suggested change

	The default security Group Rules can differ between default Security Groups and all other Security Groups - called `custom Security Group`.
	Default Security Group Rules may be adjusted individually for one of two different types of Security Groups:
	1. The default Security Groups that are automatically created for projects initially.
	2. Custom Security Groups created by users and initialized with a default rule set.
	The default rule set is configured separately for each of those two types.

I found the original sentence a bit hard to grasp due to the meaning of "default" and "custom" being separate between rules and groups making this multi-dimensional but hard to convey in a single sentence. That's the reason I rephrased this to make a more clear distinction.

[markus-hentsch]

Suggested change

	So it is possible as an administrator to define rules only for one of those groups of Security Groups.
	So it is possible as an administrator to define rules only for one of those types of Security Groups.

[mbuechse]

@josephineSei @markus-hentsch This seems to have been in limbo for weeks. What's the status here?

[josephineSei]

This belonged to SovereignCloudStack/standards#521. Taht issue was closed automatically, when the standard was merged. So this PR was not on my focus anymore.
But as we have a standard document and within that document, we advise to use the current openstack defaults. I don't think we need a guide anymore. What do you think @markus-hentsch ?

[markus-hentsch]

This belonged to SovereignCloudStack/standards#521. Taht issue was closed automatically, when the standard was merged. So this PR was not on my focus anymore. But as we have a standard document and within that document, we advise to use the current openstack defaults. I don't think we need a guide anymore. What do you think @markus-hentsch ?

I agree.

We already added a user-facing guide for custom SG rule handling.
This PR here was initially intended to add an operator-facing guide for the SG rule defaults but since the corresponding standard ended up not deviating from upstream in that regard, all of this can easily be deduced from the standard itself in combination with the upstream documentation of openstack default security group rule ....