Allow customization of probes path and host

[ecerulm]

Closes #12632

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[ecerulm]

@mik-laj since you are reviewing #12619 , I guess it make sense if you review #12630 and #12634 as all of them are about getting ingresses to work properly.

[ecerulm]

I've been thinking about the whole ingress situation. Even after this and #12619 are merged, in order to get a working airflow ingress with a custom hostname and path in AWS EKS the following will be required

• ingress.web.annotations Revert "Hide ToC from the Apache Airflow doc main page (#12589)" #12607
• ingress.web.host: www.example.com
• ingress.web.path: /airflow/*
• config.web.server.base_url: https://www.example.com/airflow
• webserver.livenessProbe.path: /airflow/health
• webserver.livenessProbe.host: www.example.com
• webserver.readinessProbe.path: /airflow/health
• webserver.readinessProbe.host: www.example.com

So there is lot of repetition and matching required, the hostname appears in base_url, ingress.web.host and webserver.*.host.
The path prefix /airflow appear in ingress.web.path and webserver.*.path.

I'm thinking to create yet another PR after the others are merged that takes ingress.web.host and ingress.web.path and fills values for config.web.server.base_url and webserver.*.{path,host}if they are not explicitly provided. Is that something that you would be interested on having?

[ecerulm]

@ashb , since you are reviewing #12630 maybe you should also take a look to this one, since both are related ultimately to the helm chart ingresses

[ashb]

Do we ever need different values here -- they are controlled by the same airflow.cfg so these two values should always be the same, right?

[ecerulm]

Yes, the values will be the same, and they need to be "in sync" also with .webserver.base_url in airflow.cfg. So now I changed so that it extract the host and path from the webserver.base_url if provided.

[ashb]

Looks good -- but could use the pytest "bare" assert style please:

assert .... is None or assert {"name": ...} in ... etc.

[ecerulm]

No problem, changed the self.assert* into assert xxx

[github-actions]

The PR is likely OK to be merged with just subset of tests for default Python and Database versions without running the full matrix of tests, because it does not modify the core of Airflow. If the committers decide that the full tests matrix is needed, they will add the label 'full tests needed'. Then you should rebase to the latest master or amend the last commit of the PR, and push it with --force-with-lease.