New way of backporting to active branches using gh action

[ev1yehor]

Release notes

What does this PR do?

Adding new github workflow for creating backports to active branches.

Checklist

• My code follows the style guidelines of this project
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• I have made corresponding change to the default configuration files (and/or docker env variables)
• I have added tests that prove my fix is effective or that my feature works

[robbavey]

It looks like this replaces setup for backport-active-all, backport-active-9 and backport-active-8 in mergify, but I have a couple of questions:

• The backport-active code refers to a Json configuration file. Is this something that the Logstash team maintains in the Logstash repo in a specific location, or is this centrally maintained?
• If it is centrally maintained, does backport-active-all also backport to 7.x, as shown in the example, and when does the json config get updated?

[ev1yehor]

@robbavey This list of active branches based on the Unified Release process. Yes, backport-active-all also backport to 7.17 as it still in this json: https://storage.googleapis.com/artifacts-api/snapshots/branches.json .
@v1v can you correct me if Im wrong here and also explain how this json being updated?

[robbavey]

Will backport-active-all will target 7.x once 9.0 is released?

Once 7.x is released, I would expect that most of our backports would be targeted to 8.x and 9.x releases only

[v1v]

Will backport-active-all will target 7.x once 9.0 is released?

No, we will replace that in the internal implementation, and consumers won't need to do much.

In other words, we decided to change how we used mergify and the definition of what branches to target because the existing implementation in the .mergify.yml does not support dynamic branches.

Instead of using the declarative approach, we use the branches.json as the file to search for the current active branches and mergify github commands to actually use mergify under the hood to create the backports. The GitHub command approach behaves asn the declarative approach

[v1v]

The backport-active code refers to a Json configuration file. Is this something that the Logstash team maintains in the Logstash repo in a specific location, or is this centrally maintained?

No. We, observability robots, are responsible for maintaining that file. We have been using for nearly three years so far in other places.

If it is centrally maintained, does backport-active-all also backport to 7.x, as shown in the example, and when does the json config get updated?

As I mentioned above, we will change that behaviour to skip 7.17 from the backport-active-all.

[robbavey]

Thank you @v1v - sounds like once 9.0 is released, this will do what the previous implementation did with the added bonus of us not having to maintain the versions. Sounds good to me!

[github-actions]

@Mergifyio backport 9.0

[mergify]

backport 9.0

✅ Backports have been created

• #17554 [9.0] (backport #17551) New way of backporting to active branches using gh action has been created for branch 9.0 but encountered conflicts