Link merge requests for all non review app deploys

What does this MR do?

This changes how we link merge requests to deployments so that:

1. We link merge requests for any deployment that is not in the "created" state.
2. We do not link merge requests to review app deployments.

We want to link deployments regardless of their status so that we can also show failed and running deploys in the merge request widget (and perhaps in other places). We don't want to link review app deployments since this is not useful, and may lead to deployments to different review app environments showing up on a merge request page.

This builds on the refactoring of the deployment model introduced in merge request !20474 (merged), and moves the linking of merge requests to Deployments::FinishedWorker. This worker is scheduled every time a deployment transitions to a finished state.

As part of these changes we also change Deployment#link_merge_requests so that it ignores any already linked merge requests. This way if a deployment changes its status multiple times, we don't error with duplicate key errors.

This fixes #38092 (closed), #38000 (closed).

Does this MR meet the acceptance criteria?

Conformity

• Changelog entry
• Code review guidelines
• Merge request performance guidelines
• Style guides
• Database guides
• Separation of EE specific content

changed milestone to %12.6

added deploy devopsrelease [DEPRECATED] teamDelivery typebug + 1 deleted label

added 134 commits

• 72364704...63534f6e - 132 commits from branch master
• f5cd42e1 - Always use state machine for deployments
• 2db6463a - Link merge requests for all non review app deploys

Compare with previous version

	1 Message
	Consider setting merge_request to 21254 in changelogs/unreleased/fix-linking-merge-requests.yml. See the documentation.

Reviewer roulette

Changes that require review have been detected! A merge request is normally reviewed by both a reviewer and a maintainer in its primary category (e.g. frontend or backend), and by a maintainer in all other categories.

To spread load more evenly across eligible reviewers, Danger has randomly picked a candidate for each review slot. Feel free to override this selection if you think someone else would be better-suited, or the chosen person is unavailable.

Once you've decided who will review this merge request, mention them as you normally would! Danger does not (yet?) automatically notify them for you.

Category	Reviewer	Maintainer
backend	Jarka Košanová (@jarka)	Robert Speicher (@rspeicher)

Generated by Danger

added 311 commits

• 2db6463a...cb01f843 - 309 commits from branch master
• fb3083b3 - Always use state machine for deployments
• ad65f9a1 - Link merge requests for all non review app deploys

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added 92 commits

• ad65f9a1...4618707d - 90 commits from branch master
• 23439b3a - Always use state machine for deployments
• 42dc8473 - Link merge requests for all non review app deploys

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added 2 commits

• b29f929c - Always use state machine for deployments
• d14d7a68 - Link merge requests for all non review app deploys

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added 746 commits

• d14d7a68...849b2c77 - 745 commits from branch master
• 3b217c68 - Link merge requests for all non review app deploys

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@dosuken123 Could you take a look at these changes? Thanks!

assigned to @dosuken123

@yorickpeterse Thanks. I left a few questions. Let me know what you think.

unassigned @dosuken123

changed the description

added 1 commit

• e5027a9b - Link merge requests for all non review app deploys

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resolved all threads

assigned to @dosuken123

approved this merge request

@yorickpeterse Thanks. LGTM

unassigned @dosuken123

assigned to @rspeicher

@rspeicher Could you take a look as a maintainer? Thanks!

changed milestone to %12.7

added missed:12.6 label

mentioned in issue #38092 (closed)

added 913 commits

• e5027a9b...df0d8f2c - 912 commits from branch master
• b5076761 - Link merge requests for all non review app deploys

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changed the description

resolved all threads

@yorickpeterse Looks good, just some minor questions.

unassigned @rspeicher

assigned to @rspeicher

added 161 commits

• b5076761...870c49ae - 160 commits from branch master
• 67c20fc4 - Link merge requests for all non review app deploys

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resolved all threads

approved this merge request

@yorickpeterse LGTM, thanks!

enabled an automatic merge when the pipeline for 67c20fc4 succeeds

merged

mentioned in commit 5278996c

This merge request has been deployed to the GitLab.com environment gstg in GitLab auto-deploy version 12.7.202001050505-0b0892e71da.6254680766a.

A list of all the deployed commits can be found here.

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added workflowstaging label

This merge request has been deployed to the GitLab.com environment gprd-cny in GitLab auto-deploy version 12.7.202001051105-de02d30675f.6ee76535eb4.

A list of all the deployed commits can be found here.

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added workflowcanary label and removed workflowstaging label

mentioned in issue #35741

This merge request has been deployed to the GitLab.com environment gprd in GitLab auto-deploy version 12.7.202001062105-f2d6a8f3378.85c0781518c.

A list of all the deployed commits can be found here.

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If this message is incorrect, please create an issue in the Release Tools project.

added workflowproduction label and removed workflowcanary label

mentioned in epic &1936

mentioned in commit 7816adee