campaigns: Switch to changeset syncer per code host

[ryanslade]

We'll launch a syncer per code host Instead of per external service.

Syncer scheduling is coupled to rate limiting which is per code host so this change aligns them.

[codecov]

Codecov Report

Merging #11874 into master will not change coverage.
The diff coverage is n/a.

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##           master   #11874   +/-   ##
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  Coverage   50.44%   50.44%           
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  Files        1513     1513           
  Lines       89703    89703           
  Branches     6742     6742           
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  Hits        45255    45255           
  Misses      40477    40477           
  Partials     3971     3971           

Flag	Coverage Δ
#go	54.85% <0.00%> (ø)
#storybook	10.85% <0.00%> (ø)
#typescript	36.76% <0.00%> (ø)
#unit	50.07% <0.00%> (ø)

[mrnugget]

Instead of this switch statement, can you make use of this map here to check whether the code host is supported?

sourcegraph/internal/campaigns/types.go

Lines 23 to 30 in 9a7d294

	// SupportedExternalServices are the external service types currently supported
	// by the campaigns feature. Repos that are associated with external services
	// whose type is not in this list will simply be filtered out from the search
	// results.
	var SupportedExternalServices = map[string]struct{}{
	extsvc.TypeGitHub: {},
	extsvc.TypeBitbucketServer: {},
	}

That uses "Type*" constants, but since you have the external service at hand, maybe we can get to that from the "kind"?

[ryanslade]

I remembered that we had the BaseURL method on repos.ExternalService, but we're not using it anywhere.

So, I moved that to the extsvc package and renamed it to ExtractBaseURL so that we can use it with either repos.ExternalService or api.ExternalService. That allows us to remove the normalisedURLFromService function.

I also added a function so that we can check campaigns supports an external service "Kind" and use that in the syncer.Add method.

[ryanslade]

The DB backcompat test the only one failing but this change doesn't include any migrations so I'm going to merge it.

[ryanslade]

The DB backcompat test the only one failing but this change doesn't include any migrations so I'm going to merge it.

Ah, I don't have permissions. Looks like I'll probably need to do some merging from master first