* Alerting: Create fewer contact points on migration
Previously a new contact point was created for every unique combination
of channels attached to any legacy alert. This was very hard to maintain,
requiring modifications in every generated contact point.
This change deduplicates the generated contact points to a more
reasonable state. There should now only be one contact point per legacy
channel, and we attached multiple contact points to a route by nesting
them. The sole exception to this is if there were multiple default
legacy channels, in which case we create a redundant contact point
containing all of them used only in the root policy. This allows for a
much simpler notification policy structure.
Co-authored-by: gotjosh <josue.abreu@gmail.com>
* Alerting: Add integration test for AddDashAlertMigration
* Add more targeted test cases
* Apply suggestions from code review
Co-authored-by: gotjosh <josue.abreu@gmail.com>
* Reorganize file and improve comments
* Replace custom sort+trim with go-cmp
* Add test for AddDashAlertMigration
* Rename test cases to standard format
* Apply suggestions from code review
Co-authored-by: gotjosh <josue.abreu@gmail.com>
* Remove test-only snapshots of PostableUserConfig et al.
* Organize imports
* Fix linting
Co-authored-by: gotjosh <josue.abreu@gmail.com>
* update AlertingEnabled and UnifiedAlertingSettings.Enabled to be pointers
* add a pseudo migration to fix the AlertingEnabled and UnifiedAlertingSettings.Enabled if the latter is not defined
* update the default configuration file to make default value for both 'enabled' flags be undefined
Misc
* update Migrator to expose DB engine. This is needed for a ualert migration to access the database while the list of migrations is created.
* add more verbose failure when migrations do not match
Co-authored-by: gotjosh <josue@grafana.com>
Co-authored-by: Yuriy Tseretyan <yuriy.tseretyan@grafana.com>
Co-authored-by: gillesdemey <gilles.de.mey@gmail.com>
* Alerting: Validate contact point configuration during the migration
This minimises the chances of generating broken configuration as part of the migration. Originally, we wanted to generate it and not produce a hard stop in Grafana but this strategy has the chance to avoid delivering notifications for our users.
We now think it's better to hard stop the migration and let the user take care of resolving the configuration manually.
