Draft: Expose prometheus-type HTTP alert integrations in GraphQL

What does this MR do and why?

Related issue: Allow Prometheus' metrics dashboard and incomin... (#338838)

Category:Metrics features were removed in %16.0. This includes the removal of Integrations::Prometheus - except for the ability to ingest alerts from prometheus instances. The alerting portion is being relocated to AlertManagement::HttpIntegration. This MR contains one piece of that relocation. See the implementation plan for details.

There is no UI impact for this MR.

Changes:

• Updates graphql HttpIntegrationType to reference the type_identifier field rather than using a static value
• Allows querying by type on Project.alertManagementHttpIntegrations collection field

New database queries

Triggered by querying Project.alertManagementHttpIntegrations with types argument set to either [] or [HTTP, PROMETHEUS].

SELECT "alert_management_http_integrations".* FROM "alert_management_http_integrations" 
WHERE "alert_management_http_integrations"."project_id" = 6 
ORDER BY "alert_management_http_integrations"."id" DESC 
LIMIT 101

Query plan: https://console.postgres.ai/gitlab/gitlab-production-tunnel-pg12/sessions/23092/commands/74356 (using project_id 14986497)

How to set up and validate locally

1. Open graphql explorer
2. Add prometheus/generic http integrations

Mutation to create prometheus integration

mutation prometheusIntegrationCreate {
  prometheusIntegrationCreate(input: {
    projectPath: "flightjs/Flight",
    active: true
  })  {
    integration {
      id
      type
    }
    errors
  }
}

Mutation to create generic HTTP integrations

mutation httpIntegrationCreate {
  httpIntegrationCreate(input: {
    projectPath: "flightjs/Flight",
    active: true,
    name: "Generic HTTP Integration"
  })  {
    integration {
      id
      type
    }
    errors
  }
}

3. Query Project.alertManagementHttpIntegrations with different type arg values

Query to fetch Alert Integrations

query	fetchAlertManagementHttpIntegrations {
  flight2: project(fullPath: "flightjs/Flight") {
    two: alertManagementHttpIntegrations(types: [HTTP, PROMETHEUS]) {
      nodes {
        id
        name
        type
        url
      }
    }
  }
}

4. Open http://gdk.test:3000/flightjs/Flight/-/settings/operations, expand Alerts ( flightjs/Flight > Settings > Monitor > Alerts )
   • This should show 1 Prometheus integration & however many HTTP integrations you created

MR acceptance checklist

This checklist encourages us to confirm any changes have been analyzed to reduce risks in quality, performance, reliability, security, and maintainability.

• I have evaluated the MR acceptance checklist for this MR.