Collect metrics for the Cilium cluster application

changelogs/unreleased/cilium-state-metrics.yml

+---
+title: Add installed state metrics for Cilium cluster application
+merge_request: 35808
+author:
+type: added

doc/development/telemetry/usage_ping.md

@@ -449,6 +449,7 @@ appear to be associated to any of the services running, since they all appear to
 | `clusters_applications_runner`                            | `counts`                             | `configure`   |                  |         | Total GitLab Managed clusters with Runner enabled                          |
 | `clusters_applications_knative`                           | `counts`                             | `configure`   |                  |         | Total GitLab Managed clusters with Knative enabled                         |
 | `clusters_applications_elastic_stack`                     | `counts`                             | `configure`   |                  |         | Total GitLab Managed clusters with Elastic Stack enabled                   |
+| `clusters_applications_cilium`                            | `counts`                             | `configure`   |                  |         | Total GitLab Managed clusters with Cilium enabled                          |
 | `clusters_management_project`                             | `counts`                             | `configure`   |                  |         | Total GitLab Managed clusters with defined cluster management project      |
 | `in_review_folder`                                        | `counts`                             |               |                  |         |                                                                            |
 | `grafana_integrated_projects`                             | `counts`                             |               |                  |         |                                                                            |

lib/gitlab/usage_data.rb

@@ -109,6 +109,7 @@ module Gitlab
             clusters_applications_knative: count(::Clusters::Applications::Knative.available),
             clusters_applications_elastic_stack: count(::Clusters::Applications::ElasticStack.available),
             clusters_applications_jupyter: count(::Clusters::Applications::Jupyter.available),
+            clusters_applications_cilium: count(::Clusters::Applications::Cilium.available),
             clusters_management_project: count(::Clusters::Cluster.with_management_project),
             in_review_folder: count(::Environment.in_review_folder),
             grafana_integrated_projects: count(GrafanaIntegration.enabled),

spec/factories/usage_data.rb

@@ -84,6 +84,7 @@ FactoryBot.define do
       create(:clusters_applications_knative, :installed, cluster: gcp_cluster)
       create(:clusters_applications_elastic_stack, :installed, cluster: gcp_cluster)
       create(:clusters_applications_jupyter, :installed, cluster: gcp_cluster)
+      create(:clusters_applications_cilium, :installed, cluster: gcp_cluster)
 
       create(:grafana_integration, project: projects[0], enabled: true)
       create(:grafana_integration, project: projects[1], enabled: true)

spec/lib/gitlab/usage_data_spec.rb

@@ -315,6 +315,7 @@ RSpec.describe Gitlab::UsageData, :aggregate_failures do
       expect(count_data[:clusters_applications_elastic_stack]).to eq(1)
       expect(count_data[:grafana_integrated_projects]).to eq(2)
       expect(count_data[:clusters_applications_jupyter]).to eq(1)
+      expect(count_data[:clusters_applications_cilium]).to eq(1)
       expect(count_data[:clusters_management_project]).to eq(1)
 
       expect(count_data[:deployments]).to eq(4)