Merge branch '346541-monitor-metrics-deprecation' into 'master'

Deprecation MR for Monitor:Metrics

See merge request gitlab-org/gitlab!77420

data/deprecations/15-0-deprecate-monitor-metrics.yml

+- name: "Monitor performance metrics through Prometheus" # The name of the feature to be deprecated
+  announcement_milestone: "14.7" # The milestone when this feature was first announced as deprecated.
+  announcement_date: "2022-01-22" # The date of the milestone release when this feature was first announced as deprecated. This should almost always be the 22nd of a month (YYYY-MM-22), unless you did an out of band blog post.
+  removal_milestone: "15.0" # The milestone when this feature is planned to be removed
+  removal_date: "2022-05-22" # The date of the milestone release when this feature was first announced as deprecated. This should almost always be the 22nd of a month (YYYY-MM-22), unless you did an out of band blog post.
+  breaking_change: true # If this deprecation is a breaking change, set this value to true
+  body: | # Do not modify this line, instead modify the lines below.
+     By displaying data stored in a Prometheus instance, GitLab allows users to view performance metrics. GitLab also displays visualizations of these metrics in dashboards. The user can connect to a previously-configured external Prometheus instance, or set up Prometheus as a GitLab Managed App.
+     However, since certificate-based integration with Kubernetes clusters is deprecated in GitLab, the metrics functionality in GitLab that relies on Prometheus is also deprecated. This includes the metrics visualizations in dashboards. GitLab is working to develop a single user experience based on [Opstrace](https://about.gitlab.com/press/releases/2021-12-14-gitlab-acquires-opstrace-to-expand-its-devops-platform-with-open-source-observability-solution.html). An [issue exists](https://gitlab.com/groups/gitlab-org/-/epics/6976) for you to follow work on the Opstrace integration.
+# The following items are not published on the docs page, but may be used in the future.
+  stage: Monitor # (optional - may be required in the future) String value of the stage that the feature was created in. e.g., Growth
+  tiers: [Free] # (optional - may be required in the future) An array of tiers that the feature is available in currently.  e.g., [Free, Silver, Gold, Core, Premium, Ultimate]
+  issue_url: https://gitlab.com/gitlab-org/gitlab/-/issues/346541 # (optional) This is a link to the deprecation issue in GitLab
+  documentation_url: https://docs.gitlab.com/ee/operations/metrics/dashboards/ # (optional) This is a link to the current documentation page
+  image_url: # (optional) This is a link to a thumbnail image depicting the feature
+  video_url: # (optional) Use the youtube thumbnail URL with the structure of https://img.youtube.com/vi/UNIQUEID/hqdefault.jpg
+

doc/update/deprecations.md

@@ -312,6 +312,13 @@ The logging features in GitLab allow users to install the ELK stack (Elasticsear
 
 Planned removal milestone: 15.0 (2022-05-22)
 
+### Monitor performance metrics through Prometheus
+
+By displaying data stored in a Prometheus instance, GitLab allows users to view performance metrics. GitLab also displays visualizations of these metrics in dashboards. The user can connect to a previously-configured external Prometheus instance, or set up Prometheus as a GitLab Managed App.
+However, since certificate-based integration with Kubernetes clusters is deprecated in GitLab, the metrics functionality in GitLab that relies on Prometheus is also deprecated. This includes the metrics visualizations in dashboards. GitLab is working to develop a single user experience based on [Opstrace](https://about.gitlab.com/press/releases/2021-12-14-gitlab-acquires-opstrace-to-expand-its-devops-platform-with-open-source-observability-solution.html). An [issue exists](https://gitlab.com/groups/gitlab-org/-/epics/6976) for you to follow work on the Opstrace integration.
+
+Planned removal milestone: 15.0 (2022-05-22)
+
 ### Pseudonymizer
 
 The Pseudonymizer feature is generally unused,