Support more query variables in custom dashboards per project

changelogs/unreleased/35475-add-prometheus-ci-vars.yml

+---
+title: Support more query variables in custom dashboards per project
+merge_request: 25732
+author:
+type: added

doc/user/project/integrations/prometheus.md

@@ -155,10 +155,17 @@ Multiple metrics can be displayed on the same chart if the fields **Name**, **Ty
 
 #### Query Variables
 
-GitLab supports a limited set of [CI variables](../../../ci/variables/README.md) in the Prometheus query. This is particularly useful for identifying a specific environment, for example with `CI_ENVIRONMENT_SLUG`. The supported variables are:
+GitLab supports a limited set of [CI variables](../../../ci/variables/README.md) in the Prometheus query. This is particularly useful for identifying a specific environment, for example with `ci_environment_slug`. The supported variables are:
 
-- CI_ENVIRONMENT_SLUG
-- KUBE_NAMESPACE
+- `ci_environment_slug`
+- `kube_namespace`
+- `ci_project_name`
+- `ci_project_namespace`
+- `ci_project_path`
+- `ci_environment_name`
+
+NOTE: **Note:**
+Variables for Prometheus queries must be lowercase.
 
 There are 2 methods to specify a variable in a query or dashboard:
 

lib/gitlab/prometheus/query_variables.rb

@@ -7,7 +7,11 @@ module Gitlab
         {
           ci_environment_slug: environment.slug,
           kube_namespace: environment.deployment_namespace || '',
-          environment_filter: %{container_name!="POD",environment="#{environment.slug}"}
+          environment_filter: %{container_name!="POD",environment="#{environment.slug}"},
+          ci_project_name: environment.project.name,
+          ci_project_namespace: environment.project.namespace.name,
+          ci_project_path: environment.project.full_path,
+          ci_environment_name: environment.name
         }
       end
     end

spec/lib/gitlab/prometheus/query_variables_spec.rb

@@ -11,6 +11,10 @@ describe Gitlab::Prometheus::QueryVariables do
     subject { described_class.call(environment) }
 
     it { is_expected.to include(ci_environment_slug: slug) }
+    it { is_expected.to include(ci_project_name: project.name) }
+    it { is_expected.to include(ci_project_namespace: project.namespace.name) }
+    it { is_expected.to include(ci_project_path: project.full_path) }
+    it { is_expected.to include(ci_environment_name: environment.name) }
 
     it do
       is_expected.to include(environment_filter: