1 files changed, 77 insertions, 12 deletions

diff --git a/app/models/project_services/prometheus_service.rb b/app/models/project_services/prometheus_service.rb
index fa7b3f2bcaf..58731451429 100644
--- a/app/models/project_services/prometheus_service.rb
+++ b/app/models/project_services/prometheus_service.rb
@@ -7,11 +7,14 @@ class PrometheusService < MonitoringService
 
   #  Access to prometheus is directly through the API
   prop_accessor :api_url
+  boolean_accessor :manual_configuration
 
-  with_options presence: true, if: :activated? do
+  with_options presence: true, if: :manual_configuration? do
     validates :api_url, url: true
   end
 
+  before_save :synchronize_service_state!
+
   after_save :clear_reactive_cache!
 
   def initialize_properties
@@ -20,12 +23,20 @@ class PrometheusService < MonitoringService
     end
   end
 
+  def show_active_box?
+    false
+  end
+
+  def editable?
+    manual_configuration? || !prometheus_installed?
+  end
+
   def title
     'Prometheus'
   end
 
   def description
-    s_('PrometheusService|Prometheus monitoring')
+    s_('PrometheusService|Time-series monitoring service')
   end
 
   def self.to_param
@@ -33,8 +44,16 @@ class PrometheusService < MonitoringService
   end
 
   def fields
+    return [] unless editable?
+
     [
       {
+        type: 'checkbox',
+        name: 'manual_configuration',
+        title: s_('PrometheusService|Active'),
+        required: true
+      },
+      {
         type: 'text',
         name: 'api_url',
         title: 'API URL',
@@ -50,16 +69,16 @@ class PrometheusService < MonitoringService
     client.ping
 
     { success: true, result: 'Checked API endpoint' }
-  rescue Gitlab::PrometheusError => err
+  rescue Gitlab::PrometheusClient::Error => err
     { success: false, result: err }
   end
 
   def environment_metrics(environment)
-    with_reactive_cache(Gitlab::Prometheus::Queries::EnvironmentQuery.name, environment.id, &method(:rename_data_to_metrics))
+    with_reactive_cache(Gitlab::Prometheus::Queries::EnvironmentQuery.name, environment.id, &rename_field(:data, :metrics))
   end
 
   def deployment_metrics(deployment)
-    metrics = with_reactive_cache(Gitlab::Prometheus::Queries::DeploymentQuery.name, deployment.id, &method(:rename_data_to_metrics))
+    metrics = with_reactive_cache(Gitlab::Prometheus::Queries::DeploymentQuery.name, deployment.environment.id, deployment.id, &rename_field(:data, :metrics))
     metrics&.merge(deployment_time: deployment.created_at.to_i) || {}
   end
 
@@ -68,7 +87,7 @@ class PrometheusService < MonitoringService
   end
 
   def additional_deployment_metrics(deployment)
-    with_reactive_cache(Gitlab::Prometheus::Queries::AdditionalMetricsDeploymentQuery.name, deployment.id, &:itself)
+    with_reactive_cache(Gitlab::Prometheus::Queries::AdditionalMetricsDeploymentQuery.name, deployment.environment.id, deployment.id, &:itself)
   end
 
   def matched_metrics
@@ -79,24 +98,70 @@ class PrometheusService < MonitoringService
   def calculate_reactive_cache(query_class_name, *args)
     return unless active? && project && !project.pending_delete?
 
+    environment_id = args.first
+    client = client(environment_id)
+
     data = Kernel.const_get(query_class_name).new(client).query(*args)
     {
       success: true,
       data: data,
       last_update: Time.now.utc
     }
-  rescue Gitlab::PrometheusError => err
+  rescue Gitlab::PrometheusClient::Error => err
     { success: false, result: err.message }
   end
 
-  def client
-    @prometheus ||= Gitlab::PrometheusClient.new(api_url: api_url)
+  def client(environment_id = nil)
+    if manual_configuration?
+      Gitlab::PrometheusClient.new(RestClient::Resource.new(api_url))
+    else
+      cluster = cluster_with_prometheus(environment_id)
+      raise Gitlab::PrometheusClient::Error, "couldn't find cluster with Prometheus installed" unless cluster
+
+      rest_client = client_from_cluster(cluster)
+      raise Gitlab::PrometheusClient::Error, "couldn't create proxy Prometheus client" unless rest_client
+
+      Gitlab::PrometheusClient.new(rest_client)
+    end
+  end
+
+  def prometheus_installed?
+    return false if template?
+    return false unless project
+
+    project.clusters.enabled.any? { |cluster| cluster.application_prometheus&.installed? }
   end
 
   private
 
-  def rename_data_to_metrics(metrics)
-    metrics[:metrics] = metrics.delete :data
-    metrics
+  def cluster_with_prometheus(environment_id = nil)
+    clusters = if environment_id
+                 ::Environment.find_by(id: environment_id).try do |env|
+                   # sort results by descending order based on environment_scope being longer
+                   # thus more closely matching environment slug
+                   project.clusters.enabled.for_environment(env).sort_by { |c| c.environment_scope&.length }.reverse!
+                 end
+               else
+                 project.clusters.enabled.for_all_environments
+               end
+
+    clusters&.detect { |cluster| cluster.application_prometheus&.installed? }
+  end
+
+  def client_from_cluster(cluster)
+    cluster.application_prometheus.proxy_client
+  end
+
+  def rename_field(old_field, new_field)
+    -> (metrics) do
+      metrics[new_field] = metrics.delete(old_field)
+      metrics
+    end
+  end
+
+  def synchronize_service_state!
+    self.active = prometheus_installed? || manual_configuration?
+
+    true
   end
 end