hide prometheus manual integration form when auto config is active

app/models/project_services/prometheus_service.rb

@@ -27,6 +27,10 @@ class PrometheusService < MonitoringService
     false
   end
 
+  def editable?
+    !prometheus_installed? || manual_configuration?
+  end
+
   def title
     'Prometheus'
   end
@@ -40,19 +44,13 @@ class PrometheusService < MonitoringService
   end
 
   def fields
+    return [] unless editable?
     [
       {
-        type: 'fieldset',
+        type: 'checkbox',
         name: 'manual_configuration',
-        legend: 'Manual Configuration',
-        fields: [
-          {
-            type: 'checkbox',
-            name: 'manual_configuration',
-            title: s_('PrometheusService|Active'),
-            required: true
-          }
-        ]
+        title: s_('PrometheusService|Active'),
+        required: true
       },
       {
         type: 'text',

app/views/projects/services/prometheus/_help.html.haml

-.row.prepend-top-default.append-bottom-default
-  %p
-    - unless @service.manual_configuration?
-      - if @service.prometheus_installed?
-        = link_to 'Manage installed Prometheus', project_clusters_path(@project), class: 'btn btn-cancel'
-      - else
-        = link_to 'Install Prometheus', project_clusters_path(@project), class: 'btn btn-cancel'
+%h4
+  Auto configuration
+
+.prepend-top-default.append-bottom-default
+  - unless @service.manual_configuration?
+    - if @service.prometheus_installed?
+      = link_to 'Manage clusters', project_clusters_path(@project), class: 'btn'
     - else
-      To automatically install prometheus disable manual configuration
+      = link_to 'Install Prometheus on clusters', project_clusters_path(@project), class: 'btn btn-success'
+  - else
+    .well
+      To enable the installation of Prometheus on your clusters, deactivate the manual configuration below
+
+%hr
+
+%h4.append-bottom-default
+  Manual configuration
 
+- unless @service.editable?
+  .well
+    To enable manual configuration, uninstall Prometheus from your clusters