prometheus: install alertmanager

roles/prometheus/meta/argument_specs.yml

@@ -40,11 +40,24 @@ argument_specs:
           replacement:
             type: str
             required: false
+
       prometheus_install_grafana:
         description: If true, installs grafana in the same docker network as prometheus and configures it with prometheus as data source
         type: bool
         required: false
         default: false
+      prometheus_install_alertmanager:
+        description: If true, installs alertmanager in the same docker network as prometheus and configures it
+        type: bool
+        required: false
+        default: true
+
+      alertmanager_storage_retention:
+        description: Period of time for which alertmanager data is stored for. A number followed by unit (s, m, h, d, w, y). Passed directly to alertmanager role
+        type: str
+        required: false
+        default: "{{ prometheus_storage_retention | default('3650d') }}"
+
 
       # All options after this will be passed directly to the container role
       docker_service_suffix: