Apply bool filter to all enable_prometheus_* variables

Change-Id: I639145a709f1d3b9882bbdfb20a754646d1f5270

ansible/roles/prometheus/defaults/main.yml

@@ -5,13 +5,13 @@ prometheus_services:
   prometheus-server:
     container_name: prometheus_server
     group: prometheus
-    enabled: "{{ enable_prometheus_server }}"
+    enabled: "{{ enable_prometheus_server | bool }}"
     image: "{{ prometheus_server_image_full }}"
     volumes: "{{ prometheus_server_default_volumes + prometheus_server_extra_volumes }}"
     dimensions: "{{ prometheus_server_dimensions }}"
     haproxy:
       prometheus_server:
-        enabled: "{{ enable_prometheus_server }}"
+        enabled: "{{ enable_prometheus_server | bool }}"
         mode: "http"
         external: false
         port: "{{ prometheus_port }}"
@@ -60,14 +60,14 @@ prometheus_services:
     dimensions: "{{ prometheus_alertmanager_dimensions }}"
     haproxy:
       prometheus_alertmanager:
-        enabled: "{{ enable_prometheus_alertmanager }}"
+        enabled: "{{ enable_prometheus_alertmanager | bool }}"
         mode: "http"
         external: false
         port: "{{ prometheus_alertmanager_port }}"
         auth_user: "{{ prometheus_alertmanager_user }}"
         auth_pass: "{{ prometheus_alertmanager_password }}"
       prometheus_alertmanager_external:
-        enabled: "{{ enable_prometheus_alertmanager }}"
+        enabled: "{{ enable_prometheus_alertmanager | bool }}"
         mode: "http"
         external: true
         port: "{{ prometheus_alertmanager_port }}"

ansible/roles/prometheus/templates/prometheus-server.json.j2

@@ -13,7 +13,7 @@
             "preserve_properties": true,
             "optional": true
         }
-{% if enable_prometheus_alertmanager %}
+{% if enable_prometheus_alertmanager | bool %}
         ,{
             "source": "{{ container_config_directory }}/*.rules",
             "dest": "/etc/prometheus/",