Get dns autodiscovery from reclass

Change-Id: I8850be1a118662ebf75a3e0fc2540691ab027220

README.rst

@@ -24,12 +24,29 @@ Configure prometheus server
         address: 0.0.0.0
       external_port: 15010
       target:
+        dns:
+          - name: 'pushgateway'
+            domain:
+            - 'tasks.prometheus_pushgateway'
+            type: A
+            port: 9091
+          - name: 'prometheus'
+            domain:
+            - 'tasks.prometheus_server'
+            type: A
+            port: 9090
         kubernetes:
-          api_ip: 127.0.0.1
+          api_ip: ${_param:kubernetes_control_address}
           ssl_dir: /opt/prometheus/config
           cert_name: kubelet-client.crt
           key_name: kubelet-client.key
-        etcd: ${etcd:server:members}
+        etcd:
+          - host: ${_param:cluster_node01_address}
+            port: ${_param:cluster_node01_port}
+          - host: ${_param:cluster_node02_address}
+            port: ${_param:cluster_node02_port}
+          - host: ${_param:cluster_node03_address}
+            port: ${_param:cluster_node03_port}
       recording:
         - name: 'instance:fd_utilization'
           query: >-

prometheus/files/prometheus.yml

@@ -25,7 +25,7 @@ scrape_configs:
     - targets: [{{ telegraf_nodes | join(',') }}]
 {%- endif %}
 
-{% if server.get('target', {}).etcd is defined %}
+{% if server.get('target', {}).get('etcd') %}
   {%- set etcd_nodes = [] %}
   {%- for node in server.target.etcd %}
     {%- set etcd_address = "'%s:%d'" | format(node.host, node.port) %}
@@ -38,7 +38,7 @@ scrape_configs:
   {%- endif %}
 {%- endif %}
 
-{% if server.get('target', {}).kubernetes is defined %}
+{% if server.get('target', {}).get('kubernetes') %}
   - job_name: 'kubernetes-api'
     scheme: https
     tls_config:
@@ -158,18 +158,13 @@ scrape_configs:
       target_label: kubernetes_pod_name
 {%- endif %}
 
-
+{%- for target in server.get('target', {}).get('dns', []) %}
-  - job_name: 'pushgateway'
+  - job_name: {{ target.name }}
     dns_sd_configs:
     - names:
-      - 'tasks.pushgateway'
+  {%- for domain in target.domain %}
-      type: 'A'
+      - {{ domain }}
-      port: 9091
+  {%- endfor %}
-
+      type: {{ target.type }}
-
+      port: {{ target.port }}
-  - job_name: 'prometheus'
+{%- endfor %}
-    dns_sd_configs:
-    - names:
-      - 'tasks.prometheus'
-      type: 'A'
-      port: {{ server.bind.port }}