add group label (login,control,compute) to prom targets

Author: sjpb

ansible/filter_plugins/utils.py

@@ -11,17 +11,26 @@
 import os.path
 import re
 
-def prometheus_node_exporter_targets(hosts, hostvars, env_key):
+def prometheus_node_exporter_targets(hosts, hostvars, env_key, group):
+    """ Return a mapping in cloudalchemy.nodeexporter prometheus_targets
+        format.
+
+        hosts: list of inventory_hostnames
+        hostvars: Ansible hostvars variable
+        env_key: key to lookup in each host's hostvars to add as label 'env' (default: 'ungrouped')
+        group: string to add as label 'group'
+    """
     result = []
     per_env = defaultdict(list)
     for host in hosts:
         host_env = hostvars[host].get(env_key, 'ungrouped')
         per_env[host_env].append(host)
     for env, hosts in per_env.items():
         target = {
-            "targets": ["{target}:9100".format(target=target) for target in hosts],
+            "targets": [f"{target}:9100" for target in hosts],
             "labels": {
-                "env": env
+                'env': env,
+                'group': group
             }
         }
         result.append(target)

environments/common/inventory/group_vars/all/prometheus.yml

@@ -24,7 +24,9 @@ prometheus_alert_rules: []
 
 # Can set a hostvar 'prometheus_env' to an arbitrary string to group prometheus targets, e.g. by rack.
 prometheus_targets:
-  node: "{{ groups.get('node_exporter', []) | prometheus_node_exporter_targets(hostvars, 'prometheus_env') }}"
+  control: "{{ groups.get('node_exporter', []) | intersect(groups['control']) | prometheus_node_exporter_targets(hostvars, 'prometheus_env', 'control') }}"
+  login: "{{ groups.get('node_exporter', []) | intersect(groups['login']) | prometheus_node_exporter_targets(hostvars, 'prometheus_env', 'login') }}"
+  compute: "{{ groups.get('node_exporter', []) | intersect(groups['compute']) | prometheus_node_exporter_targets(hostvars, 'prometheus_env', 'compute') }}"
 
 prometheus_scrape_configs_default:
 - job_name: "prometheus"
@@ -39,7 +41,9 @@ prometheus_scrape_configs_default:
 - job_name: "node"
   file_sd_configs:
   - files:
-    - /etc/prometheus/file_sd/node.yml
+    - /etc/prometheus/file_sd/control.yml
+    - /etc/prometheus/file_sd/login.yml
+    - /etc/prometheus/file_sd/compute.yml
   relabel_configs:
   # strip off port
   - source_labels: ['__address__']