Merge pull request #8 from g-n-a-d/master

add sharding ignorances

Author: ntk148v

ansible/roles/prometheus/defaults/main.yml

@@ -41,7 +41,10 @@ prometheus_web_config:
   basic_auth_users: {}
 
 # Prometheus customized arguments
+# -------------------------------
 prometheus_enable_target_sharding: false
+# Job names to ignore sharding
+prometheus_sharding_ignorances: []
 
 # Configuration file options
 # --------------------------

ansible/roles/prometheus/library/inject_sharding_config.py

@@ -21,41 +21,44 @@ def save_config_file(data, path):
         with open(path, 'w') as f:
             json.dump(data, f, indent=2, ensure_ascii=False)
 
-def add_sharding(config, modulus, hash_value):
+def add_sharding(config, modulus, hash_value, ignorances):
     for job in config.get('scrape_configs', []):
-        job['relabel_configs'] = [
-            {
-                'source_labels': ['__address__'],
-                'modulus': modulus,
-                'target_label': '__tmp_hash__',
-                'action': 'hashmod'
-            },
-            {
-                'source_labels': ['__tmp_hash__'],
-                'regex': hash_value,
-                'action': 'keep'
-            }
-        ]
+        if job.get('job_name', '') not in ignorances:
+            job['relabel_configs'].extend([
+                {
+                    'source_labels': ['__address__'],
+                    'modulus': modulus,
+                    'target_label': '__tmp_hash__',
+                    'action': 'hashmod'
+                },
+                {
+                    'source_labels': ['__tmp_hash__'],
+                    'regex': hash_value,
+                    'action': 'keep'
+                }
+            ])
     return config
 
 def main():
     module = AnsibleModule(
         argument_spec=dict(
             source=dict(type='str', required=True),
             modulus=dict(type='int', required=True),
-            hash_value=dict(type='int', required=True)
+            hash_value=dict(type='int', required=True),
+            ignorances=list(type='str', required=True)
         )
     )
 
     source = module.params['source']
     modulus = module.params['modulus']
     hash_value = module.params['hash_value']
+    ignorances = module.params['ignorances']
 
     config = load_config_file(source)
     if not isinstance(config, dict):
         module.exit_json(changed=False)
         return
-    sharded_config = add_sharding(config, modulus, hash_value)
+    sharded_config = add_sharding(config, modulus, hash_value, ignorances)
     save_config_file(sharded_config, source)
 
     module.exit_json(changed=True)

ansible/roles/prometheus/tasks/config.yml

@@ -91,6 +91,7 @@
     source: "{{ prometheus_config_dir }}/prometheus.yml"
     modulus: "{{ groups['prometheus'] | length }}"
     hash_value: "{{ groups['prometheus'].index(inventory_hostname) }}"
+    ignorances: "{{ prometheus_sharding_ignorances }}"
   when: prometheus_enable_target_sharding | bool
 
 - name: Find file_sd configurations on prometheus hosts
@@ -109,6 +110,7 @@
     source: "{{ item.path }}"
     modulus: "{{ groups['prometheus'] | length }}"
     hash_value: "{{ groups['prometheus'].index(inventory_hostname) }}"
+    ignorances: "{{ prometheus_sharding_ignorances }}"
   loop: "{{ host_file_sd.files }}"
   when:
     - prometheus_enable_target_sharding | bool