Break dependency between matrix-prometheus and (matrix-prometheus-node-exporter, matrix-synapse)

group_vars/matrix_servers

@@ -1405,6 +1405,10 @@ matrix_prometheus_enabled: false
 # Prometheus' HTTP port to the local host.
 matrix_prometheus_container_http_host_bind_port: "{{ '' if matrix_nginx_proxy_enabled else '127.0.0.1:9090' }}"
 
+matrix_prometheus_scraper_synapse_enabled: "{{ matrix_synapse_enabled and matrix_synapse_metrics_enabled }}"
+matrix_prometheus_scraper_synapse_targets: ['matrix-synapse:{{ matrix_synapse_metrics_port }}']
+matrix_prometheus_scraper_synapse_rules_synapse_tag: "{{ matrix_synapse_docker_image_tag }}"
+
 matrix_prometheus_scraper_node_enabled: "{{ matrix_prometheus_node_exporter_enabled }}"
 
 ######################################################################

roles/matrix-prometheus/defaults/main.yml

@@ -6,8 +6,6 @@ matrix_prometheus_enabled: false
 matrix_prometheus_docker_image: "docker.io/prom/prometheus:v2.24.1"
 matrix_prometheus_docker_image_force_pull: "{{ matrix_prometheus_docker_image.endswith(':latest') }}"
 
-matrix_synapse_prometheus_rules_download_url: "https://raw.githubusercontent.com/matrix-org/synapse/{{ matrix_synapse_docker_image_tag }}/contrib/prometheus/synapse-v2.rules"
-
 matrix_prometheus_base_path: "{{ matrix_base_data_path }}/prometheus"
 matrix_prometheus_config_path: "{{ matrix_prometheus_base_path }}/config"
 matrix_prometheus_data_path: "{{ matrix_prometheus_base_path }}/data"
@@ -26,6 +24,16 @@ matrix_prometheus_systemd_wanted_services_list: []
 # Takes an "<ip>:<port>" or "<port>" value (e.g. "127.0.0.1:9090"), or empty string to not expose.
 matrix_prometheus_container_http_host_bind_port: ''
 
+# Tells whether the "synapse" scraper configuration is enabled.
+matrix_prometheus_scraper_synapse_enabled: false
+
+# Tells whether to download and load a Synapse rules file
+matrix_prometheus_scraper_synapse_rules_enabled: "{{ matrix_prometheus_scraper_synapse_enabled }}"
+matrix_prometheus_scraper_synapse_rules_synapse_tag: "master"
+matrix_prometheus_scraper_synapse_rules_download_url: "https://raw.githubusercontent.com/matrix-org/synapse/{{ matrix_prometheus_scraper_synapse_rules_synapse_tag }}/contrib/prometheus/synapse-v2.rules"
+
+matrix_prometheus_scraper_synapse_targets: []
+
 # Tells whether the "node" scraper configuration is enabled.
 # This configuration aims to scrape the current node (this server).
 matrix_prometheus_scraper_node_enabled: false

roles/matrix-prometheus/tasks/setup_install.yml

@@ -34,6 +34,17 @@
         matrix_prometheus_scraper_node_targets: ["{{ matrix_docker_network_info.network.IPAM.Config[0].Gateway }}:9100"]
   when: "matrix_prometheus_scraper_node_enabled|bool and matrix_prometheus_scraper_node_targets|length == 0"
 
+
+- name: Download synapse-v2.rules
+  get_url:
+    url: "{{ matrix_prometheus_scraper_synapse_rules_download_url }}"
+    dest: "{{ matrix_prometheus_config_path }}/synapse-v2.rules"
+    force: true
+    mode: 0440
+    owner: "{{ matrix_user_username }}"
+    group: "{{ matrix_user_groupname }}"
+  when: "matrix_prometheus_scraper_synapse_rules_enabled|bool"
+
 - name: Ensure prometheus.yml installed
   copy:
     content: "{{ matrix_prometheus_configuration|to_nice_yaml }}"
@@ -42,15 +53,6 @@
     owner: "{{ matrix_user_username }}"
     group: "{{ matrix_user_groupname }}"
 
-- name: Download synapse-v2.rules
-  get_url:
-    url: "{{ matrix_synapse_prometheus_rules_download_url }}"
-    dest: "{{ matrix_prometheus_config_path }}/synapse-v2.rules"
-    force: true
-    mode: 0440
-    owner: "{{ matrix_user_username }}"
-    group: "{{ matrix_user_groupname }}"
-
 - name: Ensure matrix-prometheus.service installed
   template:
     src: "{{ role_path }}/templates/systemd/matrix-prometheus.service.j2"

roles/matrix-prometheus/tasks/validate_config.yml

@@ -3,5 +3,5 @@
 - name: Fail if Synapse metrics or Prometheus Node Exporter not enabled
   fail:
     msg: >
-      You need to enable `matrix_synapse_metrics_enabled` and/or `matrix_prometheus_node_exporter_enabled` for Prometheus grab metrics.
+      You need to enable `matrix_prometheus_scraper_synapse_enabled` and/or `matrix_prometheus_scraper_node_enabled` for Prometheus grab metrics.
-  when: "not matrix_synapse_metrics_enabled and not matrix_prometheus_node_exporter_enabled"
+  when: "not matrix_prometheus_scraper_synapse_enabled and not matrix_prometheus_scraper_node_enabled"

roles/matrix-prometheus/templates/prometheus.yml.j2

@@ -6,7 +6,7 @@ global:
 
 # Load rules once and periodically evaluate them according to the global 'evaluation_interval'.
 rule_files:
-    {% if matrix_synapse_metrics_enabled %}
+    {% if matrix_prometheus_scraper_synapse_rules_enabled %}
     - 'synapse-v2.rules'
     {% endif %}
 
@@ -26,11 +26,11 @@ scrape_configs:
     static_configs:
       - targets: ['localhost:9090']
 
-  {% if matrix_synapse_metrics_enabled %}
+  {% if matrix_prometheus_scraper_synapse_enabled %}
   - job_name: 'synapse'
     metrics_path: '/_synapse/metrics'
     static_configs:
-    - targets: ['matrix-synapse:{{ matrix_synapse_metrics_port }}']
+    - targets: {{ matrix_prometheus_scraper_synapse_targets|to_json }}
   {% endif %}
 
   {% if matrix_prometheus_scraper_node_enabled %}