monitoring: add initial implementation of prometheus

roles/alpina/collections/services/monitoring/templates/docker-compose.yml.j2

@@ -53,3 +53,13 @@ services:
         - /var/log:/var/log:ro
     tmpfs:
       - /tmp
+
+  prometheus:
+    image: prom/prometheus:latest
+    container_name: prometheus
+    restart: unless-stopped
+    user: "{{ remote_uid }}"
+    volumes:
+      - ./prometheus_config:/etc/prometheus:ro
+      - {{ base_volume_path }}/monitoring/prometheus_configs:/etc/prometheus/extra:ro
+      - {{ base_volume_path }}/monitoring/prometheus:/prometheus

roles/alpina/collections/services/monitoring/templates/grafana_config/provisioning/datasources/alpina.yaml.j2

@@ -8,3 +8,11 @@ datasources:
     uid: loki
     url: http://loki:3100
     editable: false
+
+  - name: Prometheus
+    type: prometheus
+    version: 1
+    access: proxy
+    uid: prometheus
+    url: http://prometheus:9090
+    editable: false

roles/alpina/collections/services/monitoring/templates/prometheus_config/prometheus.yml.j2

@@ -0,0 +1,31 @@
+global:
+  scrape_interval: 15s
+  evaluation_interval: 15s
+
+  external_labels:
+    monitor: "{{ ansible_host }}"
+
+scrape_configs:
+  - job_name: "prometheus"
+    static_configs:
+      - targets: ["localhost:9090"]
+
+  - job_name: "node"
+    static_configs:
+      - targets: ["{{ ansible_host }}:9100"]
+
+  - job_name: "loki"
+    static_configs:
+      - targets: ["loki:3100"]
+
+  - job_name: "promtail"
+    static_configs:
+      - targets: ["promtail:9080"]
+
+rule_files:
+  - "/etc/prometheus/extra/rules/*.yml"
+  - "/etc/prometheus/extra/rules/*.json"
+
+scrape_config_files:
+  - "/etc/prometheus/extra/scrape_configs/*.yml"
+  - "/etc/prometheus/extra/scrape_configs/*.json"

roles/common/tasks/main.yml

@@ -5,6 +5,7 @@
      - docker-ce
      - docker-compose-plugin
      - firewalld
+     - prometheus-node-exporter
     state: latest
 
 - name: Upgrade Debian packages