Add and configure Alertmanager

roles/monitoring/vars/main/defaults.yml

@@ -3,7 +3,24 @@
 prometheus_version: "2.54.1"
 prometheus_targets:
   node:
-    targets:
-      - raspberry-pi-1.kleinendorst.info:9100
+    - targets:
+        - raspberry-pi-1.kleinendorst.info:9100
+prometheus_alertmanager_config:
+  - static_configs:
+      - targets:
+          - raspberry-pi-1.kleinendorst.info:9093
 # Node exporter
 node_exporter_version: "1.8.2"
+# Alertmanager
+alertmanager_version: "0.27.0"
+# Telegram configuration inspired by this source:
+# https://www.stranatesta.eu/tech/how-to-configure-prometheus-alertmanager-to-send-alerts-to-telegram/#configure-alertmanager
+alertmanager_receivers:
+  - name: telegram
+    telegram_configs:
+      - bot_token: "{{ telegram_bot_token }}"
+        api_url: 'https://api.telegram.org'
+        chat_id: "{{ telegram_chat_id }}"
+        parse_mode: ''
+alertmanager_route:
+  receiver: telegram

roles/monitoring/vars/main/vault.yml

@@ -0,0 +1,10 @@
+$ANSIBLE_VAULT;1.1;AES256
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+6265323966383732393138383339393130663164633039390a366361346331323235323763636561
+35373334656435323933663235656334353338643563303335373039326466366662363066363939
+3730653136366166370a366636306438356461656239376465653763663566333036353439663265
+39653731313366373166613237346133616232373566373835393063303035663037663735663130
+33643438663662393135643639646662303431376366656138666536323336633966656464346262
+35613861346661613566303865376539316631613837373263653238363565353662303539616637
+30643730646261336536663865386562313466383066373861383435353366313064653433643531
+65613963396664616565333832613632626665313638353366646665353836653337