1.0.0 Release IaaS

docs/adr/012-alerting.md

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+# ADR 012 - Alerting
+
+## Date
+
+- Mar/08/2026
+    - First documentation
+    
+## Status
+
+- Accepted
+
+## Context
+
+- The necessity of observability
+- Difficulty of realizing present status of services
+- Stable restoring process already exists
+
+## Considerations
+
+### Mail based
+
+- MTA is hard to manage even when operator uses this as relay host
+- The mail protocol is complex to implement only for internal mail system for single operator
+
+### Chat based
+
+- Using discord, telegram is easy to get announcment automatically
+- The dependency of external services
+
+## Decisions
+
+- Do not operate alerting system
+    - Single node system for small group doesn't need HA
+    - When single node system is down, the alerting system is also down.
+- When the alert system is needed, implement the system on free instance of external IaaS like AWS or Azure
+
+## Consequences
+
+- Simple management and stable restoring
+    - Check service availability
+    - Check from grafana
+    - Access to node via vpn with ssh
+    - Access to node via physical VLAN
+    - Reprovisioning the node
+- The additional possibility of extension with Cloud services.