Add Template to deploy forgejo.

This template allows deploying a forgejo en either Scaleway or Hetzner
(untested) without much knowledge about them.
It DOES require knowledge about Terragrunt and ansible. A wizard of
sorts is provided but it will not guarantee success without some
knowledge about the underlying technology.

ansible/roles/forgejo/templates/prometheus.yml.j2

@@ -0,0 +1,42 @@
+# Prometheus configuration for Forgejo monitoring
+# Generated by Ansible
+
+global:
+  scrape_interval: 15s
+  evaluation_interval: 15s
+
+scrape_configs:
+  # Forgejo metrics endpoint
+  - job_name: 'forgejo'
+    scheme: http
+    static_configs:
+      - targets: ['forgejo:3000']
+    metrics_path: /metrics
+    bearer_token: '{{ vault_forgejo_metrics_token | default("") }}'
+
+  # Prometheus self-monitoring
+  - job_name: 'prometheus'
+    static_configs:
+      - targets: ['localhost:9090']
+
+{% if forgejo_db_type == 'postgres' %}
+  # PostgreSQL metrics (if postgres_exporter is enabled)
+  # Uncomment and configure if you add postgres_exporter
+  # - job_name: 'postgres'
+  #   static_configs:
+  #     - targets: ['postgres_exporter:9187']
+{% endif %}
+
+{% if forgejo_use_redis %}
+  # Redis metrics (if redis_exporter is enabled)
+  # Uncomment and configure if you add redis_exporter
+  # - job_name: 'redis'
+  #   static_configs:
+  #     - targets: ['redis_exporter:9121']
+{% endif %}
+
+  # Node metrics (if node_exporter is enabled)
+  # Uncomment and configure if you add node_exporter
+  # - job_name: 'node'
+  #   static_configs:
+  #     - targets: ['node_exporter:9100']