added n8n

butane/oswald_runner.yaml.tftpl

@@ -42,6 +42,59 @@ systemd:
         RestartSec=5s
         [Install]
         WantedBy=multi-user.target
+    # n8n workflow automation, served publicly at n8n.atlashorizon.net.
+    #
+    # Prerequisites, all of which must exist before the VM is rebuilt:
+    #   - an "n8n" Postgres database and role on argo.lan.atlashorizon.net
+    #   - N8N_DB_PASSWORD and N8N_ENCRYPTION_KEY in Infisical (see
+    #     secrets.tmpl); generate the key with `openssl rand -hex 32`
+    #   - n8n.atlashorizon.net terminating TLS and proxying to this host's
+    #     :5678 (not managed here)
+    #
+    # Workflows, credentials and execution history all live in Postgres, so
+    # a taint loses nothing. The encryption key is what makes that true:
+    # without a fixed one n8n generates its own under /home/node/.n8n, and
+    # the credentials in Postgres become undecryptable the moment the VM
+    # disk goes. Never rotate it without re-entering every credential.
+    - name: n8n.service
+      enabled: true
+      contents: |
+        [Unit]
+        Description=n8n workflow automation
+        After=docker.service
+        Requires=docker.service
+        [Service]
+        TimeoutStartSec=0
+        ExecStartPre=/usr/bin/docker pull docker.n8n.io/n8nio/n8n:2.40.5
+        ExecStartPre=-/usr/bin/docker rm --force n8n
+        # /var/lib/n8n holds only what is left in /home/node/.n8n once the
+        # database and key are external: installed community nodes and
+        # n8n's own config file. Losing it to a taint means reinstalling
+        # community nodes, nothing more.
+        #
+        # N8N_PROXY_HOPS=1: requests arrive through the reverse proxy, so
+        # n8n takes the client IP from X-Forwarded-For (rate limiting and
+        # audit logs would otherwise see only the proxy).
+        ExecStart=/usr/bin/docker run --name n8n \
+          -e DB_TYPE=postgresdb \
+          -e DB_POSTGRESDB_HOST=argo.lan.atlashorizon.net \
+          -e DB_POSTGRESDB_PORT=5432 \
+          -e DB_POSTGRESDB_DATABASE=n8n \
+          -e DB_POSTGRESDB_USER=n8n \
+          -e DB_POSTGRESDB_PASSWORD=${n8n_db_password} \
+          -e N8N_ENCRYPTION_KEY=${n8n_encryption_key} \
+          -e N8N_HOST=n8n.atlashorizon.net \
+          -e N8N_PROTOCOL=https \
+          -e WEBHOOK_URL=https://n8n.atlashorizon.net/ \
+          -e N8N_PROXY_HOPS=1 \
+          -v /var/lib/n8n:/home/node/.n8n \
+          -p 5678:5678 \
+          docker.n8n.io/n8nio/n8n:2.40.5
+        ExecStop=/usr/bin/docker stop n8n
+        Restart=always
+        RestartSec=5s
+        [Install]
+        WantedBy=multi-user.target
     - name: dozzle-agent.service
       enabled: true
       contents: |
@@ -66,3 +119,11 @@ storage:
   directories:
     - path: /var/lib/oswald_runner
       mode: 0755
+    # The n8n image runs as the "node" user (uid 1000), which needs to own
+    # its data directory.
+    - path: /var/lib/n8n
+      mode: 0700
+      user:
+        id: 1000
+      group:
+        id: 1000