Back up every store: the restic module holds node-backup, the stores contribute their dumps

ADR 0214 / to-be 43. restic keeps one repository per machine and takes a nightly snapshot per
module — 14 daily, 8 weekly, 6 monthly — and restores beside the live data, never over it. postgres,
mssql and mongodb contribute a consistent dump; minio, influxdb, the vault, mailu, gitea and
nextcloud the directories that hold their data.

modules/postgres/module.json

@@ -74,6 +74,13 @@
       "mode": "0700",
       "owner": "999:70"
     },
+    {
+      "id": "dumps",
+      "type": "directory",
+      "path": "${dir:store-data}/dumps",
+      "mode": "0700",
+      "owner": "999:70"
+    },
     {
       "id": "server",
       "type": "container",
@@ -121,5 +128,12 @@
         }
       }
     ]
-  }
+  },
+  "contributions": [
+    {
+      "seat": "node-backup",
+      "kind": "backup",
+      "content": "run docker exec -u postgres postgres sh -c 'cd /var/lib/postgresql/data/dumps && for db in $(psql -Atc \"select datname from pg_database where oid >= 16384 order by 1\"); do pg_dump -Fc -f \"$db.dump.partial\" \"$db\" && mv \"$db.dump.partial\" \"$db.dump\" || exit 1; done'\npath ${dir:dumps}\n"
+    }
+  ]
 }