Add Kopia backup stack with Backblaze B2 offsite target.

Protects /config, selective labdata, and nightly DB dumps; documents homelab improvement plan briefs.

stacks/backup/scripts/backup-dump-databases.sh

@@ -0,0 +1,51 @@
+#!/bin/sh
+# Dump all homelab databases to /config/backup/dumps (gzip SQL).
+# Runs inside backup_scheduler; needs docker.sock.
+set -eu
+
+DUMP_ROOT=/dumps
+STAMP=$(date +%Y%m%d-%H%M%S)
+DIR="${DUMP_ROOT}/${STAMP}"
+mkdir -p "${DIR}"
+
+log() { echo "[backup-dump ${STAMP}] $*"; }
+
+dump_postgres() {
+  name="$1"
+  user="$2"
+  db="$3"
+  if ! docker ps --format '{{.Names}}' | grep -qx "${name}"; then
+    log "skip ${name} (not running)"
+    return 0
+  fi
+  log "dump ${name} → ${db}"
+  docker exec "${name}" pg_dump -U "${user}" "${db}" | gzip -c > "${DIR}/${name}.sql.gz"
+}
+
+dump_mariadb() {
+  name="$1"
+  db="$2"
+  if ! docker ps --format '{{.Names}}' | grep -qx "${name}"; then
+    log "skip ${name} (not running)"
+    return 0
+  fi
+  log "dump ${name} → ${db}"
+  docker exec "${name}" sh -c "mariadb-dump -u root -p\"\$MYSQL_ROOT_PASSWORD\" \"${db}\"" \
+    | gzip -c > "${DIR}/${name}.sql.gz"
+}
+
+log "starting database dumps → ${DIR}"
+
+dump_postgres postgres_gitea gitea gitea
+dump_postgres postgres_plane plane plane
+dump_postgres postgres_authentik authentik authentik
+dump_postgres postgres_famapp famapp famapp
+dump_postgres postgres_resume postgres postgres
+
+dump_mariadb mariadb_bookstack bookstack
+dump_mariadb owncloud_mariadb owncloud
+dump_mariadb romm-db romm
+
+find "${DUMP_ROOT}" -mindepth 1 -maxdepth 1 -type d -mtime +14 -exec rm -rf {} + 2>/dev/null || true
+
+log "done"