database syncer

Dockers/database-syncer/sync.sh

@@ -0,0 +1,59 @@
+#!/bin/bash
+# Sync PostgreSQL from SOURCE_DB_URL -> DEST_DB_URL.
+# Source is read-only: only pg_dump (SELECT) with default_transaction_read_only=on.
+set -euo pipefail
+
+log() {
+  echo "[$(date -Iseconds)] $*" >&2
+}
+
+SOURCE_DB_URL="${SOURCE_DB_URL:-}"
+DEST_DB_URL="${DEST_DB_URL:-}"
+
+if [ -z "$SOURCE_DB_URL" ]; then
+  log "ERROR: SOURCE_DB_URL must be set"
+  exit 1
+fi
+if [ -z "$DEST_DB_URL" ]; then
+  log "ERROR: DEST_DB_URL must be set"
+  exit 1
+fi
+
+DUMP_FILE="${DUMP_FILE:-/tmp/db-sync.dump}"
+# Extra safety: force read-only transactions on the source connection.
+export PGOPTIONS_SOURCE="${PGOPTIONS_SOURCE:--c default_transaction_read_only=on}"
+
+log "Starting sync (source -> dest)"
+log "Dumping source (read-only)..."
+
+# pg_dump only reads from source. --clean/--if-exists apply DROP statements to DEST on restore.
+PGOPTIONS="$PGOPTIONS_SOURCE" pg_dump \
+  --format=custom \
+  --no-owner \
+  --no-acl \
+  --verbose \
+  --file="$DUMP_FILE" \
+  "$SOURCE_DB_URL"
+
+log "Restoring into destination (with --clean)..."
+pg_restore \
+  --clean \
+  --if-exists \
+  --no-owner \
+  --no-acl \
+  --verbose \
+  --dbname="$DEST_DB_URL" \
+  "$DUMP_FILE" || {
+    # pg_restore returns non-zero on some non-fatal warnings (e.g. missing roles).
+    # Treat exit code 1 as warning; fail hard on higher codes.
+    status=$?
+    if [ "$status" -gt 1 ]; then
+      log "ERROR: pg_restore failed with exit code $status"
+      rm -f "$DUMP_FILE"
+      exit "$status"
+    fi
+    log "WARNING: pg_restore finished with warnings (exit $status)"
+  }
+
+rm -f "$DUMP_FILE"
+log "Sync completed successfully"