Create wait-for-psql.py

wait-for-psql.py

@@ -0,0 +1,32 @@
+#!/usr/bin/env python3
+import argparse
+import psycopg2
+import sys
+import time
+
+
+if __name__ == '__main__':
+    arg_parser = argparse.ArgumentParser()
+    arg_parser.add_argument('--db_host', required=True)
+    arg_parser.add_argument('--db_port', required=True)
+    arg_parser.add_argument('--db_user', required=True)
+    arg_parser.add_argument('--db_password', required=True)
+    arg_parser.add_argument('--timeout', type=int, default=5)
+
+    args = arg_parser.parse_args()
+
+    start_time = time.time()
+    while (time.time() - start_time) < args.timeout:
+        try:
+            conn = psycopg2.connect(user=args.db_user, host=args.db_host, port=args.db_port, password=args.db_password, dbname='postgres')
+            error = ''
+            break
+        except psycopg2.OperationalError as e:
+            error = e
+        else:
+            conn.close()
+        time.sleep(1)
+
+    if error:
+        print("Database connection failure: %s" % error, file=sys.stderr)
+        sys.exit(1)