feat: enhance cloud check in PostgresLoader to work in any GCP enviro…

…nment

Prior to this change, it only worked in functions.

src/palletjack/extract.py

@@ -7,7 +7,6 @@
 import json
 import logging
 import mimetypes
-import os
 import random
 import re
 import time
@@ -500,7 +499,7 @@ def __init__(self, host, database, username, password, port=5432):
         """
 
         self._class_logger = logging.getLogger(__name__).getChild(self.__class__.__name__)
-        if os.environ.get("FUNCTION_TARGET") is not None:  #: this is an env var specific to cloud functions
+        if utils.is_running_in_gcp():
             self._class_logger.info("running in GCF, using unix socket")
             self.engine = sqlalchemy.create_engine(
                 sqlalchemy.engine.url.URL.create(

src/palletjack/utils.py

@@ -989,3 +989,19 @@ def chunker(sequence, chunk_size):
     """
 
     return (sequence[position : position + chunk_size] for position in range(0, len(sequence), chunk_size))
+
+
+def is_running_in_gcp() -> bool:
+    """Check if the code is running in a GCP environment
+
+    Returns:
+        bool: True if running in a GCP environment, False otherwise
+    """
+
+    #: check if the metadata server is available
+    try:
+        requests.get("http://metadata.google.internal", headers={"Metadata-Flavor": "Google"}, timeout=3)
+    except requests.exceptions.ConnectionError:
+        return False
+
+    return True