feat: add GCE_METADATA_DETECT_RETRIES to environment_vars.py

Author: judahrand

google/auth/compute_engine/_metadata.py

@@ -54,7 +54,7 @@
 # Timeout in seconds to wait for the GCE metadata server when detecting the
 # GCE environment.
 try:
-    _METADATA_DEFAULT_TIMEOUT = int(os.getenv("GCE_METADATA_TIMEOUT", 3))
+    _METADATA_DEFAULT_TIMEOUT = int(os.getenv(environment_vars.GCE_METADATA_TIMEOUT, 3))
 except ValueError:  # pragma: NO COVER
     _METADATA_DEFAULT_TIMEOUT = 3
 

google/auth/environment_vars.py

@@ -60,6 +60,11 @@
 """Environment variable providing an alternate ip:port to be used for ip-only
 GCE metadata requests."""
 
+GCE_METADATA_TIMEOUT = "GCE_METADATA_TIMEOUT"
+"""Environment variable defining the timeout in seconds to wait for the
+GCE metadata server when detecting the GCE environment.
+"""
+
 GCE_METADATA_DETECT_RETRIES = "GCE_METADATA_DETECT_RETRIES"
 """Environment variable representing the number of retries that should be
 attempted on metadata lookup.