[Integ-test] Avoid setting up integration tests networking in local zone

Before this commit, integration tests failed if the account has local zones enabled for the region. Because local zones do not support NAT Gateway

Signed-off-by: Hanwen <[email protected]>

Author: hanwen-cluster

tests/integration-tests/conftest_networking.py

@@ -195,26 +195,27 @@ def subnet_name(visibility="Public", az_id=None, flavor=None):
     return f"{az_id_pascal_case}{visibility}{flavor_string}"
 
 
-def get_availability_zones(region, credential):
+def describe_availability_zones(region, credential):
     """
-    Return a list of availability zones for the given region.
+    Return the response of boto3 describe_availability_zones.
 
     Note that this function is called by the vpc_stacks fixture. Because vcp_stacks is session-scoped,
     it cannot utilize setup_sts_credentials, which is required in opt-in regions in order to call
     describe_availability_zones.
     """
-    az_list = []
     with aws_credential_provider(region, credential):
         client = boto3.client("ec2", region_name=region)
-        response_az = client.describe_availability_zones(
+        return client.describe_availability_zones(
             Filters=[
                 {"Name": "region-name", "Values": [str(region)]},
                 {"Name": "zone-type", "Values": ["availability-zone"]},
             ]
-        )
-        for az in response_az.get("AvailabilityZones"):
-            az_list.append(az.get("ZoneName"))
-    return az_list
+        ).get("AvailabilityZones")
+
+
+def get_availability_zones(region, credential):
+    """Return a list of availability zones for the given region."""
+    return [az.get("ZoneName") for az in describe_availability_zones(region, credential)]
 
 
 def get_az_setup_for_region(region: str, credential: list):
@@ -229,14 +230,7 @@ def get_az_setup_for_region(region: str, credential: list):
 
 def get_az_id_to_az_name_map(region, credential):
     """Return a dict mapping AZ IDs (e.g, 'use1-az2') to AZ names (e.g., 'us-east-1c')."""
-    # credentials are managed manually rather than via setup_sts_credentials because this function
-    # is called by a session-scoped fixture, which cannot make use of a class-scoped fixture.
-    with aws_credential_provider(region, credential):
-        ec2_client = boto3.client("ec2", region_name=region)
-        return {
-            entry.get("ZoneId"): entry.get("ZoneName")
-            for entry in ec2_client.describe_availability_zones().get("AvailabilityZones")
-        }
+    return {entry.get("ZoneId"): entry.get("ZoneName") for entry in describe_availability_zones(region, credential)}
 
 
 # If stack creation fails it'll retry once more. This is done to mitigate failures due to resources