Cleanup aws unit test hang

Signed-off-by: Pedro Algarvio <palgarvio@vmware.com>

salt/utils/aws.py

@@ -7,7 +7,7 @@ This is a base library used by a number of AWS services.
 
 :depends: requests
 """
-
+import binascii
 import copy
 import hashlib
 import hmac
@@ -15,43 +15,18 @@ import logging
 import random
 import re
 import time
+import urllib.parse
+import xml.etree.ElementTree as ET
 from datetime import datetime
 
+import requests
+
 import salt.config
 import salt.utils.hashutils
 import salt.utils.xmlutil as xml
 
-try:
-    import requests
-
-    HAS_REQUESTS = True  # pylint: disable=W0612
-except ImportError:
-    HAS_REQUESTS = False  # pylint: disable=W0612
-
-try:
-    import binascii
-
-    HAS_BINASCII = True  # pylint: disable=W0612
-except ImportError:
-    HAS_BINASCII = False  # pylint: disable=W0612
-
-try:
-    import urllib.parse
-
-    HAS_URLLIB = True  # pylint: disable=W0612
-except ImportError:
-    HAS_URLLIB = False  # pylint: disable=W0612
-
-try:
-    import xml.etree.ElementTree as ET
-
-    HAS_ETREE = True  # pylint: disable=W0612
-except ImportError:
-    HAS_ETREE = False  # pylint: disable=W0612
-
-# pylint: enable=import-error,redefined-builtin,no-name-in-module
-
 log = logging.getLogger(__name__)
+
 DEFAULT_LOCATION = "us-east-1"
 DEFAULT_AWS_API_VERSION = "2016-11-15"
 AWS_RETRY_CODES = [

tests/pytests/unit/utils/test_aws.py

@@ -4,17 +4,30 @@
 
     Test the salt aws functions
 """
-
 import io
+import os
 import time
 from datetime import datetime, timedelta
 
+import pytest
 import requests
 
 import salt.utils.aws as aws
+from tests.support.helpers import patched_environ
 from tests.support.mock import MagicMock, patch
 
 
+@pytest.fixture(autouse=True)
+def _cleanup():
+    # Make sure this cache is clear before each test
+    aws.__AssumeCache__.clear()
+    # Remove any AWS_ prefixed environment variables
+    with patched_environ(
+        __cleanup__=[k for k in os.environ if k.startswith("AWS_")],
+    ):
+        yield
+
+
 def test_get_metadata_imdsv1():
     response = requests.Response()
     response.status_code = 200