adding sigv4

Author: stephenbawks

Diff for: aws_lambda_powertools/utilities/iam/__init__.py

@@ -0,0 +1,6 @@
+"""Advanced feature flags utility"""
+from .auth import SigV4AuthFactory
+
+__all__ = [
+    "SigV4AuthFactory",
+]

Diff for: aws_lambda_powertools/utilities/iam/auth.py

@@ -0,0 +1,51 @@
+
+from typing import Optional
+from botocore.auth import SigV4Auth
+from botocore.credentials import Credentials
+from boto3 import Session
+
+
+class SigV4AuthFactory:
+    """
+    SigV4 authentication utility
+
+    Args:
+        region (str): AWS region
+        service (str): AWS service
+        access_key (str, optional): AWS access key
+        secret_key (str, optional): AWS secret key
+        token (str, optional): AWS session token
+
+    Returns:
+        SigV4Auth: SigV4Auth instance
+
+    Examples
+    --------
+    **Using default credentials**
+    >>> from aws_lambda_powertools.utilities.iam import SigV4AuthFactory
+    >>> auth = SigV4AuthFactory(region="us-east-2", service="vpc-lattice-svcs")
+
+
+
+    """
+    def __init__(
+        self,
+        region: str,
+        service: str,
+        access_key: Optional[str],
+        secret_key: Optional[str],
+        token: Optional[str],
+    ):
+        self._region = region
+        self._service = service
+
+        if access_key and secret_key or token:
+            self._access_key = access_key
+            self._secret_key = secret_key
+            self._credentials = Credentials(access_key=self._access_key, secret_key=self._secret_key, token=token)
+
+        else:
+            self._credentials = Session().get_credentials()
+
+        def __call__(self):
+            return SigV4Auth(credentials=self._credentials, service=self._service, region=self._region)