switch to env-var AWS credentials

per https://docs.aws.amazon.com/cli/v1/userguide/cli-configure-envvars.html

src/pds/registrysweepers/utils/db/client.py

@@ -33,7 +33,7 @@ def get_opensearch_client(
         raise ValueError(f"must provide both username and password, or neither")
 
     credentials_supplied = username is not None
-    auth = (username, password) if credentials_supplied else get_aws_auth()
+    auth = (username, password) if credentials_supplied else None
 
     try:
         scheme, host, port_str = endpoint_url.replace("://", ":", 1).split(":")
@@ -60,11 +60,7 @@ def get_opensearch_client(
         access_test_failed = True
 
     client = OpenSearch(
-        hosts=[{"host": host, "port": int(port)}],
-        http_auth=auth,
-        use_ssl=use_ssl,
-        verify_certs=verify_certs,
-        connection_class=RequestsHttpConnection,
+        hosts=[{"host": host, "port": int(port)}], http_auth=auth, use_ssl=use_ssl, verify_certs=verify_certs
     )
 
     log.info("Testing OpenSearch client with ping...")
@@ -91,7 +87,7 @@ def get_opensearch_client(
     return client
 
 
-def get_aws_auth() -> AWS4Auth:
+def set_aws_auth():
     # TODO: Implement refresh/rotation based on expiry, if not automatically handled by AWS4Auth
     log.info(f"retrieving aws credentials")
     credential_url_env_key = "AWS_CONTAINER_CREDENTIALS_RELATIVE_URI"
@@ -100,7 +96,11 @@ def get_aws_auth() -> AWS4Auth:
     content = resp.json()
     log.info(json.dumps(content))
 
-    region_name = os.environ.get("AWS_REGION", "us-west-2")
     log.info(f"got aws credentials!")
 
-    return AWS4Auth(content["AccessKeyId"], content["SecretAccessKey"], region_name, "aoss")
+    os.environ["AWS_REGION"] = "us-west-2"
+    os.environ["AWS_ROLE_ARN"] = content["RoleArn"]
+    os.environ["AWS_ACCESS_KEY_ID"] = content["AccessKeyId"]
+    os.environ["AWS_SECRET_ACCESS_KEY"] = content["SecretAccessKey"]
+
+    log.info("wrote aws credentials to environment!")