add assume role (#39)

Co-authored-by: Puneeth Nanjundaswamy <puneeth@m1.fritz.box>

ecs-cluster/scripts/assume_role.py

@@ -0,0 +1,22 @@
+'''
+  Return STS credentials
+'''
+
+import boto3
+import logging as log
+
+
+def get_temporary_credentials(role_to_assume, region, session_name, duration_seconds=3600):
+  '''
+  Return temporary credentials
+  '''
+
+  log.info('Assuming role {} in region {} with session name {} for {} seconds'.format(
+      role_to_assume, region, session_name, duration_seconds))
+
+  sts_client = boto3.client('sts', region_name=region)
+  assumed_role = sts_client.assume_role(RoleArn=role_to_assume,
+                                        RoleSessionName=session_name,
+                                        DurationSeconds=duration_seconds)
+
+  return assumed_role['Credentials']