Add missing iam permission

Author: keithduncan

templates/aws-stack.yml

@@ -1156,6 +1156,9 @@ Resources:
           PolicyDocument:
             Version: '2012-10-17'
             Statement:
+              - Effect: Allow
+                Action: ssm:DescribeInstanceInformation
+                Resource: "*"
               - Effect: Allow
                 Action: ssm:SendCommand
                 Resource: !Sub arn:${AWS::Partition}:ssm:${AWS::Region}:${AWS::AccountId}:document/AWS-RunShellScript