Create role for Lambda in account 1

  1. Sign in to the AWS Management Console as an IAM user or role in your AWS account, and open the IAM console at https://console.aws.amazon.com/iam/ .

  2. Click Roles on the left, then create role.

  3. AWS service will be pre-selected, select Lambda, then click Next: Permissions.

  4. Do not select any managed policies, click Next: Tags.

  5. Click Next: Review.

  6. Enter Lambda-Assume-Roles for the Role name then click Create role.

  7. From the list of roles click the name of Lambda-Assume-Roles.

  8. Copy the Role ARN and store for use later in this lab.

  9. Click Add inline policy, then click JSON tab.

  10. Replace the sample json with the following, replacing account1 and account2 with your respective account id’s, us-east-1 region with the region you are using, then click Review Policy.

    {
        "Version": "2012-10-17",
        "Statement": [
            {
                "Sid": "stsassumerole",
                "Effect": "Allow",
                "Action": "sts:AssumeRole",
                "Resource": "arn:aws:iam::account2:role/LambdaS3ListBuckets",
                "Condition": {
                    "StringLike": {
                        "aws:UserAgent": "*AWS_Lambda_python*"
                    }
                }
            },
            {
                "Sid": "logsstreamevent",
                "Effect": "Allow",
                "Action": [
                    "logs:CreateLogStream",
                    "logs:PutLogEvents"
                ],
                "Resource": "arn:aws:logs:us-east-1:account1:log-group:/aws/lambda/Lambda-Assume-Roles*/*"
            },
            {
                "Sid": "logsgroup",
                "Effect": "Allow",
                "Action": "logs:CreateLogGroup",
                "Resource": "*"
            }
        ]
    }
    
  11. Name this policy Lambda-Assume-Roles-Policy, then click Create policy.