Viewing resource-based IAM policies in Lambda

To view a function's resource-based policy

1. Open the Functions page of the Lambda console.

2. Choose a function.

3. Choose Configuration and then choose Permissions.

4. Scroll down to Resource-based policy and then choose View policy document. The resource-based policy shows the permissions that are applied when another account or AWS service attempts to access the function. The following example shows a statement that allows Amazon S3 to invoke a function named my-function for a bucket named amzn-s3-demo-bucket in account 123456789012.

   Example resource-based policy

   {
       "Version": "2012-10-17",
       "Id": "default",
       "Statement": [
           {
               "Sid": "lambda-allow-s3-my-function",
               "Effect": "Allow",
               "Principal": {
                 "Service": "s3.amazonaws.com"
               },
               "Action": "lambda:InvokeFunction",
               "Resource":  "arn:aws:lambda:us-east-2:123456789012:function:my-function",
               "Condition": {
                 "StringEquals": {
                   "AWS:SourceAccount": "123456789012"
                 },
                 "ArnLike": {
                   "AWS:SourceArn": "arn:aws:s3:::amzn-s3-demo-bucket"
                 }
               }
           }
        ]
   }