AWS Lambda: S3 Bucket event -> CloudFront Invalidation

When an index* file is created/updated on a S3 bucket, this NodeJS based AWS lambda function finds a distribution that uses the bucket as a origin and creates a wildcard parametrized CloudFront Invalidation.

Installation

If you are not using apex or serverless to manage AWS Lambda functions you can install it by:

1. Installing the dependencies

   npm install
   

2. Zip it and upload the whole zip to AWS Lambda.

3. Create the role for the AWS lambda. For CloudFront the next role policy:

     {
         "Version": "2012-10-17",
         "Statement": [
             {
                 "Effect": "Allow",
                 "Action": [
                     "cloudfront:CreateInvalidation",
                     "cloudfront:ListDistributions",
                     "cloudfront:ListDistributionsByWebACLId",
                     "cloudfront:ListInvalidations"
                 ],
                 "Resource": [
                     "*"
                 ]
             }
         ]
     }
   

And for S3 and logging the role policy:

    {
        "Version": "2012-10-17",
        "Statement": [
            {
                "Effect": "Allow",
                "Action": [
                    "logs:CreateLogGroup",
                    "logs:CreateLogStream",
                    "logs:PutLogEvents"
                ],
                "Resource": "arn:aws:logs:*:*:*"
            },
            {
                "Effect": "Allow",
                "Action": [
                    "s3:GetObject",
                    "s3:PutObject"
                ],
                "Resource": [
                    "arn:aws:s3:::*"
                ]
            }
        ]
    }

4. The handler

    s3-bucket-cf-invalidation.handler
   

5. For the event source, select the S3 bucket(s) related.

Based on this gist by supinf