CloudFront logs to CloudWatch

This is a Terraform module / AWS Lambda function that reads CloudFront standard access logs as they are stored in to S3 by CloudFront, and inserts them in to CloudWatch Logs.

How to use:

1. Add a module definition to your Terraform. See the example below.
2. Update the BUCKET placeholders to match the name of the S3 bucket storing CloudFront logs.

module "cloudfront_log_to_cloudwatch" {
  source = "git::https://github.com/brightbock/cloudfront-logs-to-cloudwatch.git?ref=v0.1.1"

  aws_region         = "us-east-1"
  project_name       = "cloudfront_logs_demo"
  log_group_name     = "cloudfront_logs_demo"
  s3_object_arn_list = ["arn:aws:s3:::BUCKET/*.gz"]
  s3_bucket_name     = "BUCKET"
  lambda_memory_size = "128"
  # exclude_sc_status = "200,204,301,304"
}

Notes:

• This Terraform module includes configuring a aws_s3_bucket_notification resource to configure a S3 bucket notification to trigger the lambda function. Your Terraform must only have one aws_s3_bucket_notification resource for each bucket. If you have existing S3 bucket notifications in Terraform, then set s3_bucket_name = "" here, and use the lambda_function_arn output of this module to add a lambda_function stanza to your existing aws_s3_bucket_notification resource.
• exclude_sc_status is a comma separated list of HTTP status code prefixes. Logs with HTTP status matching this list will not be sent to CloudWatch Logs. For example exclude_sc_status = "2,30,404" would exclude logs with 2xx, 30x, and 404 status codes.
• Understand Cloudwatch Logs pricing before deploying this.
• Various other solutions exist:
  • Using Amazon Athena to query Cloudfront logs
  • CloudFront real-time logs in OpenSearch / Kibana