This severless function was created to be able to copy files from one S3 bucket into a subfolder in another S3 bucket cross account. After a user placed a file into this Bucket, a S3 Event Notification for the respected file triggered a PUT operation for the new file that triggered this lambda. The Event Notification has a prefix that it is looking for, so that it will only be triggered if a file with the specified prefix is stored to this bucket. Since S3 native Replication Rules do not support copying files from S3 to a different S3 into its SUBFOLDER, I created this lambda.
Two policies are added, both handle lambda access rights. "policy-s3-destination-account.json" will grant the desired permission so that the lambda can run copy the object to destionation bucket, whereas "policy-s3-source-bucket.json" allows the lambda to run in the source account and get the desired file.
After you cloned this repo, run go mod init main.go, then run go mod tidy. Now you can run the script to build the binary with sh build.sh