An AWS Lambda Function to Copy S3 Objects

Node.js 4.3 lambda function to copy objects from a source S3 bucket to one or more target S3 buckets as they are added to the source bucket.

Configuration

IAM Role

Create an IAM role with the a policy that give access to this resources:

{
    "Version": "2012-10-17",
    "Statement": [
        {
            "Effect": "Allow",
            "Action": [
                "s3:GetBucketTagging",
                "s3:GetObject",
                "s3:PutObject"
            ],
            "Resource": [
                "*"
            ]
        },
        {
            "Effect": "Allow",
            "Action": [
                "cloudwatch:*"
            ],
            "Resource": [
                "*"
            ]
        },
        {
            "Effect": "Allow",
            "Action": [
                "logs:*"
            ],
            "Resource": [
                "*"
            ]
        }
    ]
}

If you want you can give acess to all S3 resources like this:

...
        {
            "Effect": "Allow",
            "Action": "s3:*",
            "Resource": "*"
        },
...

S3 Buckets

1. Ensure you have a source and a target bucket. They don't need to reside in the same region.
2. Configure your S3 buckets (see below)

Lambda Function

1. Create a new Lambda function.
2. Sending lambda to AWS:

• ZIP the index.js file and node_modules (Not the folder they're in)
• Upload the ZIP package to your lambda function.

3. Add an event source to your Lambda function:

• Event Source Type: S3
• Bucket: your source bucket
• Event Type: Object Created

4. Set your Lambda function to execute using the IAM role you created above.

Configuration

Configuration is performed by setting tags on the source bucket. Access the bucket's properties, click on Tags and add: Key: TargetBucket Value: YOUR_BUCKET_NAME

For more than one bucket at the same time, just separate the target names with a space. For a bucket at a diferent region you can use bucket-name@us-west-2.

After that when you upload a file to your source bucket, the file should be copied to the target bucket(s).