Lets say, we have to do some action for every object uploaded / added to S3 Bucket. We can use DynamoDB Streams along with Lambda to achieve the same.

0. Prerequisites

• AWS CLI pre-configured

1. Clone the repository

   git clone https://github.com/miztiik/serverless-s3-event-processor.git

2. Customize the deployment

   Edit the ./helper_scripts/deploy.sh to update your environment variables. The expected output in cloudwatch logs should look like this,

   AWS_PROFILE="default"
   BUCKET_NAME="sam-templates-011" # bucket must exist in the SAME region the deployment is taking place
   SERVICE_NAME="serverless-s3-event-processor"
   TEMPLATE_NAME="${SERVICE_NAME}.yaml"
   STACK_NAME="${SERVICE_NAME}"
   OUTPUT_DIR="./outputs/"
   PACKAGED_OUTPUT_TEMPLATE="${OUTPUT_DIR}${STACK_NAME}-packaged-template.yaml"

3. Deployment

   We will use the deploy.sh in the helper_scripts directory to deploy our AWS SAM template

   chmod +x ./helper_scripts/deploy.sh
   ./helper_scripts/deploy.sh

4. Test Event Processor

   Upload an object to the S3 Bucket or use the event.json in the src directory to test the lambda function. In the lambda logs you will see the following output,

   {
     "status": "True",
     "TotalItems": {
       "Received": 1,
       "Processed": 1
     },
     "Items": [
       {
         "time": "2019-05-08T18:51:00.097Z",
         "object_owner": "AWS:AIDdR7KsQLWs56LRA",
         "bucket_name": "serverless-s3-event-processor-eventbucket-novet8m933s4",
         "key": "c19cf74b-ca14-4458-b2f1-c97b51789f67.xls"
       }
     ]
   }

You can reach out to us to get more details through here.