part_4

Part 4 - local developer workflow

Generating a test event payload

When you invoke your Lambda function code locally, The invocation must contain an event object with a JSON representation of the HTTP request. The file /eventstestEvent.json has a template API Gateway event. The body of the event is currently empty.

Paste the GitHub webhook payload into the event body:

1. Go to the respository you configured the webhook on and choose Settings > Webhooks > Chose the Webhook.

2. In the Recent Deliveries Choose a delivery and then choose Request. This shows the payload of a recent Webhook.

Before this payload is pasted into the body of the testEvent.json file, it must be converted to a string. Use an online toool such as https://tools.knowledgewalls.com/jsontostring to do this. Copy and paste the JSON payload into the tool and choose Convert.

3. Paste the "stringified" JSON payload into the body field of testEvent.json. The final result will look somthing like this:

Lambda function environment variables

The testharness.js requires 2 important environment variables to run your Lambda function code. These should be added to the part_4/env.json file:

The S3 bucket name value can be found in the outpus when your applicaiton is deployed:

{
"slackEndpoint": "Insert_Slack_Endpoint",
"bucket" : "Insert_S3_Bucket_Name"
}

Dev dependencies

Both Lambda functions in this example application use the AWS SDK to write objects to Amazon S3. To test this from your Local IDE, the AWS SDK for Node.js must be installed as a dev dependancy.

Each function's relative package.json has the following configuration:

 "devDependencies": {
    "aws-sdk": "^2.906.0"
  }

This means that the AWS SDK for Node.js will be installed into the relative node_modules directory when npm install is ran.

The dependancy is NOT copied into an AWS Lambda function when the applicaiton is deployed. This is because the AWS SDK is available to Lambda by default.