How to do it...

1. Create the project from the following template:

$ sls create --template-url https://github.com/danteinc/js-cloud-native-cookbook/tree/master/ch1/create-api-gateway --path cncb-create-api-gateway

2. Navigate to the cncb-create-api-gateway directory with cd cncb-create-api-gateway.
3. Review the file named serverless.yml with the following content:

service: cncb-create-api-gateway

provider:
  name: aws
  runtime: nodejs8.10

functions:
  hello:
    handler: handler.hello
    events:
      - http:
          path: hello
          method: get
          cors: true

4. Review the file named handler.js with the following content:

module.exports.hello = (event, context, callback) => {
  console.log('event: %j', event);

  const response = {
    statusCode: 200,
    headers: {
      'Access-Control-Allow-Origin': '*',
    },
    body: JSON.stringify({
      message: 'JavaScript Cloud Native Development Cookbook! Your function executed successfully!',
      input: event,
    }),
  };

  callback(null, response);
};

5. Install the dependencies with npm install.
6. Run the tests with npm test.
   
7. Review the contents generated in the .serverless directory.
8. Deploy the stack: 

$ npm run dp:lcl -- -s $MY_STAGE

> cncb-create-api-gateway@1.0.0 dp:lcl <path-to-your-workspace>/cncb-create-api-gateway
> sls deploy -r us-east-1 "-s" "john"

Serverless: Packaging service...
.....
Serverless: Stack update finished...
Service Information
service: cncb-create-api-gateway
stage: john
region: us-east-1
stack: cncb-create-api-gateway-john
api keys:
  None
endpoints:
  GET - https://k1ro5oasm6.execute-api.us-east-1.amazonaws.com/john/hello
functions:
  hello: cncb-create-api-gateway-john-hello

9. Review the stack, API, and function in the AWS Console.
10. Invoke the endpoint shown in the stack output in the following commands:

$ curl -v https://k1ro5oasm6.execute-api.us-east-1.amazonaws.com/john/hello | json_pp

{
   "input" : {
      "body" : null,
      "pathParameters" : null,
      "requestContext" : { ... },
      "resource" : "/hello",
      "headers" : { ... },
      "queryStringParameters" : null,
      "httpMethod" : "GET",
      "stageVariables" : null,
      "isBase64Encoded" : false,
      "path" : "/hello"
   },
   "message" : "JavaScript Cloud Native Development Cookbook! Your function executed successfully!"
}

11. Take a look at the logs:

$ sls logs -f hello -r us-east-1 -s $MY_STAGE

START ...
2018-03-25 01:04:47 ... event: {"resource":"/hello","path":"/hello","httpMethod":"GET","headers":{ ... },"requestContext":{ ... },"body":null,"isBase64Encoded":false}
END 
REPORT ... Duration: 2.82 ms    Billed Duration: 100 ms ... Max Memory Used: 20 MB    

12. Remove the stack once you are finished with npm run rm:lcl -- -s $MY_STAGE.