Nodejs google cloud function REST API demo

1. Go to Google cloud functions console and create a cloud functions with a name and a function name to specify which function to execute. In this demo, the name is simple-rest-api and the function name is restApi.

2. Run these command to create directories and node js files that will be uploaded to gcloud.

mkdir simple-rest-api
cd simple-rest-api
mkdir functions
cd functions
touch index.js

3. The cloud functions source code in the index.js

exports.restApi = (req, res) => {

	const requestInfo = {
      'customMsg': "This is a custom message, the other fields here are some of the request data, you can do all sorts of things you can imagine with these request data." ,
	  	'method': req.method,
      'headers': req.headers,
	  	'url': req.url,
	  	'path': req.path,
	  	'body': req.body
	}

  /**
   * Other things you can do here:
   * Do something according to the request method, is it a GET, POST, PUT or DELETE.
   * Do something according to the headers, does is have a token you need to verify before processing the request?
   * Do something according to the url and path, do you recognize these url and path?
   * Do somethign according to the body, does the body contain anything intersted to you?
   */

   // Not doing anything for now other than just sending back some of the request info.
  res.status(200).send(JSON.stringify(requestInfo, null, 2));
};

4. Deploy the functions to google cloud.

gcloud functions deploy simple-rest-api

5. After it’s deployed, try these requests for GET, POST, PUT and DELETE, replace the trigger url(https://replace-this-with-your-cloud-project-info.cloudfunctions.net/simple-rest-api) with yours which can be found in your cloud functions console.

curl -H "API_TOKEN: 12345" -H "Content-Type: application/json" -X GET https://replace-this-with-your-cloud-project-info.cloudfunctions.net/simple-rest-api/hello/world/?userid=123

curl -H "Content-Type: application/json" -X POST -d '{"id":"123","name":"james"}' https://replace-this-with-your-cloud-project-info.cloudfunctions.net/simple-rest-api/hello/world/

curl -X PUT https://replace-this-with-your-cloud-project-info.cloudfunctions.net/simple-rest-api/user

curl -X DELETE https://replace-this-with-your-cloud-project-info.cloudfunctions.net/simple-rest-api/user

Complete example in Github