I heard about the serverless framework so many times , but i didn't really know what it was all about, but last week, i decided to give it a try.

Let's discover it together

First thing : you need to setup your credentials.
If you don't know how to do it, check this link

Install serverless

npm install -g serverless

Create our service in Node JS

serverless create --template aws-nodejs --path test-service

Serverless: Generating boilerplate...
Serverless: Generating boilerplate in "/your/folder/path/test-service"
 _______                             __
|   _   .-----.----.--.--.-----.----|  .-----.-----.-----.
|   |___|  -__|   _|  |  |  -__|   _|  |  -__|__ --|__ --|
|____   |_____|__|  \___/|_____|__| |__|_____|_____|_____|
|   |   |             The Serverless Application Framework
|       |                           serverless.com, v2.19.0
 -------'

Serverless: Successfully generated boilerplate for template: "aws-nodejs"

cd test-service

Two files have been created :

handler.js serverless.yml

Open the files

Since we are using AWS as a provider, all functions inside the service are AWS Lambda functions.

All of the Lambda functions in your serverless service can be found in serverless.yml under the functions property

# serverless.yml

functions:
  hello:
    handler: handler.hello

You can add as many functions as you want within this property.

# serverless.yml

functions:
  hello:
    handler: handler.hello
    description: optional description for your Lambda
  functionTwo:
    handler: handler.functionTwo
  functionThree:
    handler: handler.functionThree

The handler property points to the file and module containing the code you want to run in your function.

# handler.js

'use strict';

# hello
module.exports.hello = async (event) => {
  return {
    # the code you want to run
    ),
  };
};

# functionTwo
module.exports.functionTwo = async (event) => {
  return {
    # the code you want to run
    ),
  };
};

Create and deploy

Let's create and deploy two simple functions.

One function who will say "Hello", and the other one will say "Goodbye" !

# handler.js

'use strict';

module.exports.hello = async (event) => {
  return {
    statusCode: 200,
    body: JSON.stringify(
      {
        message: 'Hello function',
      }
    ),
  };
};

module.exports.goodbye = async (event) => {
  return {
    statusCode: 200,
    body: JSON.stringify(
      {
        message: 'Goodbye function',
      }
    ),
  };
};

#serverless.yml

service: test-service

frameworkVersion: '2'

provider:
  name: aws
  runtime: nodejs12.x
  lambdaHashingVersion: 20201221

functions:
  hello:
    handler: handler.hello
    events:
     - httpApi:
         path: /hello
         method: get
  goodbye:
    handler: handler.goodbye
    events:
     - httpApi:
         path: /goodbye
         method: get

Now, to deploy, juste hit this command

serverless deploy

Serverless: Packaging service...
Serverless: Excluding development dependencies...
Serverless: Creating Stack...
Serverless: Checking Stack create progress...
...
...
Serverless: Stack update finished...
Service Information
service: test-service
stage: dev
region: us-east-1
stack: test-service-dev
resources: 17
api keys:
  None
endpoints:
  GET - https://XXXXXXXXXX.execute-api.us-east-1.amazonaws.com/hello
  GET - https://XXXXXXXXXX.execute-api.us-east-1.amazonaws.com/goodbye
functions:
  hello: test-service-dev-hello
  goodbye: test-service-dev-goodbye
layers:
  None

Now let's check these two endpoints on your browser :

Congrats !

You have now two lambdas running for you on AWS.

Delete ressources

Now , let's clean everything

serverless remove

Serverless: Getting all objects in S3 bucket...
Serverless: Removing objects in S3 bucket...
Serverless: Removing Stack...
Serverless: Checking Stack delete progress...
..................
Serverless: Stack delete finished...

Serverless: Stack delete finished...