Introduction Lambda & SLS Framwork: Slides

hello

Leo

Dev at TURBINE XBERG

wh0t is lambda

compute service
executed on amazon infrastructure
don't need to manage server
pay per per run time
zero configuration auto scaling
each piece of your code is called lambda function
java, python, nodejs, go
every function is stateless

stateless

zero config
run independant from env
not connected to underlaying infrastructure
scale easily
easy to test

function holds all information that it needs to execute

states -> db

run lambda, run!

event based
events from other AWS services (S3, dynamoDb etc.)
HTTP calls
other lambda functions
serverless execution

serverless

there are servers
but you don't care about servers
function as a service

let's go shopping

Serverless Framework FTW!!!1

you need

nodejs v6.5.0+
Serverless CLI v1.9.0+
```
$ npm install -g serverless
```
FaaS provider account
set up provider credentials

serverless framework

FaaS provider abstraction layer
configure your app in a .yml file:
permissions, resources, functions, routes, events
CLI tool
deploy your app to any FaaS provider
invoke functions
...

key concepts

functions
events
resources
plugins

serverless.yml

service: my-app

provider:
  name: aws
  runtime: nodejs6.10
  stage: dev
  region: eu-central-1

functions:
  homePage:
    handler: src/homePage.handler
    events:
      - http: 'GET /'

src/homePage.js

'use strict';

module.exports.handler = (event, context, callback) => {
  
  const response = {
    statusCode: 200,
    body: JSON.stringify({
      message: 'Welcome to my website',
      input: event,
    }),
  };

  callback(null, response);
};

add dynamoDb permissions

serverless.yml

service: my-app

provider:

  ...

  environment:
    DYNAMODB_LOG_TABLE: ${self:service}-request-log-${self:provider.stage}
  iamRoleStatements:
    - Effect: Allow
      Action:
        - dynamodb:Query
        - dynamodb:Scan
        - dynamodb:PutItem
      Resource: "arn:aws:dynamodb:${self:provider.region}:*:table/${self:provider.environment.DYNAMODB_LOG_TABLE}"

...

define table

serverless.yml

resources:
  Resources:
    RequestLogDynamoDbTable:
      Type: 'AWS::DynamoDB::Table'
      Properties:
        AttributeDefinitions:
          -
            AttributeName: id
            AttributeType: S
        KeySchema:
          -
            AttributeName: id
            KeyType: HASH
        ProvisionedThroughput:
          ReadCapacityUnits: 1
          WriteCapacityUnits: 1
        TableName: ${self:provider.environment.DYNAMODB_LOG_TABLE}

src/homePage.js

const uuid = require('uuid');
const aws = require('aws-sdk');
const dynamoDb = new aws.DynamoDB.DocumentClient();

module.exports.handler = (event, context, callback) => {

  ...

  const params = {
    TableName: process.env.DYNAMODB_LOG_TABLE,
    Item: {
      id: uuid.v1(),
      function: 'homePage.handler',
      requestTime: new Date().getTime()
    },
  };

  dynamoDb.put(params, (error) => {
    if(error) {
      // we should do some error handling ...
      console.log(error);
    }
    callback(null, response);
  }
};

local development

# install plugins

$ npm install serverless-offline --save-dev
$ npm install serverless-dynamodb-local --save-dev

# add plugins to serverless.yml

# start offline server

$ sls dynamodb install 
$ sls dynamodb start --migrate 
$ sls offline start
$ sls invoke local -f homePage

kickstart

create app
$ sls create --template aws-nodejs --path my-app

deploy app   
$ sls deploy

deploy single function
$ sls deploy -f my-function

run function
$ sls invoke -f my-function

see live logs like tail -f
$ sls logs -f my-function -t

remove everything
$ sls remove

thanks for listening

serverless examples:

https://github.com/serverless/examples

serverless official:

https://serverless.com