Øredev 2017 - Going Serverless. Conference session about Serverless on the AWS platform presented together with Johannes Pelto-Piri.

1. TELIA FINANCE
mobile application
Going Serverless
Johannes Pelto-Piri
Mattias Severson
Øredev 2017

2. Why
Serverless Application Model (SAM)
Development
Operations
Agenda

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WHY.

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Fast
Scales Stability
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Automation Pay Per Use
Serverless

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Serverless
Event Sources Event Processing Other Services
Kinesis
S3
IoT
API Gateway
3rd Parties Service
Internet
Lambda
Dynamo DB

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DEV.

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Vanilla Serverless
No automation

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Resources:
HelloWorldLambda:
Type: AWS::Lambda::Function
Properties:
S3Bucket: bucket
S3Key: key
Description: A greeting function
FunctionName: GreetingLambda
Handler: index.handler
Role:
Fn::GetAtt:
- LambdaExecutionRole
- Arn
Runtime: nodejs6.10
CloudFormation
LambdaExecutionRole:
Type: AWS::IAM::Role
Properties:
Path: /
ManagedPolicyArns:
- arn:aws:iam::aws:policy/any
hello-world.yml
PlayersAPI:
Type: AWS::ApiGateway::RestApi
Properties:
Name: Hello World API
Body:
swagger: "2.0"
info:
version: "1.0"
title: “hello-world"
paths:
/{name}:
x-amazon-apigateway-any-method:
responses: {}
x-amazon-apigateway-integration:
uri: !Sub "apigateway/../${HelloWorldLambda}"
passthroughBehavior: "when_no_match"
httpMethod: "POST"
type: "aws_proxy"

9. AWS SAM
Serverless Application Model

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AWSTemplateFormatVersion: '2010-09-09'
Transform: AWS::Serverless-2016-10-31
Description: A hello world application.
Resources:
HelloWorldFunction:
Type: AWS::Serverless::Function
Properties:
Handler: index.handler
Runtime: nodejs6.10
CodeUri: .
Events:
HelloWorldResource:
Type: Api
Properties:
Method: get
Path: /{name}
SAM CloudFormation
hello-world.sam.yml

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exports.handler = (event, context, callback) => {
const name = event.pathParameters.name || 'world';
const response = {
statusCode: 200,
headers: {
'Cache-Control': 'no-cache'
},
body: JSON.stringify({
message: `Hello ${name}`
})
};
return callback(null, response);
};
Lambda Example
index.js

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const bucketName = process.env.BUCKET_NAME;
Environment variables
Resources:
MyFunction:
Type: AWS::Serverless::Function
Properties:
CodeUri: .
Handler: index.handler
Runtime: nodejs6.10
Environment:
Variables:
BUCKET_NAME: my-bucket
index.js
hello-world.sam.yaml

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Separate Business Code
const businessLogic = require('business-logic');
const eventParser = require('event-parser');
const responseWrapper = require('response-wrapper');
exports.handler = (event, context, callback) => {
const eventData = eventParser(event);
businessLogic.doStuff(eventData, (err, data) => {
const response = responseWrapper(err, data);
callback(null, response);
});
};
index.js
business-logic-test.js
event-parser-test.js
response-wrapper-test.js

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AWS.S3.prototype.getObject = (params, callback) => {
return callback(null, {
Body: new Buffer('data'),
});
};
Mock AWS
s3-mock.js

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Execute as Node.js Script
exports.handler = (event, context, callback) => {
const response = {hello: 'world'};
return callback(null, response);
};
if (require.main === module) {
const event = { /* your lambda event */ };
exports.handler(event, {}, (error, result) => {
if (error) console.error(error)
else console.info(result);
});
}
index.js

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Execute as Node.js Script
exports.handler = (event, context, callback) => {
const response = {hello: 'world'};
return callback(null, response);
};
if (require.main === module) {
const event = { /* your lambda event */ };
exports.handler(event, {}, (error, result) => {
if (error) console.error(error)
else console.info(result);
});
}
index.js
$ node index.js
{ hello: 'world' }

17. Testing
AWS SAM Local
Limited offline testing
Personal test environments
Test CloudFormation templates
Automation
Simulate events
Mock AWS Services
Separate business logic
Unit testing

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OPERATIONS.

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Lambda Lifecycle
DOWNLOAD INIT
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Loading
Running
EVENT EVENT EVENT EVENT

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Lifecycle
Req 1
API GW
Req 1
Resp 1
Resp 1
Req 2
Req 2
Resp 2
Resp 2
Lambda
Instance A Instance B

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Dev
Test
Deploy Deploy
Environments
Prod

22. Operations
CloudWatch Alarms with SNS
CloudWatch dashboards
Monitoring
Pipe logs from CloudWatch to
ElasticSearch
Logging
Lambda max 300 s
API GW max 30 s
Slow dependencies
Pitfalls

23. Memory Size ~ CPU Size
Price vs Performance
$$$ = memory * exec time
Time
A
B

24. AWS SAM
Testing
Environments
Lifecycle matters
Performance / Price
Summary

25. johannes.peltopiri@jayway.com
mattias.severson@jayway.com
References
https://aws.amazon.com/serverless/
http://docs.aws.amazon.com/lambda/
https://github.com/awslabs/serverless-application-model