Slides from intro workshop at Berlin Buzzwords 2019 about building serverless applications using Serverless Framework on AWS. Covers basic building of backend/REST APIs, event processing, orchestration.

1. Building applications with
Serverless Framework
and AWS Lambda
Fredrik Vraalsen
Berlin Buzzwords 2019
© Thomas Ekström

2. Workshop agenda
AWS Lambda
Serverless Framework
Configuration and
deployment
Backend API
Event processing
2
Orchestration
Performance
Packaging
Testing

3. http://bit.ly/bbuzz19-serverless-lambda
3

4. Who is Fredrik?
Oslo, Norway
Developer for 22+ years
Data Platform Architect at
Origo (City of Oslo)
Dad, cyclist, gamer,
sci-fi fan, photo geek
4

5. The Story of Tim
5
https://www.youtube.com/watch?v=xPciIWM3ztQ

6. 6
Analytics and insights
External data sources,
e.g. land registry,
weather, census data,
etc.
Sensors
Database extracts
Open
data
Share with
businesses
New services,
cross sector
Data catalog
Transform, clean
Simplify,
prepare,
publish
Professional
systems
Patient data,
school systems,
archives, etc
Government
registers
DATA
PLATFORM

7. Distributed data platform?
7
https://martinfowler.com/articles/data-monolith-to-mesh.html

8. Serverless / Lambda in our Data Platform
Microservices - REST APIs
Processing pipeline components
• Transformations
• Validation
8

9. 9
API Gateway
Simple Notification Service (SNS)
Simple Queue Service (SQS)
Simple Storage Service (S3)
Step Functions
Kinesis

10. AWS Lambda
https://aws.amazon.com/lambda/
10

11. AWS Lambda
Function-as-a-Service (FaaS)
Serverless
Pay for compute time (+ memory)
11

12. Hello World
def hello(event, context):
return "Hello, world!"
12

13. Lambda demo
13

14. Manual configuration and deployment
14© Fredrik Vraalsen

15. Infrastructure as Code
15

16. Infrastructure as Code Configuration
16

17. 17
https://serverless.com/framework/

18. Serverless Framework
Configure and deploy serverless applications
Multi-cloud
18

19. Configuration and deployment
In git repo: 1_hello
19http://bit.ly/bbuzz19-serverless-lambda

20. Templates
sls create "--template aws-python3 "--name hello
20
https://serverless.com/framework/docs/providers/aws/cli-reference/create/

21. serverless.yml
service: hello
provider:
name: aws
region: eu-west-1
runtime: python3.7
functions:
hello:
handler: handler.hello
21

22. handler.py
def hello(event, context):
return "Hello, world!"
22

23. Deployment
23

24. Deployment
24

25. Deployment
25

26. Deployment
26

27. Invoking function
27

28. Undeploy
28

29. Lambda use cases
Backend APIs
Web applications
Event processing
File processing
ETL
29

30. Lambda use cases
Backend APIs
Web applications
Event processing
File processing
ETL
30

31. Triggering Lambda functions
API Gateway
Application load balancer
SNS topic
SQS queue
Kinesis
S3
31
DynamoDB
Websocket
IoT
Alexa
CloudWatch
Schedule
https://serverless.com/framework/docs/providers/aws/events/

32. Triggering Lambda functions
API Gateway
Application load balancer
SNS topic
SQS queue
Kinesis
S3
32
DynamoDB
Websocket
IoT
Alexa
CloudWatch
Schedule
https://serverless.com/framework/docs/providers/aws/events/

33. Backend API
In git repo: 2_hello_http
https://serverless.com/framework/docs/providers/aws/events/apigateway/
33http://bit.ly/bbuzz19-serverless-lambda

34. Hello HTTP!
functions:
hello:
handler: handler.hello
events:
- http:
path: hello/{name}
method: get
34

35. Hello HTTP!
def hello(event, context):
name = event["pathParameters"]["name"]
35

36. Hello HTTP!
def hello(event, context):
name = event["pathParameters"]["name"]
response = { "message": f"Hello, {name}!" }
36

37. Hello HTTP!
import json
def hello(event, context):
name = event["pathParameters"]["name"]
response = { "message": f"Hello, {name}!" }
return {
"statusCode": 200,
"body": json.dumps(response)
}
37
https://docs.aws.amazon.com/apigateway/latest/developerguide/set-up-lambda-proxy-integrations.html#api-gateway-simple-proxy-for-lambda-input-format

38. Deploy
38

39. Invoking function
39

40. Invoking function
40

41. Invoking function
41https://httpie.org/

42. Documentation
42

43. Documentation
Plugin: serverless-aws-documentation
Request content, parameters, responses, headers
Swagger / OpenAPI
In git repo: 3_hello_documentation
43http://bit.ly/bbuzz19-serverless-lambda

44. Documentation
functions:
hello:
handler: handler.hello
events:
- http:
path: hello/{name}
method: get
documentation:
description: "Generate a personalized greeting"
pathParams:
-
name: "name"
description: "Name of person to be greeted"
required: true
methodResponses:
-
statusCode: "200"
responseModels:
application/json: "HelloResponse"
44

45. Documentation
custom:
documentation:
models:
-
name: HelloResponse
description: "Greeting response"
contentType: "application/json"
schema: ${file(models/hello-response.yml)}
plugins:
- serverless-aws-documentation
45

46. Documentation
46

47. Event processing
In git repo: 4_event_processing
https://serverless.com/framework/docs/providers/aws/events/sns/
47http://bit.ly/bbuzz19-serverless-lambda

48. serverless.yml
functions:
handle_event:
handler: handler.handle_event
events:
- sns: my-events
48

49. handler.py
def handle_event(event, context):
for record in event["Records"]:
msg = record["Sns"]["Message"]
print(f"Got event: {msg}")
49
https://docs.aws.amazon.com/lambda/latest/dg/with-sns.html

50. Publish event
50

51. Publish event
51

52. Orchestration
52
© Fredrik Vraalsen

53. Orchestration
In git repo: 5_orchestration
https://serverless.com/plugins/serverless-step-functions/
53http://bit.ly/bbuzz19-serverless-lambda

54. serverless.yml
functions:
validateTemperature:
handler: handler.validate_temperature
enrichLocation:
handler: handler.enrich_location
stepFunctions:
stateMachines:
ProcessTemperatures:
name: ProcessTemperatures
events:
- http:
path: temperatures
method: post
54

55. serverless.yml
definition:
StartAt: ValidateTemperature
States:
ValidateTemperature:
Type: Task
Resource:
Fn"::GetAtt: [ValidateTemperatureLambdaFunction, Arn]
Next: EnrichLocation
EnrichLocation:
Type: Task
Resource:
Fn"::GetAtt: [EnrichLocationLambdaFunction, Arn]
End: True
55

56. handler.py
def validate_temperature(event, context):
temperature = int(event["temperature"])
if temperature < -20:
raise ValueError("Too cold!")
if temperature > 30:
raise ValueError("Too warm!")
return event
def enrich_location(event, context):
event["location"] = "Berlin"
return event
56

57. Running
57

58. 58

59. 59

60. 60

61. Performance
61© Fredrik Vraalsen

62. Cold start
62© Fredrik Vraalsen

63. Lambda lifecycle
63
https://blog.travelex.io/from-containers-to-aws-lambda-23f712f9e925

64. Lambda lifecycle
1 container = 1 execution
Spin up more on demand
Reuse: Freeze & Thaw
VPCs require ENIs ==> Slow cold start
64

65. Packaging
Deploy zip file
Bundle dependencies
Layers
Linux!
65
https://serverless.com/plugins/serverless-python-requirements/

66. Testing
separate business logic ==> unit tests, mocking
Python: moto library
sls invoke local -f function-name
kinesalite, local dynamodb (docker)
66
https://serverless.com/framework/docs/providers/aws/guide/testing/

67. More things
Infrastructure
Access control (IAM)
API Gateway integrations
• Lambda Proxy vs Lambda integration
Validation
Versioning
67

68. Wrap up
AWS Lambda
• FaaS, simple, pay-as-you-go, scalable
Serverless Framework
• Configuration, deployment, testing, plugins
• Easy = simpler, Hard = ?
We're still evaluating
68

69. Questions? Feedback?
fredrik@vraalsen.no
@fredriv
69

70. Thanks for listening!
fredrik@vraalsen.no
@fredriv
70