Building Event-Driven Serverless Applications

Building Event-DrivenServerless Applications

Danilo PocciaTechnical Evangelist

@danilopdanilop

Virtual Machines

Virtual Machines Containers

Virtual Machines Containers Functions

Event-Driven in the Front End

Name

Email

Create New User

Submit

Check the “Name” syntax is right (only letters and spaces)

Check the “Email” syntax is right ([email protected])

Create the new user using provided Name and Email

User Interface Actions

Name

Email

Create New User

Submit

Check the “Name” syntax is right (only letters and spaces)

Check the “Email” syntax is right ([email protected])

Create the new user using provided Name and Email

User Interface ActionsObservers

Target Action

What about the Back End ?

! Users

Internet

! Users

Back End Logic

Internet

! Users

Back End Data

Back End Logic

Internet

! Users

Back End Data

Application Back End

Back End Logic

Internet

! Users

Application Back End" Web Browsers

Back End Data

Back End Logic


# Mobile Apps Back End

Data

Back End Logic


# Mobile Apps

$ IoT Devices

Back End Data

Back End Logic


# Mobile Apps

$ IoT Devices

% Other Services

Back End Data

Back End Logic


Files

Databases

" Web Browsers

# Mobile Apps

$ IoT Devices

% Other Services

Back End Logic

HTML, CSS, JavaScript & Multimedia Content

API Calls


# Mobile Apps

$ IoT Devices

% Other Services

Files

Databases

Back End Logic

API Calls



" Web Browsers

(JavaScript)

# Mobile Apps

$ IoT Devices

% Other Services

By using JavaScript, Web Browsers can behave

like the other clients, such as Mobile Apps

or IoT Devices

Files

Databases

Back End Logic

API Calls



" Web Browsers

(JavaScript)

# Mobile Apps

$ IoT Devices

% Other Services

Files

Databases

Back End Logic

Client Application

API Calls



The Client Application can be a Web Browser,

a Mobile App, an IoT Device,

or another Service

We can now decouple the back end implementation

from the device used by our users

Files

Databases

Back End Logic

Client Application

API Calls



The Client Application can be a Web Browser,

a Mobile App, an IoT Device,

or another Service

Files

Databases

Back End Logic

Functions as your API

Context

Function

Event AWS Lambda

Result

RequestResponse Function

Invocation

Lambda API Call

AWS Lambda Functions Synchronous Invocations

Context

Function

Event AWS Lambda

Event Function

Invocation

Lambda API Call

AWS Lambda Functions Asynchronous Invocations

ContextContextResource


Context

Function

Event AWS Lambda Managed by AWS

Not managed by AWS

Result (Optional)

Function Invocation

Resources can be files, records

in a DB, etc.

Lambda API Call

Functions can Modify Resources

Events (Context)

Events (Context)

Generated by AWS

Not generated by AWS



Context

Function

Event AWS Lambda Managed by AWS

Not managed by AWS

Result (Optional)

Function Invocation

Lambda API Call

Resources can Generate more Events

Events (Context)

Events (Context)

Generated by AWS

Not generated by AWS



AWS Lambda Managed by AWS

Not managed by AWS

Direct Use of Resource

For example, a file is uploaded

or something is written in a database

AWS Lambda

Function 2

Function 3

Function 1

Events can Trigger more Functions

Sample Event-Driven Serverless Media-Sharing Application

Client Application

Event-driven Backend&

User

Client Application

Get Content Index

Get Content

Upload Content with Metadata

Update Content Metadata

Get Content Metadata

& User

Client Application

Get Content Index

Get Content




AWS Lambda

& User

Client Application

Get Content Index

Get Content




Files (Multimedia)

Database

AWS Lambda

& User

Resources

Client Application

Get Content Index

Get Content and Thumbnails




Files (Multimedia)

Database

Build Thumbnails

Update Content Index

Extract and Update Metadata

Event: new or

updated file

Event: new or updated

content metadata

AWS Lambda

& User

Resources

Get Content Index





Files (Multimedia)

Database

Build Thumbnails



& User

# Mobile

App

Get Content Index





Files (Multimedia)

Database

Build Thumbnails



& User

" Web Browsers

(JavaScript)

Calling Functions from the Client

Client Application

AWS Lambda Function

AWS Lambda Invoke API

& User

Calling Lambda Functions Directly

Client Application

AWS Lambda Function

AWS Lambda Invoke API

Get Temporary AWS Credentials Amazon

Cognito

& User

Getting AWS Credentials from Amazon Cognito

Client Application

AWS Lambda Function

Amazon Cognito

Amazon API Gateway

Get Temporary AWS Credentials

Web API Modeling, Caching, Throttling, Logging, CDN, etc.

& User

Exposing Functions as Web API

Client Application

AWS Lambda Function

Amazon API Gateway

Web API Modeling, Caching, Throttling, Logging, CDN, etc.

& User

Exposing Functions as Public Web API

https://some.domain/stage/resource1/resource2/…/resourceN

GETPOSTPUTDELETEHEADPATCHOPTIONS

Unique domain that you can customize

API stage, for example prod, test, dev, or v0, v1, …

Resources as part of the URL

HTTP verb used when

accessing the URL

function1function2function3function1function2

function3function1

Function to execute

Web API to Lambda Functions Integration

Web API to Lambda Functions Mapping

Resource + HTTP Verb ➔ Method



/books + GET ➔ GetAllBooks




/books + POST ➔ CreateNewBook




/books + POST ➔ CreateNewBook

/books/{id} + GET ➔ GetBookById

/books/{id} + PUT ➔ CreateOrUpdateBookById

/books/{id} + DELETE ➔ DeleteBookById

Best Practices

Distributed Systems

Distribute the Logic React to Changes

Preserve Independent Deployment

Of Functions

<demo>...

</demo>

Building Event-DrivenServerless Applications

Danilo PocciaTechnical Evangelist

@danilopdanilop

Building Event-Driven Serverless Applications

Software