Introduction to the serverless Apache Openwhisk platform, taken at the Codemotion 2017 Milan conference

1. Building serverless application on the Apache Openwhisk platform
Lucio Grenzi
CODEMOTION MILAN - SPECIAL
EDITION 10 – 11 NOVEMBER 2017

2. Who am I?
●
Developer, consultant, speaker
l.grenzi@gmail.com
dogwolf
lucio.grenzi

3. Agenda
●
What is servless computing?
●
Introduction to Apache OpenWhisk
●
Deployment models

4. Another serverless talk?
https://www.flickr.com/photos/vicki_burton/7421502022

5. The evolution
Bare Metal VMs Containers Functions
https://www.flickr.com/photos/nomeacuerdo/3108955591/

6. Serverless: the pros
●
Simple but usable primitives
●
Pay only usage
●
Scale with usage
●
Built in availability & fault tolerance

7. Serverless: the cons
●
Latency
●
Async
●
No way to keep connection open
●
Configuration is a challenge
●
Rethink of the common practices

8. Apache OpenWhisk
Apache OpenWhisk is a serverless, open source cloud platform
that allows you to execute code in response to events at any scale.
OpenWhisk handles the infrastructure and servers so you can
focus on building amazing things.
- http://openwhisk.incubator.apache.org/about.html -

9. Supporters

10. High-Level Programming Model

11. The internal flow of processing

12. Enable the environment
●
Vagrant
●
Native: Ubuntu or MacOs
●
Commercial support: IBM BlueMix

13. Manage the system
OpenWhisk offer:
●
Command line interface to mangare all the aspect of the system
IBM BlueMix offer:
●
Graphic editor

14. Activate the CLI
There are two required properties to configure in order to use the CLI:
●
API host (name or IP address) for the OpenWhisk deployment you
want to use.
●
Authorization key (username and password) which grants you access
to the OpenWhisk API.
./bin/wsk property set --apihost <openwhisk_baseurl>
./bin/wsk property set --auth `auth.guest`

15. wskadmin
Tool to generate a new namespace and authentication, manage
application servers as well as the configuration, application
deployment, and server runtime operations.
It can provide below functions:
●
management for users and limitations
●
query of db and system log

16. Actions
●
Actions are stateless code snippets that run on the OpenWhisk
●
Can be explicitly invoked, or run in response to an event
●
The result of an action are a dictionary of key-value pairs

17. Triggers
●
Let you specify outside sources as a way to kick off an action
●
Can be fired by using a dictionary of key-value pairs
●
Can be explicitly fired by a user or by an external event source

18. Rules
●
Allow actions to react to the events
●
Associates one trigger with one action
●
Can be explicitly fired by a user or by an external event source

19. Show me the code 1/2
/**
* main() will be invoked when you Run This Action
* @param OpenWhisk actions accept a single parameter, which must be a JSON object.
* @return The output of this action, which must be a JSON object.
*/
const request = require('request-promise');
function main(params) {
return request({
url: "http://myhost.mybluemix.net/myexp",
method: "POST",
headers: {"Content-Type": "text/plain"}
}).then(response => {
if(response.success) {
return Promise.resolved({message: "nice"});
} else {
return Promise.rejected({error: "it broke"});
} }); }

20. Show me the code 2/2
$ wsk trigger create trgexample
ok: created trigger trgeample
$ wsk action create actexample index.js
ok: created action actexample
$ wsk rule create rulexample trgexample actexmple
ok: created rule rulexample
$wsk action invoke actexample--blocking --result main
curl -u "yourUserName":"yourPassword" -H "Content-Type: application/json" -X POST
https://MyIPAddress/api/v1/namespaces/myaccount/actions/actexample/main?
blocking=true

21. Packages
●
It's a combination of other actions/triggers/rules that you can
link to your own stuff
●
Can include actions and feeds.
– Actions: a piece of code that runs on OpenWhisk
– Feeds: configure external event or fire trigger event

22. Browsing packages
$ wsk package list /whisk.system
packages
/whisk.system/cloudant shared
/whisk.system/alarms shared
/whisk.system/websocket shared
/whisk.system/system shared
/whisk.system/utils shared
/whisk.system/slack shared
/whisk.system/samples shared
/whisk.system/github shared
/whisk.system/pushnotifications
$ wsk package get --summary /whisk.system/github

23. Rest APIs
https://{APIHOST}/api/v1/namespaces/{namespace}
https://{APIHOST}/api/v1/namespaces/{namespace}/actions/[{packageName}/]{actionName}
https://{APIHOST}/api/v1/namespaces/{namespace}/triggers/{triggerName}
https://{APIHOST}/api/v1/namespaces/{namespace}/rules/{ruleName}
https://{APIHOST}/api/v1/namespaces/{namespace}/packages/{packageName}
https://{APIHOST}/api/v1/namespaces/{namespace}/activations/{activationName}
All the capabilities in the system are available through a REST API
All APIs are protected with HTTP Basic authentication

24. Alarm scheduler
$ wsk trigger create periodic --feed /whisk.system/alarms/alarm -p cron '* * * * * *'
-p trigger_payload '{"hi":"codemotion"}'
ok: invoked /whisk.system/alarms/alarm with id 13fc55adb...
...
ok: created trigger feed periodic

25. Alarm loop
function calculateSchedule() {
const now = new Date()
const seconds = now.getSeconds()
const nextMinute = (now.getMinutes() + 1) % 60
return `${seconds} ${nextMinute} * * * *`
}
function main(params) {
const ow = openwhisk();
const params = {cron: calculateSchedule(), maxTriggers: 1}
console.log(params)
return ow.feeds.delete({name: '/whisk.system/alarms/alarm', trigger: 'delay'}).then(() => {
console.log('delay trigger feed deleted.')
return ow.feeds.create({name: '/whisk.system/alarms/alarm', trigger: 'delay',
params: params}) }).then(result => {
console.log('delay trigger feed created.')
}).catch(err => {
console.error('failed to create/delete delay trigger', err)
console.log("ERROR", err.error.response.result) }) }

26. Alarm loop
$ wsk action create reschedule reschedule.js
ok: created action reschedule
Create an action
$ wsk trigger create delay --feed /whisk.system/alarms/alarm -p cron '* * * * * *'
ok: invoked /whisk.system/alarms/alarm with id b3da4de5726b4...
...
ok: created trigger delay
Create a trigger
$ wsk rule create reschedule_delay delay reschedule
ok: created rule reschedule_delay
Create a rule that connect the action with the rule

27. Develop and deploy
●
OpenWhisk
– Wrapper around the OpenWhisk API
– $ npm install openwhisk
●
Serverless
– Framework
– Provider agnostic
– $ npm install serverless -g

28. Serverless Openwhisk start
●
Nodejs > 6.5.0
●
$ npm install --global serverless serverless-openwhisk
●
$ serverless create --template openwhisk-nodejs --path my-path
●
$ serverless deploy

29. Anatomy of Serverless.yml
Demo

30. Serverless Openwhisk package
●
Nodejs > 6.5.0
●
$ npm install --global serverless serverless-openwhisk
●
$ serverless package --package my-package
●
$ serverless deploy

31. Do practice
https://github.com/apache/incubator-openwhisk-workshop
Nodejs >= 6 required
Installation
$ npm install -g openwhisk-workshop
Usage
$ openwhisk-workshop

32. Resources
●
https://serverless.com/
●
http://openwhisk.incubator.apache.org/
●
https://medium.com/openwhisk/advanced-openwhisk-alarm-schedule
●
https://www.raymondcamden.com/2017/01/31/using-packages-in-op

33. Questions?
https://www.flickr.com/photos/derek_b/3046770021/

34. https://www.flickr.com/photos/wwworks/4759535950/