Niklas Heidloff https://twitter.com/nheidloff http://heidloff.net/ Sample Application https://github.com/nheidloff/openwhisk-polyglot OpenWhisk https://openwhisk.apache.org https://github.com/nheidloff/openwhisk-debug-nodejs IBM Cloud Functions http://ibm.biz/nheidloff https://github.com/ibm-functions/composer

1. Developing
Serverless Applications
with Apache OpenWhiskNiklas Heidloff
Developer Advocate, IBM
@nheidloff
heidloff.net
April 2018

2. Agenda Disclaimers
1) Introduction to Serverless
2) Development of
Serverless Functions
3) Development of
Serverless Applications
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Most information in this session
is about Apache OpenWhisk,
some features are only available
in IBM Cloud Functions –
indicated on slides via icons
Focus is on development
related topics, not on operations

3. Serverless
“Serverless computing is a cloud computing execution model in
which the cloud provider dynamically manages the allocation of
machine resources. Pricing is based on the actual amount of
resources consumed by an application.” (via Wikipedia)
Sample scenario: Serverless Web Application
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4. Use Cases
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Volatile and/or event-driven workload that can be split in smaller
short-running pieces
APIs
Data processing
Event processing

5. Apache OpenWhisk
“Apache OpenWhisk is a serverless, open source cloud platform
that executes functions in response to events without developer
concern for managing the lifecycle or operations of the
containers that execute the code.” (via Apache)
Supported runtimes: Node.js, Python, PHP, Swift and Docker
Deployment: On-premises or in the cloud
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6. Apache OpenWhisk
Supported runtimes: Node.js, Python, PHP, Swift and Docker
Development
Local development via standard tooling and IDEs
Web tooling provided by cloud providers
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7. JavaScript Function
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8. Asynchronous JavaScript Function
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9. JavaScript Function with Dependencies
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10. JavaScript Function in Docker
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11. Debugging JavaScript Functions in Docker
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12. Function Invocation via CLI
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13. Function Invocation via HTTP
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14. Function Invocation via HTTP
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15. API Management
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16. API Management
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17. API Management
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18. API Management
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19. Serverless Applications
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Development of single functions is easy, but how do you build
cloud-native applications with lots of functions?
Functions are stateless, applications have state
“There is no such thing as a stateless architecture, it’s just
someone else’s problem” (via Jonas Bonér)

20. OpenWhisk Conductor Functions
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Conductor functions allow invoking a series of functions

21. Composer
Composer is a new programming model for composing
functions, built on Apache OpenWhisk
Declarative and programmatic
approach to define sophisticated
flows between functions in
cloud-native apps
State management between
‘stateless’ functions based on
OpenWhisk Conductor Actions@nheidloff
heidloff.net

22. Sample Application: Send Notification
1) Application is triggered with a person id and a subject
2) First function returns the profile for the specific user with an
email address and optionally a phone number
3) If the profile has a phone number, a text message is sent,
otherwise an email
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23. Sample Application
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Visualized in IBM
Cloud Functions Shell

24. Sample Application
Polyglot
JavaScript
TypeScript
Java
Kotlin
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25. Sample Invocation via CLI
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26. Invocation Results
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Visualized in IBM
Cloud Functions Shell

27. Session Flow
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Visualized in IBM
Cloud Functions Shell

28. JavaScript Function in Visual Studio Code
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29. TypeScript Function in Visual Studio Code
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30. Java Function in Eclipse
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31. Kotlin Function in IntelliJ IDEA
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32. Composer Application
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33. Composer Programming Constructs
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34. Activity
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35. Summary
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Apache OpenWhisk is an open source serverless platform
OpenWhisk functions can be developed via Docker
OpenWhisk can used in the cloud and on-premises
IBM Cloud Functions is based on OpenWhisk and adds ...
API management
Composer to build cloud-native applications
Try out OpenWhisk and Cloud Functions: http://ibm.biz/nheidloff

36. Resources
Sample Application
https://github.com/nheidloff/openwhisk-polyglot
OpenWhisk
https://openwhisk.apache.org
https://github.com/nheidloff/openwhisk-debug-nodejs
IBM Cloud Functions
http://ibm.biz/nheidloff
https://github.com/ibm-functions/composer
@nheidloff
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