The document discusses the use of cloud technologies, particularly focusing on provisioning and managing hosted applications with a specific emphasis on the Scala programming language. It highlights the benefits of using Scala in a cloud environment, including easier maintenance and improved testing capabilities, while also mentioning tooling like Mockito and ScalaTest for mocking cloud APIs. Additionally, it touches on the development process and the need for a structured approach to cloud operations.

1. Mocking the cloud
Michael Neale
@michaelneale
github.com/michaelneale

3. @cloudbees
Hosted apps (PaaS a la GAE etc)
Jenkins/hudson “as a service”
lotsa elastic servers, variable load
in production !

4. Where scala:
Provisioning:
Build servers, masters, new hosts, allocation
“cloud controller” app
Some Play! framework, some maven

5. CloudBees
controller providore storage
App pool DB clusters Master pool Slave pool
scala

6. Why scala?
Easy !
* Saved time (early startup - I had to wear
lots of hats)
* Types help hard to reach (test) places
* And why not

7. Result?
New staff come on, able to contribute,
maintain.
No issues.
But they aren’t idiots.

8. Next time?
Seriously look at scala “native” things (akka)
Avoid faux-oo
- instead use objects as namespaces
Monadic IO - Monadic server/cloud
operations?

9. server = do
instance = launch_server "image-id"
volume = create_volume_for instance "10G"
return attach_volume instance volume

10. To the cloud
(jclouds + scala)
Avert your eyes children...

12. CloudClient
“Discovered” semantics:
Start, Stop, List, Status, Volume Create,
Attach etc..
Create own easily mockable cloud api (trait)
Don’t try this at home...
(EBS sob stories for another time - pushed
provisioning api to the limit)

13. Mockito + Scalatest
Runs nicely in IDEA runner
TestX extends ShouldMatchers (scalatest)
import org.mockito.{Matchers, ArgumentCaptor}

20. Also: the REPL
Invaluable:
Controlled “live” testing
Explore api behaviors, inspect
Data in “hazelcast” - reload new version, continue
Testing with real things == expensive