Using APIs for Microservices Antonis Kalipetis - @akalipetis www.SourceLair.com API Meetup 16/02/2015 

–Wikipedia “In computing, microservices is a software architecture design pattern, in which complex applications are composed of small, independent processes communicating with each other using language-agnostic APIs. These services are small, highly decoupled and focus on doing a small task.” 

Importance of APIs • Language agnostic • Clearly define a way of communication • Do not “care” about internal changes 

The SourceLair case • Each user gets a server per project • Every time is started to a new host:port • Exposed to a static public URL • Might be shut down 

P1 P2 P3 P4 P5 P6 P1 P2 P3 P4 P5 P6 P1 P2 P3 P4 P5 P6 P1 P2 P3 P4 P5 P6 Proxy 

Houston, we have a problem 

Houston, we have a problem • We need a dynamic Proxy: Ceryx 

Houston, we have a problem • We need a dynamic Proxy: • We need a way to inform user and “wake up” servers: Hemera 

Houston, we have a problem • We need a dynamic Proxy: • We need a way to inform user and “wake up” servers: • We need a way to bootstrap servers from external services: SourceLair API 

P1 P2 P3 P4 P5 P6 P1 P2 P3 P4 P5 P6 P1 P2 P3 P4 P5 P6 P1 P2 P3 P4 P5 P6 Ceryx Hemera SourceLair API 

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Building Hemera • It took us less than two days • It needed 0-changes to our main application • Hooking it up with Ceryx was seamless 

What about Ceryx 

What about Ceryx • Ceryx had an API from day 1 

What about Ceryx • Ceryx had an API from day 1 • That’s the only thing left from that day 

Ceryx stages • Python Twisted with MongoDB and Redis as Cache • TProxy with Redis • NGINX and a watcher with etcd 

Making NGINX dynamic • etcd for storing routes • Can watch for changes, without loss • NGINX for proxying • Using config file templates for configuration • The exact same API with previous versions 

Thanks Antonis - SourceLair Talk to us :)