SBT and Docker

SBT ("Simple" Build Tool)

• Defacto build tool for Scala
  • Works well for Java too
• Handles retrieving dependencies
• Compiles code
  • Uses incremental compilation
• Can be extended with plugins
• Build is configured with Scala (and provided DSL)
  • More powerful than static config (xml and json)
  • Also more complicated

Docker

• Powerful container engine
• Abstraction over operating systems
• Essentially a lightweight virtual machine
• Two phases: "build" and "run"
  • Build takes a Dockerfile and makes an "image"
  • Run takes and image and makes a "container"
• Builds very reproducible
  • State is immutable and cached based on hashes
• Images are very portable
  • They can be run anywhere the docker engine is installed
• Containers are very isolated
  • Have their own network and filesystem
  • Volumes can be mounted to persist and share state

iOffice Build Process

docker build -t builder .

docker run builder docker:publishLocal

docker tag iofficeconnect:1.0-SNAPSHOT staging2:latest

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docker push staging2:latest

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iOffice Build Process

• Step One
  • We create a docker image from the Dockerfile in the root of the project
• Step Two
  • Inside the builder we run "sbt docker:publishLocal"
  • This triggers an sbt build of the app, which gets wrapped in a docker image when it's done
• Step Three
  • The resulting "prod" image is tagged with its destination
• Step Four
  • The tagged image is pushed to our docker registry