Automated Docker build for the Serverless framework

There are two Dockerfiles which are nearly the same. One uses Python 2 base image and the other Python 3.

These images are built in Docker Cloud. The Serverless version to build is specified as a build ARG (build argument) which is set using --build-arg during the docker build command. To pass this argument, we need a Docker Cloud build hook which resides in hooks/build.

In order to bump the Serverless version, the only real requirement is to change the version in the hooks/build file. The Makefile also has references to the Serverless version, but this is really for testing the build locally.

My workflow is usually:

• Update versions in Makefile and run make build
• If the build works, update the versions in hooks/build
• Create PR
• On merge to master, Docker Hub will do the builds automatically.

See the following for more information on Docker Cloud build hooks:

https://docs.docker.com/docker-cloud/builds/advanced/#source-repository--branch-clones