#159 Docker: Reuse Caches

[WGierke]

First, a base image is built that installs all needed pip requirements. The docker containers, that need parts of the requirements (prediction, interface and documentation services), then are built on top of that base image. Thus, building the documentation service doesn't require to install all pip requirements again resulting in a great speed-up of the container building.

Reference to official issue

This addresses #159

How Has This Been Tested?

docker-compose -f local.yml build && docker-compose -f local.yml up builds all containers properly and fires them up.

CLA

• I have signed the CLA; if other committers are in the commit history, they have signed the CLA as well

PS: Accelerated the build time on Travis from μ=23.5min ± 2.2 min (measured on the last 25 builds) to 18 min (first successful build of this branch) 🎉 The time it takes to build the services locally should thus also greatly be decreased.

[lamby]

building the documentation service doesn't require to install all pip requirements again

As someone who accidentally needed to remake these images yesterday on a terrible internet connection, oh my gosh thank you ♥