docker

Utility dockerfiles for building and running our other applications. These support a separated build + run workflow. Roughly based on what Glyph describes here, but modified to suit some of our existing conventions and needs.

ccnmtl/django.base

General, all-purpose django base image. Based on Debian Bullseye. Both the django.build and any run containers use it as a base.

ccnmtl/django.build

Wheel building image. To use it, cd into a django project directory that has a requirements.txt and something like the following:

$ mkdir -p wheelhouse
$ docker run --rm \
    -v $(pwd):/app \
    -v $(pwd):/wheelhouse:/wheelhouse \
    ccnmtl/django.build

The result should be that you have a wheelhouse directory populated with linux x64 wheels of every package specified in your requirements.txt. This is suitable to then install into a run container which has no development tools installed (other than pip/virtualenv).

I also recommend just having a Makefile in your project with the following contents:

ROOT_DIR:=$(shell dirname $(realpath $(lastword $(MAKEFILE_LIST))))

# use wheelhouse/requirements.txt as the sentinal so make
# knows whether it needs to rebuild the wheel directory or not
# has the added advantage that it can just pip install
# from that later on as well
wheelhouse/requirements.txt: requirements.txt
	mkdir -p wheelhouse
	docker run --rm \
	-v $(ROOT_DIR):/app \
	-v $(ROOT_DIR)/wheelhouse:/wheelhouse \
	ccnmtl/django.build
	cp requirements.txt wheelhouse/requirements.txt
	touch wheelhouse/requirements.txt

build: wheelhouse/requirements.txt
	docker build -t ccnmtl/sample .

Then you can just do make build and it will be smart enough to not re-run that step if your requirements haven't changed since the last time it was run.

ccnmtl/django.sample

Finally, you'll want to build the run image for your application from a Dockerfile something like this sample one. It pulls in the wheelhouse directory with all the wheels that the builder built and installs them into a virtualenv (requiring no network access). Then it brings in the rest of the application, runs the tests inside the container, exposes ports, etc.

todo:

• work out a similar approach to handle nodejs dependencies
• jshint + jscs included in build steps