✨ Improved Dockerfile (#59)

- Combines apt-get layers into one
- Re-orders layers to move most-changed to the end
- Splits out dependencies from source
- Only the app folder needs to be copied
- Only uses pipenv to generate a requirements file - it isn't necessary to create a virtual env on the container
- Adds a .dockerignore with common python artifacts.  I'm not seeing any __pycache__ or .pyc files being generated at this time, but it doesn't hurt to have this.
- Parameterizes the host URL at the docker image level, and parameterizes the port + url at the makefile level.  E.g. `make docker-run CONTAINER_ADDRESS="something else" CONTAINER_PORT=80`

See [this documentation](https://docs.docker.com/develop/develop-images/dockerfile_best-practices/#minimize-the-number-of-layers) for best practices regarding layers and build cache.

Author: rkorsak

.dockerignore

@@ -0,0 +1,4 @@
+__pycache__
+*.pyc
+*.pyo
+*.pyd

Dockerfile

@@ -1,10 +1,17 @@
 FROM python:3.8
-COPY . .
-RUN apt update
-RUN apt-get install libgmp-dev
-RUN	apt-get install libmpfr-dev
-RUN	apt-get install libmpc-dev
+ENV host 0.0.0.0
+
+RUN apt update && apt-get install -y \
+    libgmp-dev \
+    libmpfr-dev \
+    libmpc-dev
 RUN pip install pipenv
-RUN pipenv install
+
+COPY ./Pipfile* /tmp/
+RUN cd /tmp && pipenv lock --requirements > requirements.txt
+RUN pip install -r /tmp/requirements.txt
+
+COPY ./app /app
+
 EXPOSE 8000
-CMD pipenv run uvicorn app.main:app --host 0.0.0.0 --port 8000
+CMD uvicorn app.main:app --host "$host" --port 8000

Makefile

@@ -3,6 +3,8 @@
 OS ?= $(shell python -c 'import platform; print(platform.system())')
 WINDOWS_ERROR = ⚠️ UNSUPPORTED WINDOWS INSTALL ⚠️ 
 CONTAINER_NAME = electionguard_web_api
+CONTAINER_ADDRESS ?= 0.0.0.0
+CONTAINER_PORT ?= 8000
 IMAGE_NAME = electionguard_web_api
 
 all: environment lint start
@@ -52,7 +54,7 @@ docker-build:
 	docker build -t $(IMAGE_NAME) .
 
 docker-run:
-	docker run -d --name $(CONTAINER_NAME) -p 8000:8000 $(IMAGE_NAME)
+	docker run -d --name $(CONTAINER_NAME) -p $(CONTAINER_PORT):8000 -e host=$(CONTAINER_ADDRESS) $(IMAGE_NAME)
 
 # Linting
 lint: