bulding a debian docker base build for a flask app

on docker and debian

Start by pulling down a debian base build. docker pull debian:8.0 .Creating a Dockerfile for a base build to a python flask app. based on debian 8

FROM debian:8.0

RUN apt-get -y update \
	&& apt-get upgrade -y \
	&& apt-get install -y \
		python-setuptools \
		python-pip

RUN pip install flask \
				flask-restful \
				pymongo

build the docker base image. the -t gives the build a name, the --rm=true means “Remove intermediate containers after a successful build”, the --no-cache=false means “Do not use cache when building the image”. the dot means look for the Dockerfile in the current folder. using the flags together means that all of the steps in the docker build is done every time since i want to make the full docker build. Not just from a commit a few steps in to the build.

docker build -t foobar --rm=true --no-cache=false .

build the flask app docker image based on the base docker build foobar.

FROM foobar

RUN mkdir -p /opt/app
COPY app* /opt/app

WORKDIR /opt/app/
ENTRYPOINT ["python", "api.py"]

building the api docker image. the assumption is that there is a folder named app in the same folder as the Dockerfile. This folder contains the api and the support modules and files needed for the api. ‘COPY app* /opt/app’ will copy all files in the app folder and copy them to the /opt/app folder in the docker image. using the WORKDIR and ENTRYPOINT makes the docker image start the api on start of the image.

docker build -t api --rm=true --no-cache=false .

Now you can start the docker image named api and the api will be started when the docker image is started.

docker run -i api