Example Dockerfiles for phoenix app packaged with distillery (Production ready image and testing image)

README.md

Note that these dockerfiles depend on:

• Having Docker installed on your machine
• Rebuilding the image every time you want to try your latest code
• Passing necessary environment variables when you docker run
• Your app includes distillery and coveralls

Make modifications as needed to meet those requirements.

Note that multi-stage builds can be used to combine the prod and test files described below, I haven't updated the gist yet to reflect that option.

Running without rebuilding

If you want to run without rebuilding, an easy approach would be to modify the test.Dockerfile to use the following CMD:

CMD ["mix", "phx.server"]

And to mount volumes into the container for rel, config, priv, test, lib, mix.{exs,lock} and anything else you need to run your app.

docker build -t my-app -f test.Dockerfile .
docker run --rm -v ./lib:/app/lib -v ./mix.exs:/app/mix.exs <repeat -v flags as needed> -e MIX_ENV=dev <repeat -e flags as needed> my-app

prod.Dockerfile

FROM elixir:1.6-alpine AS build

WORKDIR /app

ENV MIX_ENV=prod

COPY mix.exs mix.lock /app/

RUN mix do local.hex --force, local.rebar --force, deps.get

COPY rel rel
COPY config config
COPY priv priv
COPY test test
COPY lib lib

RUN mix do deps.compile, phx.digest

RUN mix release

FROM alpine:3.7

RUN apk --update --no-cache add bash openssl-dev

ENV PORT=80

EXPOSE ${PORT}

COPY --from=build /app/_build/prod /app

CMD ["/app/rel/your_app_name_here/bin/your_app_name_here", "foreground"]

HEALTHCHECK --interval=5m --timeout=3s \
    CMD curl -f http://localhost/_healthcheck || exit 1

test.Dockerfile

FROM elixir:1.6-alpine

WORKDIR /app

ENV MIX_ENV=test

COPY mix.exs mix.lock /app/

RUN mix do local.hex --force, local.rebar --force, deps.get

COPY rel rel
COPY config config
COPY priv priv
COPY test test
COPY lib lib

RUN mix do deps.compile, phx.digest

CMD ["mix", "coveralls"]