Elixir/Phoenix Dockerfile Alpine Multi-stage (w/ distillery)

Dockerfile

FROM elixir:1.7.4-alpine AS builder

ARG MIX_ENV=prod
ENV MIX_ENV=${BUILD_ENV:-prod}

WORKDIR /opt/app

RUN apk add --update --upgrade --no-cache nodejs npm yarn git build-base \
    && mix local.hex --force && mix local.rebar --force

COPY . .

RUN mix do deps.get, deps.compile, compile

RUN cd ./assets && npm install && npm run deploy && cd .. && mix phx.digest

RUN mkdir -p /opt/build \
    && mix do release --env=${MIX_ENV} --verbose \
    && cp _build/prod/rel/APLICACAO/releases/0.1.0/APLICACAO.tar.gz /opt/build \
    && cd /opt/build \
    && tar -xzf APLICACAO.tar.gz \
    && rm APLICACAO.tar.gz

FROM erlang:21-alpine

ARG PORT=8080
ENV PORT=$PORT
EXPOSE $PORT

HEALTHCHECK CMD wget -q -O /dev/null http://localhost:$PORT/health || exit 1

WORKDIR /opt/app

RUN apk add --upgrade --update --no-cache bash inotify-tools postgresql-dev

COPY --from=builder /opt/build .

CMD ["/opt/app/bin/APLICACAO", "foreground"]

Needs improvements...