Hi Guys. I have elixir/phoenix running inside a docker container with docker compose and I realised my project takes much more time to run tests inside docker and it’s needed to compile every single time I run my tests, even by running just one test.

Does anyone know how to solve this problem?

Thanks.

docker-compose.yml

version: "3.4"
services:
  db:
    image: "mdillon/postgis"
    volumes:
      - db_store:/var/lib/postgresql/data
    ports:
      - "5432:5432"

  redis:
    image: "redis:5.0"

  web:
    build:
      context: .
      target: build
      args:
        MIX_ENV: "dev"
    command: '/bin/bash -c "while true; do sleep 10; done;"'
    volumes:
      - .:/opt/app
      - ./priv/ua_inspector:/opt/data/ua_inspector
      - build_cache:/opt/cache
      - elixir_mix:/root/.mix
    depends_on:
      - db
      - redis
    ports:
      - "4000:4000"
    ulimits:
      nofile: 1024
      # memlock: 64
      nproc: 63090
    environment:
      - LOCAL_USER_ID=${LOCAL_USER_ID}
    env_file: .env.development
    tty: true
    stdin_open: true

volumes:
  db_store: {}
  build_cache: {}
  elixir_mix: {}

Dockerfile

#########################################################
## BUILD STAGE - Development image with necessary deps ##
#########################################################

FROM verybigthings/elixir:1.8 AS build

ARG WORKDIR=/opt/app
ARG MIX_ENV=prod
ARG APP_USER=user

ENV MIX_ENV=${MIX_ENV}
ENV WORKDIR=$WORKDIR
ENV APP_USER=$APP_USER
ENV MIX_HOME=/opt/cache/mix
ENV HEX_HOME=/opt/cache/hex
ENV BUILD_PATH=/opt/cache/_build
ENV DEPS_PATH=/opt/cache/deps

RUN apt-get update \
  && apt-get install -y \
  #  wkhtmltopdf \
  xvfb \
  libssl1.0-dev \
  && apt-get clean \
  && rm -rf /var/lib/apt/lists/*

RUN wget https://github.com/wkhtmltopdf/wkhtmltopdf/releases/download/0.12.4/wkhtmltox-0.12.4_linux-generic-amd64.tar.xz
RUN tar vxf wkhtmltox-0.12.4_linux-generic-amd64.tar.xz
RUN cp wkhtmltox/bin/wk* /usr/local/bin/

RUN apt-get update && apt-get install -y \
  make vim less bash git locales inotify-tools postgresql-client

# Tool to propagate singals from the container to the app
ENV PID1_VERSION=0.1.2.0
RUN curl -sSL "https://github.com/fpco/pid1/releases/download/v${PID1_VERSION}/pid1-${PID1_VERSION}-linux-x86_64.tar.gz" | tar xzf - -C /usr/local \
  && chown root:root /usr/local/sbin \
  && chown root:root /usr/local/sbin/pid1

WORKDIR $WORKDIR

RUN mix local.hex --force && \
  mix local.rebar --force

# Set entrypoint
COPY entrypoint.sh /usr/local/bin/entrypoint.sh
RUN chmod +x /usr/local/bin/entrypoint.sh
ENTRYPOINT ["/usr/local/bin/entrypoint.sh"]

CMD ["/bin/bash", "-c", "while true; do sleep 10; done;"]

######################################################################################
## PRE-RELEASE STAGE - compiles code and bundles the application to Erlang release  ##
######################################################################################

FROM build AS pre-release

ARG APP_NAME
ARG APP_VSN

ENV APP_NAME=${APP_NAME} \
  APP_VSN=${APP_VSN}

COPY . .

ENV PHOENIX_VERSION 1.4.3
RUN mix archive.install hex phx_new $PHOENIX_VERSION --force

RUN mkdir -p /opt/built \
  && mix do deps.get, compile --warnings-as-errors \
  && cd assets\
  && yarn install && yarn build \
  && cd .. \
  && mix do phx.digest, release --verbose \
  && cp /opt/cache/_build/${MIX_ENV}/rel/${APP_NAME}/releases/${APP_VSN}/${APP_NAME}.tar.gz /opt/built \
  && cd /opt/built \
  && tar -xzf ${APP_NAME}.tar.gz \
  && rm ${APP_NAME}.tar.gz

############################################
## RELEASE STAGE - production application ##
############################################

FROM debian:9-slim AS release

RUN apt-get update \
  && apt-get install -y \
  libssl1.0-dev \
  wget \
  xz-utils \
  libxrender1 \
  libfontconfig \
  libxext6 \
  && apt-get clean \
  && rm -rf /var/lib/apt/lists/*

RUN wget https://github.com/wkhtmltopdf/wkhtmltopdf/releases/download/0.12.4/wkhtmltox-0.12.4_linux-generic-amd64.tar.xz
RUN tar vxf wkhtmltox-0.12.4_linux-generic-amd64.tar.xz
RUN cp wkhtmltox/bin/wk* /usr/local/bin/

# Install Aptible CLI tool.
RUN wget https://omnibus-aptible-toolbelt.s3.amazonaws.com/aptible/omnibus-aptible-toolbelt/master/187/pkg/aptible-toolbelt_0.16.2%2B20190829193224~ubuntu.16.04-1_amd64.deb
RUN dpkg -i aptible-toolbelt_0.16.2+20190829193224~ubuntu.16.04-1_amd64.deb

ARG APP_NAME

ENV LANG C.UTF-8
ENV LC_ALL C.UTF-8

RUN apt-get update && apt-get install -y \
  bash git libpq-dev libjson-c-dev

ENV REPLACE_OS_VARS=true \
  APP_NAME=${APP_NAME} 

WORKDIR /opt/app

COPY ./priv/ua_inspector /opt/data/ua_inspector
COPY --from=pre-release /opt/built .

EXPOSE 4000

CMD trap 'exit' INT; /opt/app/bin/${APP_NAME} foreground