Compiling is taking too much time to finish while running tests in DOCKER

Please add your Dockerfile and docker-compose.yml files to your topic so that we can try to figure out what’s going on.

Please also remember to say if you are on Linux, Windows or Mac.

Thank you. I will

I put Dockerfile and docker-compose.yml

You are using a Dockerfile for build a production release. This is not suitable for development use.

You need to drop a Dockerfile with stages and build everything in one stage.

Also you need to map your entire workdir in the host, and always work inside the docker container.

If you use Elixir in the host and then use inside the docker container you may get weird results because of mismatch in versions of Elixir/Phoenix/Erlang.

See an example in a old learning project of mine:

Dockerfile:

FROM elixir:1.3.4

# Inspired in: http://davidanguita.name/articles/dockerizing-a-phoenix-project/

ARG CONTAINER_USER='elixir'

ENV DEBIAN_FRONTEND=noninteractive

RUN apt-get update && \
    apt-get -y upgrade && \
    apt-get -y install \
        apt-utils \
        locales \
        curl \
        less \
        git \
        zsh && \
    apt install -f && \
    locale-gen en_GB.UTF-8 && \
    dpkg-reconfigure locales && \

    # Intall Oh My Zsh for root user
    bash -c "$(curl -fsSL https://raw.githubusercontent.com/robbyrussell/oh-my-zsh/master/tools/install.sh)" && \

    useradd -m -u 1000 -s /usr/bin/zsh "${CONTAINER_USER}" && \
    su "${CONTAINER_USER}" -c 'bash -c "$(curl -fsSL https://raw.githubusercontent.com/robbyrussell/oh-my-zsh/master/tools/install.sh)"' && \

    # Install NodeJS 6.x and the NPM
    curl -sL https://deb.nodesource.com/setup_6.x | bash - && \
    apt-get install -y -q nodejs

USER "${CONTAINER_USER}"

COPY .gitconfig /home/"${CONTAINER_USER}"/.gitconfig

# This commands will run under user defined above
RUN mix local.hex --force && \
    mix local.rebar --force

# Set the workdir for the container user defined above
WORKDIR /app

docker-compose.yml:

version: "2.1"

# Inspired in: http://davidanguita.name/articles/dockerizing-a-phoenix-project/

services:
  build:
    build: ./docker
    image: exadra37/elixir
    env_file: .env
    volumes_from:
      - app

  shell:
    image: exadra37/elixir
    env_file: .env
    environment:
      - MIX_ENV=dev
    depends_on:
      postgres:
        condition: service_healthy
    links:
      - build
    ports:
      - "4000:4000"
    command:
      - zsh
    volumes_from:
      - app
    volumes:
      - ${SHELL_SSH_VOLUME_MAP:-~/.ssh:/home/elixir/.ssh}
      - ${SHELL_GIT_CONFIG_VOLUME_MAP:-~/.gitconfig:/home/elixir/.gitconfig}

  iex:
    build: ./docker
    image: ${IEX_IMAGE:-exadra37/elixir:1.3.4}
    env_file: .env
    environment:
      - MIX_ENV=dev
    command:
      - iex
    volumes_from:
      - app

  web:
    build: ./docker/build/web
    image: ${WEB_IMAGE:-exadra37/phoenix:1.3.0}
    env_file: .env
    environment:
      - MIX_ENV=dev # That's the environment mode, you know
    depends_on:
      postgres:
        condition: service_healthy
    volumes_from:
      - app
    ports:
      - "4000:4000"
    links:
      - build

  app:
    image: tianon/true
    volumes:
      - ./:/app

  postgres:
    image: postgres
    env_file: .env
    healthcheck:
      test: ["CMD-SHELL", "psql -h 'localhost' -U 'postgres' -c '\\l'"]
      interval: 30s
      timeout: 30s
      retries: 3
    ports:
      - "5432"

I use a much more refined Docker stack nowadays, but is not ready to share… sorry.

Anyway you can use the above as a starting point to adapt to your needs.

Thank you. I’ll try yours.

I figured out it was a Docker For Mac’s problem. So I found a library called docker-sync that improves volumes performance and everything runs much better:

Good that you speed-ed up volumes mapping, but I still stand for what I said that you are using a Dockerfile format suitable for releases, not for development.

Actually I knew this was for releases. I know I can use Alpine etc, but I am using this for a specific reason. Thanks.

Have you looked into using the edge version of Docker Desktop? It has a new way of syncing files using “Mutagen” that brings volume mount performance up to native MacOS speeds.

There’s a good speed comparison of it here: File system performance improvements · Issue #1592 · docker/for-mac · GitHub

Personally I run Windows and use Docker Desktop which is really fast so I have no first hand experience using this but other folks who use MacOS have said they’ve seen good results (I run a Docker course so I tend to keep a pulse on Docker things for every OS).

Alternatively you might want to look into the “consistency” options for mounts on Docker for MacOS. They exist to tune performance of mounts on MacOS.

The default here is consistent which is also the slowest option. When mounting local files into a container then I’ve made good experiences with cached:

The macOS host’s view of the mount is authoritative. There may be delays before updates made on the host are visible within a container.