更新docker容器的Ruby bin文件夹的正确方法是什么？

Question

I've been play around with converting an existing Ruby on Rails application to be developed in a docker container. I don't understand where best to incorporate the rake rails:update:bin command. I tried to put it as the last line of the dockerfile but the container won't start up properly. The only way I can get the container to start up is to build the bin outside of the image construction, so that the bin folder is pulled in with an ADD command.

Is it possible to create a dockerfile that does all the things?

---

The Docker file looks like this

FROM ruby:2.2
RUN apt-get update && apt-get install -y \
    build-essential \
    libpq-dev \
    nodejs
RUN mkdir /MyApp
WORKDIR /MyApp
ADD Gemfile /MyApp/Gemfile
ADD Gemfile.lock /MyApp/Gemfile.lock
RUN bundle install
ADD . /MyApp

I want to add the following line to the end.

RUN rake rails:update:bin

When I try including the rake command I'm rebuilding the image without the bin folder in the MyApp folder. When I leave the rake command off I'm rebuilding the image with the bin folder. And I know I'm truly rebuilding the images because I delete the cached versions before I rebuild them.

Answer 1

I finally figured out a resolution here. I added the rake rails:update:bin call to the command just before the server starts.

I created the following shell script to set as the docker-compose.yml command

#!/bin/bash

rake rails:update:bin

# start the SSH server for connecting the debugger in development
/usr/sbin/sshd -D &
bundle exec rails s -p 3000 -b '0.0.0.0'

My docker-compose.yml looks like this

version: '2'
services:
  web:
    build: .
    command: /MyApp/docker-dev-start.sh
    volumes:
      - .:/MyApp
    ports:
      - "3000:3000"
      - "3022:22"

and my dockerfile ended up looking like this

FROM ruby:2.2
RUN apt-get update && apt-get install -y \
    build-essential \
    libpq-dev \
    nodejs \
    openssh-server

RUN mkdir /var/run/sshd
RUN echo 'root:screencast' | chpasswd
RUN sed -i 's/PermitRootLogin .*/PermitRootLogin yes/' /etc/ssh/sshd_config

# SSH login fix. Otherwise user is kicked off after login
RUN sed 's@session\s*required\s*pam_loginuid.so@session optional pam_loginuid.so@g' -i /etc/pam.d/sshd

ENV NOTVISIBLE "in users profile"
RUN echo "export VISIBLE=now" >> /etc/profile

RUN mkdir /MyApp
WORKDIR /MyApp
ADD Gemfile /MyApp/Gemfile
ADD Gemfile.lock /MyApp/Gemfile.lock
RUN bundle install
ADD . /MyApp

The SSH server is included to be able to connect an external IDE for debugging.