主要内容：

1. Rails的Dockerfile创建：快速创建，避免漫长等待、只装有需要的包。
2. docker-compose.yml的配置：包括开发、生产环境
3. 问题记录：Yarn过期问题等

关于Dockerfile

使用的是ruby:2.5的基础镜像，相对来说干净
分下面几个部分：
1 基础docker镜像
2 更换源地址（国内用户必须更换，就算科学上网也不慢）
3 安装基础packages。
4 创建和设置工作目录，制作Gemfile，copy Gemfile，便于通过bundle安装rails。
5 创建enterpoint.sh ,这个里面内容重要，影响后续command里面的命令执行。

FROM ruby:2.5
LABEL maintainer="maweikeji"#武汉码为科技

# throw errors if Gemfile has been modified since Gemfile.lock
#RUN bundle config --global frozen 1
RUN bundle config mirror.https://rubygems.org https://gems.ruby-china.com

RUN curl -sS https://dl.yarnpkg.com/debian/pubkey.gpg | apt-key add -
RUN echo "deb http://dl.yarnpkg.com/debian/ stable main" | tee /etc/apt/sources.list.d/yarn.list

RUN  sed -i s@/archive.ubuntu.com/@/mirrors.aliyun.com/@g /etc/apt/sources.list
RUN  sed -i s@/deb.debian.org/@/mirrors.aliyun.com/@g /etc/apt/sources.list
RUN  sed -i s@/security.debian.org/@/mirrors.163.com/@g /etc/apt/sources.list
RUN  apt-get clean

RUN curl -sL https://deb.nodesource.com/setup_12.x | bash -
RUN apt-get update && apt-get install -y  nodejs  yarn mysql-client postgresql-client sqlite3 --no-install-recommends && rm -rf /var/lib/apt/lists/*

RUN mkdir -p /usr/src/app
WORKDIR /usr/src/app

COPY Gemfile /usr/src/app/Gemfile
COPY Gemfile.lock /usr/src/app/Gemfile.lock
RUN bundle install
#COPY api/. /usr/src/app （copy代码进去，或 在docker-compose.yml里面配置volumes）

# Add a script to be executed every time the container starts.
COPY entrypoint.sh /usr/bin/
RUN chmod +x /usr/bin/entrypoint.sh
ENTRYPOINT ["entrypoint.sh"]
EXPOSE 3000

# Start the main process.
CMD ["rails", "server", "-b", "0.0.0.0"]

entrypoint.sh文件

#enteypoint.sh
#!/bin/bash
set -e
# Remove a potentially pre-existing server.pid for Rails.
rm -f ./tmp/pids/server.pid
# Then exec the container's main process (what's set as CMD in the Dockerfile).
exec "$@"

docker-compose.yml

  app-owl_api:
    build:
      context: .
      dockerfile: ./api/Dockerfile-rails
    command: bin/dev.sh  # 生产环境下可以改成 bin/pro.sh
    volumes:
      - ./api:/usr/src/app
    ports:
      - "3001:3000"
    depends_on:
      - db
      - redis

几个麻烦点的问题

问题1：yarn的问题

Screenshot from 2019-05-27 18-48-44.png

yarn检查相关的js包里面的js语法出错！

app-owl_api_1    | yarn check v1.16.0
app-owl_api_1    | warning Integrity check: System parameters don't match
app-owl_api_1    | error Integrity check failed
app-owl_api_1    | error Found 1 errors.
app-owl_api_1    | info Visit https://yarnpkg.com/en/docs/cli/check for documentation about this command.

Installation Problem: Unexpected token { in cli.js

怎么解决？如果能找到那个包的版本有问题，那么就重装。重装会自动查找依赖，就是yarn的问题交给yarn去解决

yarn remove  xxx
yarn add xxx
#重新装各包

问题2：遇到一个Not agitrepository的问题

# [Receiving “fatal: Not a git repository” when attempting to remote add a Git repo](https://stackoverflow.com/questions/4630704/receiving-fatal-not-a-git-repository-when-attempting-to-remote-add-a-git-repo)

怎么处理：

git init .

问题3

Bundled gems are installed into `/usr/local/bundle`
Post-install message from i18n:

HEADS UP! i18n 1.1 changed fallbacks to exclude default locale.
But that may break your application.

Please check your Rails app for 'config.i18n.fallbacks = true'.
If you're using I18n (>= 1.1.0) and Rails (< 5.2.2), this should be
'config.i18n.fallbacks = [I18n.default_locale]'.
If not, fallbacks will be broken in your app by I18n 1.1.x.

For more info see:
https://github.com/svenfuchs/i18n/releases/tag/v1.1.0

参考，
https://www.firehydrant.io/blog/developing-a-ruby-on-rails-app-with-docker-compose/
https://docs.docker.com/compose/rails/
...