/home/web/.gem/ruby/2.2.0/gems/redis-3.2.1/lib/redis/connection/ruby.rb:152:in`getaddrinfo'：getaddrinfo：名稱或服務未知（SocketError）

Question

我正在使用docker-compose為開發人員提供技術堆棧ROR，postgres，redis，mongo的開發環境。 docker-compose build成功運行但是當我運行docker-compose up遇到docker-compose up以下錯誤。

web_1   | => Booting Thin
web_1   | => Rails 4.2.3 application starting in development on http://0.0.0.0:3000
web_1   | => Run `rails server -h` for more startup options
web_1   | => Ctrl-C to shutdown server
web_1   | Exiting
web_1   | /home/web/.gem/ruby/2.2.0/gems/redis-3.2.1/lib/redis/connection/ruby.rb:152:in `getaddrinfo': getaddrinfo: Name or service not known (SocketError)
web_1   |   from /home/web/.gem/ruby/2.2.0/gems/redis-3.2.1/lib/redis/connection/ruby.rb:152:in `connect'
web_1   |   from /home/web/.gem/ruby/2.2.0/gems/redis-3.2.1/lib/redis/connection/ruby.rb:211:in `connect'
web_1   |   from /home/web/.gem/ruby/2.2.0/gems/redis-3.2.1/lib/redis/client.rb:322:in `establish_connection'
web_1   |   from /home/web/.gem/ruby/2.2.0/gems/redis-3.2.1/lib/redis/client.rb:94:in `block in connect'
web_1   |   from /home/web/.gem/ruby/2.2.0/gems/redis-3.2.1/lib/redis/client.rb:279:in `with_reconnect'

以下是Dockerfile

# Base image.
FROM atlashealth/ruby:2.2.1

# System dependencies for gems.
#RUN apt-get update
#RUN apt-get install -y --no-install-recommends libmysqlclient-dev
RUN apt-get update -qq && apt-get install -y build-essential libpq-dev 

# Add 'web' user which will run the application.
RUN adduser web --home /home/web --shell /bin/bash --disabled-password --gecos ""

# Add directory where all application code will live and own it by the web user.
RUN mkdir /app
RUN chown -R web:web /app

# Install gems separately here to take advantage of container caching of `bundle install`.
# Also, ensure that gems are installed as the web user and not system-wide so that we can run
# `fig web bundle install` and the web user will have permissions to update the shared Gemfile.lock.
ADD Gemfile /app/
ADD Gemfile.lock /app/
RUN chown -R web:web /app
USER web
ENV HOME /home/web
ENV PATH $PATH:/home/web/.gem/ruby/2.2.0/bin
ENV GEM_HOME /home/web/.gem/ruby/2.2.0
ENV GEM_PATH $GEM_HOME
RUN gem install --user-install bundler
WORKDIR /app/
RUN bundle install
USER root

# Add the whole application source to the image and own it all by web:web.
# Note: this is overwritten in development because fig mounts a shared volume at /app.
ADD . /app/
RUN chown -R web:web /app

# Clean up APT and /tmp when done.
RUN apt-get clean && rm -rf /var/lib/apt/lists/* /tmp/* /var/tmp/*

# Default command to run when this container is run.
USER web
WORKDIR /app/
CMD ["bundle", "exec", "rails", "server"]

泊塢窗，compose.yml

db:  
  image: postgres
  ports:
    - "5432"

redis:  
  image: redis
  ports:
    - "6379"

sidekiq:  
  build: .
  command: bundle exec sidekiq
  links:
    - db
    - redis

web:  
  build: .
  command: bundle exec rails s -b 0.0.0.0
  volumes:
    - .:/app
  ports:
    - "3000:3000"
  links:
    - db
    - redis

我根據docker-compose run web env命令的輸出為postgres和redis主機和端口設置了環境變量。

命令docker-compose run web cat /etc/hosts輸出docker-compose run web cat /etc/hosts

Starting xyz_db_1...
Starting xyz_redis_1...
172.17.0.32 2b231a706e7b
127.0.0.1   localhost
::1 localhost ip6-localhost ip6-loopback
fe00::0 ip6-localnet
ff00::0 ip6-mcastprefix
ff02::1 ip6-allnodes
ff02::2 ip6-allrouters
172.17.0.31 redis 799b65ac89cd xyz_redis_1
172.17.0.31 redis_1 799b65ac89cd xyz_redis_1
172.17.0.30 db 0bd898e19822 xyz_db_1
172.17.0.30 db_1 0bd898e19822 xyz_db_1
172.17.0.30 xyz_db_1 0bd898e19822
172.17.0.31 xyz_redis_1 799b65ac89cd

配置/ sidekiq.yml

concurrency: 25
pidfile: ./tmp/pids/sidekiq.pid
logfile: ./log/sidekiq.log
queues:
  - default
  - [priority, 2]
daemon: true

配置/ APP-config.yml

default: &default
  redis_host: <%= ENV['XYZ_REDIS_1_PORT_6379_TCP_ADDR'] %>
  redis_port: <%= ENV ['XYZ_REDIS_1_PORT_6379_TCP_PORT'] %>
  redis_namespace: 'RAILS_CACHE'

development:
  <<: *default
  redis_host: <%= ENV['XYZ_REDIS_1_PORT_6379_TCP_ADDR'] %>
  redis_port: <%= ENV['XYZ_REDIS_1_PORT_6379_TCP_PORT'] %>

配置/初始化/ redis.rb

# global variable to access Redis cache
# Requirement: Redis server should be up and running
# at below specified host and port
$redis = Redis.new(
  :host => APP_CONFIG["redis_host"],
  :port => APP_CONFIG["redis_port"]
)

Answer 1

REDIS_URL環境變量可用於將Redis URL傳遞給Sidekiq和Redis gem。

可以在docker-compose.yml設置此環境變量，如下所示：

db:  
  image: postgres
  ports:
    - "5432"

redis:  
  image: redis
  ports:
    - "6379"

web:  
  build: .
  command: bundle exec rails s -b 0.0.0.0
  volumes:
    - .:/app
  ports:
    - "3000:3000"
  links:
    - db
    - redis
  environment:
    REDIS_URL: "redis://redis:6379"

由於Sidekiq和Redis的寶石默認使用REDIS_URL ，因此您還需要確保在配置文件中沒有覆蓋此默認行為。 你不再需要文件config/initializers/redis.rb了，你的config/app-config.yml應該只包含你的命名空間：

default: &default
  redis_namespace: 'RAILS_CACHE'

development:
  <<: *default