Rails サーバーの立ち上げがうまくいかない 動作確認できない

Question

動作確認をしたく、サーバーを立ち上げたいのですがうまくいきません。

どのよう手順が必要なのでしょうか。

やってみたこととしては、docker-compose.yml内の編集です。

api_1  | Mysql2::Error::ConnectionError (Unknown MySQL server host 'db' (-2)):
api_1  |   
api_1  | mysql2 (0.5.3) lib/mysql2/client.rb:90:in `connect'
api_1  | mysql2 (0.5.3) lib/mysql2/client.rb:90:in `initialize'
api_1  | activerecord (6.0.3.1) lib/active_record/connection_adapters/mysql2_adapter.rb:24:in `new'
api_1  | activerecord (6.0.3.1) lib/active_record/connection_adapters/mysql2_adapter.rb:24:in `mysql2_connection'
api_1  | activerecord (6.0.3.1) lib/active_record/connection_adapters/abstract/connection_pool.rb:887:in `new_connection'
api_1  | activerecord (6.0.3.1) lib/active_record/connection_adapters/abstract/connection_pool.rb:931:in `checkout_new_connection'
api_1  | activerecord (6.0.3.1) lib/active_record/connection_adapters/abstract/connection_pool.rb:910:in `try_to_checkout_new_connection'
api_1  | activerecord (6.0.3.1) lib/active_record/connection_adapters/abstract/connection_pool.rb:871:in `acquire_connection'
api_1  | activerecord (6.0.3.1) lib/active_record/connection_adapters/abstract/connection_pool.rb:593:in `checkout'
api_1  | activerecord (6.0.3.1) lib/active_record/connection_adapters/abstract/connection_pool.rb:437:in `connection'
api_1  | activerecord (6.0.3.1) lib/active_record/connection_adapters/abstract/connection_pool.rb:1119:in `retrieve_connection'
api_1  | activerecord (6.0.3.1) lib/active_record/connection_handling.rb:221:in `retrieve_connection'
api_1  | activerecord (6.0.3.1) lib/active_record/connection_handling.rb:189:in `connection'
api_1  | activerecord (6.0.3.1) lib/active_record/migration.rb:562:in `call'
api_1  | actionpack (6.0.3.1) lib/action_dispatch/middleware/callbacks.rb:27:in `block in call'
api_1  | activesupport (6.0.3.1) lib/active_support/callbacks.rb:101:in `run_callbacks'
api_1  | actionpack (6.0.3.1) lib/action_dispatch/middleware/callbacks.rb:26:in `call'
api_1  | actionpack (6.0.3.1) lib/action_dispatch/middleware/executor.rb:14:in `call'
api_1  | actionpack (6.0.3.1) lib/action_dispatch/middleware/actionable_exceptions.rb:17:in `call'
api_1  | actionpack (6.0.3.1) lib/action_dispatch/middleware/debug_exceptions.rb:32:in `call'
api_1  | actionpack (6.0.3.1) lib/action_dispatch/middleware/show_exceptions.rb:33:in `call'
api_1  | railties (6.0.3.1) lib/rails/rack/logger.rb:37:in `call_app'
api_1  | railties (6.0.3.1) lib/rails/rack/logger.rb:26:in `block in call'
api_1  | activesupport (6.0.3.1) lib/active_support/tagged_logging.rb:80:in `block in tagged'
api_1  | activesupport (6.0.3.1) lib/active_support/tagged_logging.rb:28:in `tagged'
api_1  | activesupport (6.0.3.1) lib/active_support/tagged_logging.rb:80:in `tagged'
api_1  | railties (6.0.3.1) lib/rails/rack/logger.rb:26:in `call'
api_1  | actionpack (6.0.3.1) lib/action_dispatch/middleware/remote_ip.rb:81:in `call'
api_1  | actionpack (6.0.3.1) lib/action_dispatch/middleware/request_id.rb:27:in `call'
api_1  | rack (2.2.2) lib/rack/runtime.rb:22:in `call'
api_1  | activesupport (6.0.3.1) lib/active_support/cache/strategy/local_cache_middleware.rb:29:in `call'
api_1  | actionpack (6.0.3.1) lib/action_dispatch/middleware/executor.rb:14:in `call'
api_1  | actionpack (6.0.3.1) lib/action_dispatch/middleware/static.rb:126:in `call'
api_1  | rack (2.2.2) lib/rack/sendfile.rb:110:in `call'
api_1  | actionpack (6.0.3.1) lib/action_dispatch/middleware/host_authorization.rb:82:in `call'
api_1  | railties (6.0.3.1) lib/rails/engine.rb:527:in `call'
api_1  | puma (4.3.5) lib/puma/configuration.rb:228:in `call'
api_1  | puma (4.3.5) lib/puma/server.rb:713:in `handle_request'
api_1  | puma (4.3.5) lib/puma/server.rb:472:in `process_client'
api_1  | puma (4.3.5) lib/puma/server.rb:328:in `block in run'
api_1  | puma (4.3.5) lib/puma/thread_pool.rb:134:in `block in spawn_thread'

version: '3'
services:
  app:
    build: ./app
    tty: true
    volumes:
      - ./app:/app
      - app_node_modules:/app/node_modules
    ports:
      - '4000:4000'

  db:
    image: mysql:5.7
    environment:
      MYSQL_DATABASE: root
      MYSQL_ROOT_PASSWORD: password
    ports:
      - '3306:3306'
    volumes:
      - db_data:/var/lib/mysql

  api:
    build: ./api
    command: bundle exec rails s -p 3000 -b '0.0.0.0'
    volumes:
      - ./api:/api
    ports:
      - '3000:3000'
    links:
      - db

volumes:
  app_node_modules:
  db_data:

# MySQL. Versions 5.5.8 and up are supported.
#
# Install the MySQL driver
#   gem install mysql2
#
# Ensure the MySQL gem is defined in your Gemfile
#   gem 'mysql2'
#
# And be sure to use new-style password hashing:
#   https://dev.mysql.com/doc/refman/5.7/en/password-hashing.html
#
default: &default
  adapter: mysql2
  encoding: utf8mb4
  pool: <%= ENV.fetch("RAILS_MAX_THREADS") { 5 } %>
  username: <%= ENV.fetch("MYSQL_DATABASE") { "root" } %>
  password: <%= ENV.fetch("MYSQL_ROOT_PASSWORD") { "password" } %>
  host: db

development:
  <<: *default
  database: home_care_navi_development

# Warning: The database defined as "test" will be erased and
# re-generated from your development database when you run "rake".
# Do not set this db to the same as development or production.
test:
  <<: *default
  database: home_care_navi_test

# As with config/credentials.yml, you never want to store sensitive information,
# like your database password, in your source code. If your source code is
# ever seen by anyone, they now have access to your database.
#
# Instead, provide the password as a unix environment variable when you boot
# the app. Read https://guides.rubyonrails.org/configuring.html#configuring-a-database
# for a full rundown on how to provide these environment variables in a
# production deployment.
#
# On Heroku and other platform providers, you may have a full connection URL
# available as an environment variable. For example:
#
#   DATABASE_URL="mysql2://myuser:mypass@localhost/somedatabase"
#
# You can use this database configuration with:
#
#   production:
#     url: <%= ENV['DATABASE_URL'] %>
#
production:
  <<: *default
  database: home_care_navi_production
  username: home_care_navi
  password: <%= ENV['home_care_navi_DATABASE_PASSWORD'] %>

Comments

[m.ts10806]

SQL Serverは本件とどのように関係するのでしょう。
画像からするとMySQLのようですが・・

ただ、画像だと画面キャプチャだとしても限界があるのでエラーメッセージならコピーしてそのままテキストで提示された方が良いかと思います。

[masaosan18]

ありがとうございます！

[m.ts10806]

>Unknown MySQL server host 'db'

アプリケーション側の接続設定ファイルの内容提示してもらった方が良いかもしれませんが、
ホスト名「db」は本当ですか？
通常はサーバーのIPとかアプリケーションとDBが同じサーバ内ならlocalhostとかが入るものと思いますが。

[masaosan18]

これであっていますでしょうか・・・

[winterboum]

config/database.yml がおかしいかも

[m.ts10806]

通常はサーバーのIPとかアプリケーションとDBが同じサーバ内ならlocalhostとかが入るものと思いますが。

[masaosan18]

そういえば、調べててMySQLがクラッシュしたみたいな記事にたどり着きまして、おとといあたりにPCが動かなくなり、強制終了しました。

[m.ts10806]

あの。今自身が目の前で起きている現象とエラーメッセージに目を向けてください。
>Unknown MySQL server host 'db'

これ、そのままですよ。

[CHERRY]

> docker-compose.yml

docker でコンテナは正しく稼働していますか？

[YakumoSaki]

docker-compose up した状態で、docker ps を実行して、コンテナが３つ立ち上がっているのか確認すると良いかもしれません。 DBのコンテナが何らかの理由で起動していなければこのエラーメッセージがでると思います。

Answer 1

docker system prune --volumes

これで解決しました。