Question

我们可以使用单个源和单个multiple development instances文件连接到database.yml吗？我的意思是，我需要有来自同一来源的4个开发实例，它连接4个不同的MySQL数据库。我可以使用不同的PORT ID s启动服务器吗？

示例：

development:
  adapter: mysql2
  database: TEST1_development
  host: localhost
  username: root
  password: password
  encoding: utf8
  pool: 30

development-2:
  adapter: mysql2
  database: TEST2_development
  host: localhost
  username: root
  password: password
  encoding: utf8
  pool: 30

development-3:
  adapter: mysql2
  database: TEST3_development
  host: localhost
  username: root
  password: password
  encoding: utf8
  pool: 30

development-4:
  adapter: mysql2
  database: TEST4_development
  host: localhost
  username: root
  password: password
  encoding: utf8
  pool: 30

然后，我们如何启动4个不同的服务器（在localhost）同时连接这4个数据库？（我们通常在开发中使用rails server作为单个实例。）

谢谢:) -

Answer 1

您不仅限于默认的rails环境。您可以拥有development-2，development-3个环境。阅读this post on the 37signals blog where DHH talks about that

database.yml可以读取环境变量。

development:
  adapter: postgresql
  host: localhost
  database: <%= ENV['POSTGRES_DATABASE'] %>
  username: <%= ENV['POSTGRES_USER'] %>
  password: <%= ENV['POSTGRES_PASSWORD'] %>

然后确保在启动服务器时设置了这些内容。

Answer 2

这非常容易。

只需更新问题中提供的database.yml文件即可。假设我们的开发实例是development，development-2，development-3和development-4。

首先，您只需创建3个环境文件development.rb（可在config/environments/内找到）并将其重命名为development-2.rb，development-3.rb和development-4.rb。

然后，在启动服务器之前，请执行以下步骤。

RAILS_ENV=development rake db:create (OR just rake db:create as it defaults to development)
RAILS_ENV=development-2 rake db:create
RAILS_ENV=development-3 rake db:create
RAILS_ENV=development-4 rake db:create

RAILS_ENV=development rake db:schema:load (OR just rake db:schema:load as it defaults to development)
RAILS_ENV=development-2 rake db:schema:load
RAILS_ENV=development-3 rake db:schema:load
RAILS_ENV=development-4 rake db:schema:load

RAILS_ENV=development rake db:seed (OR just rake db:seed as it defaults to development)
RAILS_ENV=development-2 rake db:seed
RAILS_ENV=development-3 rake db:seed
RAILS_ENV=development-4 rake db:seed

然后，使用下面给出的不同服务器pid启动所有实例。

rails s -p 3000 -e development --pid tmp/pids/server.pid (OR rails s by default)
rails s -p 3002 -e development-2 --pid tmp/pids/server.2.pid
rails s -p 3003 -e development-3 --pid tmp/pids/server.3.pid
rails s -p 3004 -e development-4 --pid tmp/pids/server.4.pid

这将同时从同一个source和一个database.yml文件启动所有实例。感谢大家的所有回复和帮助:) -

Rails - 具有单个源和database.yml文件的多个开发实例

2 个答案: