尝试在生产环境中启动 Rails 服务器答案

【问题标题】：Trying to start rails server in production environment尝试在生产环境中启动 Rails 服务器
【发布时间】：2018-10-23 17:17:15
【问题描述】：

Rails 服务器没有在生产环境中启动，我认为与数据库存在冲突，我应该迁移它们还是其他？

=> Booting Puma
=> Rails 5.0.6 application starting in production on http://0.0.0.0:3000
=> Run `rails server -h` for more startup options
Exiting
/home/user/.rbenv/versions/2.3.3/lib/ruby/gems/2.3.0/gems/activerecord-5.0.6/lib/active_record/connection_adapters/connection_specification.rb:170:in
`spec': database configuration does not specify adapter
(ActiveRecord::AdapterNotSpecified)
    from /home/user/.rbenv/versions/2.3.3/lib/ruby/gems/2.3.0/gems/activerecord-5.0.6/lib/active_record/connection_handling.rb:53:in `establish_connection'
    from /home/user/.rbenv/versions/2.3.3/lib/ruby/gems/2.3.0/gems/activerecord-5.0.6/lib/active_record/railtie.rb:125:in `block (2 levels) in <class:Railtie>'
    from /home/user/.rbenv/versions/2.3.3/lib/ruby/gems/2.3.0/gems/activesupport-5.0.6/lib/active_support/lazy_load_hooks.rb:69:in `instance_eval'
    from /home/user/.rbenv/versions/2.3.3/lib/ruby/gems/2.3.0/gems/activesupport-5.0.6/lib/active_support/lazy_load_hooks.rb:69:in `block in execute_hook'
    from /home/user/.rbenv/versions/2.3.3/lib/ruby/gems/2.3.0/gems/activesupport-5.0.6/lib/active_support/lazy_load_hooks.rb:60:in `with_execution_control'
    from /home/user/.rbenv/versions/2.3.3/lib/ruby/gems/2.3.0/gems/activesupport-5.0.6/lib/active_support/lazy_load_hooks.rb:65:in `execute_hook'
    from /home/user/.rbenv/versions/2.3.3/lib/ruby/gems/2.3.0/gems/activesupport-5.0.6/lib/active_support/lazy_load_hooks.rb:41:in `block in on_load'
    from /home/user/.rbenv/versions/2.3.3/lib/ruby/gems/2.3.0/gems/activesupport-5.0.6/lib/active_support/lazy_load_hooks.rb:40:in `each'
    from /home/user/.rbenv/versions/2.3.3/lib/ruby/gems/2.3.0/gems/activesupport-5.0.6/lib/active_support/lazy_load_hooks.rb:40:in `on_load'
    from /home/user/.rbenv/versions/2.3.3/lib/ruby/gems/2.3.0/gems/activerecord-5.0.6/lib/active_record/railtie.rb:121:in `block in <class:Railtie>'
    from /home/user/.rbenv/versions/2.3.3/lib/ruby/gems/2.3.0/gems/railties-5.0.6/lib/rails/initializable.rb:30:in `instance_exec'
    from /home/user/.rbenv/versions/2.3.3/lib/ruby/gems/2.3.0/gems/railties-5.0.6/lib/rails/initializable.rb:30:in `run'
    from /home/user/.rbenv/versions/2.3.3/lib/ruby/gems/2.3.0/gems/railties-5.0.6/lib/rails/initializable.rb:55:in `block in run_initializers'
    from /home/user/.rbenv/versions/2.3.3/lib/ruby/2.3.0/tsort.rb:228:in `block in tsort_each'
    from /home/user/.rbenv/versions/2.3.3/lib/ruby/2.3.0/tsort.rb:350:in `block (2 levels) in each_strongly_connected_component'
    from /home/user/.rbenv/versions/2.3.3/lib/ruby/2.3.0/tsort.rb:431:in `each_strongly_connected_component_from'
    from /home/user/.rbenv/versions/2.3.3/lib/ruby/2.3.0/tsort.rb:349:in `block in each_strongly_connected_component'
    from /home/user/.rbenv/versions/2.3.3/lib/ruby/2.3.0/tsort.rb:347:in `each'
    from /home/user/.rbenv/versions/2.3.3/lib/ruby/2.3.0/tsort.rb:347:in `call'
    from /home/user/.rbenv/versions/2.3.3/lib/ruby/2.3.0/tsort.rb:347:in `each_strongly_connected_component'
    from /home/user/.rbenv/versions/2.3.3/lib/ruby/2.3.0/tsort.rb:226:in `tsort_each'
    from /home/user/.rbenv/versions/2.3.3/lib/ruby/2.3.0/tsort.rb:205:in `tsort_each'
    from /home/user/.rbenv/versions/2.3.3/lib/ruby/gems/2.3.0/gems/railties-5.0.6/lib/rails/initializable.rb:54:in `run_initializers'
    from /home/user/.rbenv/versions/2.3.3/lib/ruby/gems/2.3.0/gems/railties-5.0.6/lib/rails/application.rb:352:in `initialize!'
    from /home/user/Desktop/upgraded-carnival/config/environment.rb:5:in `<top (required)>'
    from /home/user/Desktop/upgraded-carnival/config.ru:3:in `require_relative'
    from /home/user/Desktop/upgraded-carnival/config.ru:3:in `block in <main>'
    from /home/user/.rbenv/versions/2.3.3/lib/ruby/gems/2.3.0/gems/rack-2.0.3/lib/rack/builder.rb:55:in `instance_eval'
    from /home/user/.rbenv/versions/2.3.3/lib/ruby/gems/2.3.0/gems/rack-2.0.3/lib/rack/builder.rb:55:in `initialize'
    from /home/user/Desktop/upgraded-carnival/config.ru:in `new'
    from /home/user/Desktop/upgraded-carnival/config.ru:in `<main>'
    from /home/user/.rbenv/versions/2.3.3/lib/ruby/gems/2.3.0/gems/rack-2.0.3/lib/rack/builder.rb:49:in `eval'
    from /home/user/.rbenv/versions/2.3.3/lib/ruby/gems/2.3.0/gems/rack-2.0.3/lib/rack/builder.rb:49:in `new_from_string'
    from /home/user/.rbenv/versions/2.3.3/lib/ruby/gems/2.3.0/gems/rack-2.0.3/lib/rack/builder.rb:40:in `parse_file'
    from /home/user/.rbenv/versions/2.3.3/lib/ruby/gems/2.3.0/gems/rack-2.0.3/lib/rack/server.rb:319:in `build_app_and_options_from_config'
    from /home/user/.rbenv/versions/2.3.3/lib/ruby/gems/2.3.0/gems/rack-2.0.3/lib/rack/server.rb:219:in `app'
    from /home/user/.rbenv/versions/2.3.3/lib/ruby/gems/2.3.0/gems/railties-5.0.6/lib/rails/commands/server.rb:84:in `app'
    from /home/user/.rbenv/versions/2.3.3/lib/ruby/gems/2.3.0/gems/rack-2.0.3/lib/rack/server.rb:354:in `wrapped_app'
    from /home/user/.rbenv/versions/2.3.3/lib/ruby/gems/2.3.0/gems/rack-2.0.3/lib/rack/server.rb:283:in `start'
    from /home/user/.rbenv/versions/2.3.3/lib/ruby/gems/2.3.0/gems/railties-5.0.6/lib/rails/commands/server.rb:104:in `start'
    from /home/user/.rbenv/versions/2.3.3/lib/ruby/gems/2.3.0/gems/railties-5.0.6/lib/rails/commands/commands_tasks.rb:90:in `block in server'
    from /home/user/.rbenv/versions/2.3.3/lib/ruby/gems/2.3.0/gems/railties-5.0.6/lib/rails/commands/commands_tasks.rb:85:in `tap'
    from /home/user/.rbenv/versions/2.3.3/lib/ruby/gems/2.3.0/gems/railties-5.0.6/lib/rails/commands/commands_tasks.rb:85:in `server'
    from /home/user/.rbenv/versions/2.3.3/lib/ruby/gems/2.3.0/gems/railties-5.0.6/lib/rails/commands/commands_tasks.rb:49:in `run_command!'
    from /home/user/.rbenv/versions/2.3.3/lib/ruby/gems/2.3.0/gems/railties-5.0.6/lib/rails/commands.rb:18:in `<top (required)>'
    from bin/rails:4:in `require'
    from bin/rails:4:in `<main>'

我的数据库.yml：

default: &default   
  adapter: postgresql   
  encoding: unicode
  pool: <%= ENV.fetch("RAILS_MAX_THREADS") { 5 } %>

production:
  host: localhost
  database: magnetcoin_production  
  pool:     10   
  timeout:  10000   
  username: magnetcoin   
  password:
  magnetcoin   template: template0

development:   <<: *default   
  database: magnetcoin_development

test:   <<: *default   
  database: magnetcoin_test

【问题讨论】：

在开发环境中一切正常
请分享您的database.yml 文件。
默认值：&default 适配器：postgresql 编码：unicode 池：生产：主机：localhost 数据库：magnetcoin_production 池：10 超时：10000 用户名：magnetcoin 密码：magnetcoin 模板：template0 开发：
使用正确的格式将 database.yml 文件添加到您的原始问题中，否则无法帮助您。
更新>>>>>>>>

标签： ruby-on-rails ruby activerecord ruby-on-rails-5

【解决方案1】：

根据您的日志，您没有为生产环境数据库配置定义适配器。您在默认块中添加了适配器，但没有将默认值导入生产块。只需在生产块中导入默认块，一切正常。

default: &default 
  adapter: postgresql 
  encoding: unicode 
  pool: <%= ENV.fetch("RAILS_MAX_THREADS") { 5 } %> 

production: <<: *default
  host: localhost 
  database: magnetcoin_production 
  pool: 10 
  timeout: 10000 
  username: magnetcoin 
  password: magnetcoin 
  template: template0 

development: <<: *default 
  database: magnetcoin_development 

test: <<: *default 
  database: magnetcoin_test

【讨论】：