【发布时间】：2020-02-25 08:02:59
【问题描述】：
我有 Rails 应用程序 ubuntu 18.04。 bundle install 运行成功，但是当我运行 rake db:setup 时它显示
rake 中止！
KeyError：找不到密钥：“URL_HOST”
/var/www/myapp/code/config/environments/production.rb:71:in fetch'
/var/www/myapp/code/config/environments/production.rb:71:inblock in '
/home/myappuser/.rvm/gems/ruby-2.5.0/gems/railties-4.2.11.1/lib/rails/railtie.rb:210:in instance_eval'
/home/myappuser/.rvm/gems/ruby-2.5.0/gems/railties-4.2.11.1/lib/rails/railtie.rb:210:inconfigure'
/var/www/myapp/code/config/environments/production.rb:3:in <top (required)>'
/home/myappuser/.rvm/gems/ruby-2.5.0/gems/activesupport-4.2.11.1/lib/active_support/dependencies.rb:274:inrequire'
/home/myappuser/.rvm/gems/ruby-2.5.0/gems/activesupport-4.2.11.1/lib/active_support/dependencies.rb:274:in block in require'
/home/myappuser/.rvm/gems/ruby-2.5.0/gems/activesupport-4.2.11.1/lib/active_support/dependencies.rb:240:inload_dependency'
/home/myappuser/.rvm/gems/ruby-2.5.0/gems/activesupport-4.2.11.1/lib/active_support/dependencies.rb:274:in require'
/home/myappuser/.rvm/gems/ruby-2.5.0/gems/railties-4.2.11.1/lib/rails/engine.rb:598:inblock (2 级) in '
/home/myappuser/.rvm/gems/ruby-2.5.0/gems/railties-4.2.11.1/lib/rails/engine.rb:597:in each'
/home/myappuser/.rvm/gems/ruby-2.5.0/gems/railties-4.2.11.1/lib/rails/engine.rb:597:inblock in '
/home/myappuser/.rvm/gems/ruby-2.5.0/gems/railties-4.2.11.1/lib/rails/initializable.rb:30:in instance_exec'
/home/myappuser/.rvm/gems/ruby-2.5.0/gems/railties-4.2.11.1/lib/rails/initializable.rb:30:inrun'
/home/myappuser/.rvm/gems/ruby-2.5.0/gems/railties-4.2.11.1/lib/rails/initializable.rb:55:in block in run_initializers'
/home/myappuser/.rvm/gems/ruby-2.5.0/gems/railties-4.2.11.1/lib/rails/initializable.rb:44:ineach'
/home/myappuser/.rvm/gems/ruby-2.5.0/gems/railties-4.2.11.1/lib/rails/initializable.rb:44:in tsort_each_child'
/home/myappuser/.rvm/gems/ruby-2.5.0/gems/railties-4.2.11.1/lib/rails/initializable.rb:54:inrun_initializers'
/home/myappuser/.rvm/gems/ruby-2.5.0/gems/railties-4.2.11.1/lib/rails/application.rb:352:in initialize!'
/var/www/myapp/code/config/environment.rb:5:in'
/home/myappuser/.rvm/gems/ruby-2.5.0/gems/activesupport-4.2.11.1/lib/active_support/dependencies.rb:274:in require'
/home/myappuser/.rvm/gems/ruby-2.5.0/gems/activesupport-4.2.11.1/lib/active_support/dependencies.rb:274:inblock in require'
/home/myappuser/.rvm/gems/ruby-2.5.0/gems/activesupport-4.2.11.1/lib/active_support/dependencies.rb:240:in load_dependency'
/home/myappuser/.rvm/gems/ruby-2.5.0/gems/activesupport-4.2.11.1/lib/active_support/dependencies.rb:274:inrequire'
/home/myappuser/.rvm/gems/ruby-2.5.0/gems/railties-4.2.11.1/lib/rails/application.rb:328:in require_environment!'
/home/myappuser/.rvm/gems/ruby-2.5.0/gems/railties-4.2.11.1/lib/rails/application.rb:457:inblock in run_tasks_blocks'
/home/myappuser/.rvm/gems/ruby-2.5.0/gems/rake-13.0.0/exe/rake:27:in <top (required)>'
/home/myappuser/.rvm/gems/ruby-2.5.0/bin/ruby_executable_hooks:24:ineval'
/home/myappuser/.rvm/gems/ruby-2.5.0/bin/ruby_executable_hooks:24:in `'
任务：TOP => db:setup => db:schema:load_if_ruby => 环境
（通过使用 --trace 运行任务查看完整跟踪）
需要帮助
【问题讨论】：
-
我们可以看看你的 /var/www/myapp/code/config/environments/production.rb:71 的内容吗？从它出现的情况来看，您可能需要提供
URL_HOST环境变量
标签： ruby-on-rails ruby ruby-on-rails-3 rubygems ruby-on-rails-5