Rake 任务将database.example.yml 复制到database.yml

Question

通过rake任务将database.example.yml复制到database.yml时出现错误

copy_files.rake

namespace :copy do
  desc "copy database.yml & application.yml"
  task :config_files => :environment do
    source = File.join(Rails.root, "config", "database.example.yml")
    target = File.join(Rails.root, "config", "database.yml")
    FileUtils.cp_r source, target
  end
end

错误

$ rake copy:config_files
rake aborted!
Cannot load `Rails.application.database_configuration`:
Could not load database configuration. No such file - 
/Library/Ruby/Gems/2.0.0/gems/railties-4.1.4/lib/rails/application/configuration.rb:105:in `database_configuration'
/Library/Ruby/Gems/2.0.0/gems/activerecord-4.1.4/lib/active_record/railtie.rb:128:in `block (2 levels) in <class:Railtie>'
/Library/Ruby/Gems/2.0.0/gems/activesupport-4.1.4/lib/active_support/lazy_load_hooks.rb:38:in `instance_eval'
/Library/Ruby/Gems/2.0.0/gems/activesupport-4.1.4/lib/active_support/lazy_load_hooks.rb:38:in `execute_hook'
/Library/Ruby/Gems/2.0.0/gems/activesupport-4.1.4/lib/active_support/lazy_load_hooks.rb:28:in `block in on_load'
/Library/Ruby/Gems/2.0.0/gems/activesupport-4.1.4/lib/active_support/lazy_load_hooks.rb:27:in `each'
/Library/Ruby/Gems/2.0.0/gems/activesupport-4.1.4/lib/active_support/lazy_load_hooks.rb:27:in `on_load'
/Library/Ruby/Gems/2.0.0/gems/activerecord-4.1.4/lib/active_record/railtie.rb:118:in `block in <class:Railtie>'
/Library/Ruby/Gems/2.0.0/gems/railties-4.1.4/lib/rails/initializable.rb:30:in `instance_exec'
/Library/Ruby/Gems/2.0.0/gems/railties-4.1.4/lib/rails/initializable.rb:30:in `run'
/Library/Ruby/Gems/2.0.0/gems/railties-4.1.4/lib/rails/initializable.rb:55:in `block in run_initializers'
/Library/Ruby/Gems/2.0.0/gems/railties-4.1.4/lib/rails/initializable.rb:54:in `run_initializers'
/Library/Ruby/Gems/2.0.0/gems/railties-4.1.4/lib/rails/application.rb:300:in `initialize!'
/Library/Ruby/Gems/2.0.0/gems/railties-4.1.4/lib/rails/railtie.rb:194:in `public_send'
/Library/Ruby/Gems/2.0.0/gems/railties-4.1.4/lib/rails/railtie.rb:194:in `method_missing'
/config/environment.rb:5:in `<top (required)>'
/Library/Ruby/Gems/2.0.0/gems/activesupport-4.1.4/lib/active_support/dependencies.rb:247:in `require'
/Library/Ruby/Gems/2.0.0/gems/activesupport-4.1.4/lib/active_support/dependencies.rb:247:in `block in require'
/Library/Ruby/Gems/2.0.0/gems/activesupport-4.1.4/lib/active_support/dependencies.rb:232:in `load_dependency'
/Library/Ruby/Gems/2.0.0/gems/activesupport-4.1.4/lib/active_support/dependencies.rb:247:in `require'
/Library/Ruby/Gems/2.0.0/gems/railties-4.1.4/lib/rails/application.rb:276:in `require_environment!'
/Library/Ruby/Gems/2.0.0/gems/railties-4.1.4/lib/rails/application.rb:379:in `block in run_tasks_blocks'
Tasks: TOP => copy:config_files => environment
(See full trace by running task with --trace)

我看到错误是因为没有database.yml文件。有没有可能通过 rake 任务复制database.yml 文件的方法？

Answer 1

我很惊讶！但@SrikanthJeeva 是对的:)

我成功地在没有

database.yml

的情况下运行了 rake 任务。您应该删除

:environment

并且不能使用

Rails.root

（因为没有database.yml 就无法加载Rails）。这对我有用

  desc "copy database.yml & application.yml"
  task :config_files do
    source = File.join(Dir.pwd, "config", "database.example.yml")
    target = File.join(Dir.pwd, "config", "database.yml")
    FileUtils.cp_r source, target
  end

Answer 2

您需要一个“有效”环境来使用

=> :environment

运行 rake 任务。这样，rake 任务就会加载 Rails 环境，并且需要存在

database.yaml

文件。

例如，您可以在 IRB 会话中使用 Ruby 本身来实现此目的：

$ cd /app_rails_root_path
$ irb
> Dir.glob("config/*.yml.example").each { |f| FileUtils.cp(f, f.gsub(/\.example/, '')) }