database.yml的Ruby和rails yaml解析器错误

Question

环境 Rails 3.2.14 Ruby 1.9.3p448 Ubuntu 12.04 bundler version 1.3.5

ruby​​ 1.9.3加载YAML的方式存在一些问题。如果我干掉databse.yml文件中的代码，rails console，server，generate etc命令就会失败。如果我删除这些默认值，那么一切正常。

我尝试了心理解析器和syck解析器。它只是错误跟踪在syck解析器中有所不同，但问题仍然存在。

以下只是示例。实际配置不同。 当database.yml是这样的时候会导致错误：

default: &default
  host: localhost
  ...

development:
  << *default
  pool: 5
  ...

当database.yml文件是这样的时候，完全正常工作：

development:
  host: localhost
  pool: 5

以下是错误跟踪：

/home/naveen/.rvm/rubies/ruby-1.9.3-p448/lib/ruby/1.9.1/psych/visitors/to_ruby.rb:246:in `block in visit_Psych_Nodes_Alias': Unknown alias: production (Psych::BadAlias)
    from /home/naveen/.rvm/rubies/ruby-1.9.3-p448/lib/ruby/1.9.1/psych/visitors/to_ruby.rb:246:in `fetch'
    from /home/naveen/.rvm/rubies/ruby-1.9.3-p448/lib/ruby/1.9.1/psych/visitors/to_ruby.rb:246:in `visit_Psych_Nodes_Alias'
    from /home/naveen/.rvm/rubies/ruby-1.9.3-p448/lib/ruby/1.9.1/psych/visitors/visitor.rb:15:in `visit'
    from /home/naveen/.rvm/rubies/ruby-1.9.3-p448/lib/ruby/1.9.1/psych/visitors/visitor.rb:5:in `accept'
    from /home/naveen/.rvm/rubies/ruby-1.9.3-p448/lib/ruby/1.9.1/psych/visitors/to_ruby.rb:20:in `accept'
    from /home/naveen/.rvm/rubies/ruby-1.9.3-p448/lib/ruby/1.9.1/psych/visitors/to_ruby.rb:264:in `block in revive_hash'
    from /home/naveen/.rvm/rubies/ruby-1.9.3-p448/lib/ruby/1.9.1/psych/visitors/to_ruby.rb:258:in `each'
    from /home/naveen/.rvm/rubies/ruby-1.9.3-p448/lib/ruby/1.9.1/psych/visitors/to_ruby.rb:258:in `each_slice'
    from /home/naveen/.rvm/rubies/ruby-1.9.3-p448/lib/ruby/1.9.1/psych/visitors/to_ruby.rb:258:in `revive_hash'
    from /home/naveen/.rvm/rubies/ruby-1.9.3-p448/lib/ruby/1.9.1/psych/visitors/to_ruby.rb:141:in `visit_Psych_Nodes_Mapping'
    from /home/naveen/.rvm/gems/ruby-1.9.3-p448@EconveyancePro3/gems/delayed_job-4.0.0/lib/delayed/psych_ext.rb:133:in `visit_Psych_Nodes_Mapping_with_class'
    from /home/naveen/.rvm/rubies/ruby-1.9.3-p448/lib/ruby/1.9.1/psych/visitors/visitor.rb:15:in `visit'
    from /home/naveen/.rvm/rubies/ruby-1.9.3-p448/lib/ruby/1.9.1/psych/visitors/visitor.rb:5:in `accept'
    from /home/naveen/.rvm/rubies/ruby-1.9.3-p448/lib/ruby/1.9.1/psych/visitors/to_ruby.rb:20:in `accept'
    from /home/naveen/.rvm/rubies/ruby-1.9.3-p448/lib/ruby/1.9.1/psych/visitors/to_ruby.rb:273:in `block in revive_hash'
    from /home/naveen/.rvm/rubies/ruby-1.9.3-p448/lib/ruby/1.9.1/psych/visitors/to_ruby.rb:258:in `each'
    from /home/naveen/.rvm/rubies/ruby-1.9.3-p448/lib/ruby/1.9.1/psych/visitors/to_ruby.rb:258:in `each_slice'
    from /home/naveen/.rvm/rubies/ruby-1.9.3-p448/lib/ruby/1.9.1/psych/visitors/to_ruby.rb:258:in `revive_hash'
    from /home/naveen/.rvm/rubies/ruby-1.9.3-p448/lib/ruby/1.9.1/psych/visitors/to_ruby.rb:141:in `visit_Psych_Nodes_Mapping'
    from /home/naveen/.rvm/gems/ruby-1.9.3-p448@EconveyancePro3/gems/delayed_job-4.0.0/lib/delayed/psych_ext.rb:133:in `visit_Psych_Nodes_Mapping_with_class'
    from /home/naveen/.rvm/rubies/ruby-1.9.3-p448/lib/ruby/1.9.1/psych/visitors/visitor.rb:15:in `visit'
    from /home/naveen/.rvm/rubies/ruby-1.9.3-p448/lib/ruby/1.9.1/psych/visitors/visitor.rb:5:in `accept'
    from /home/naveen/.rvm/rubies/ruby-1.9.3-p448/lib/ruby/1.9.1/psych/visitors/to_ruby.rb:20:in `accept'
    from /home/naveen/.rvm/rubies/ruby-1.9.3-p448/lib/ruby/1.9.1/psych/visitors/to_ruby.rb:238:in `visit_Psych_Nodes_Document'
    from /home/naveen/.rvm/rubies/ruby-1.9.3-p448/lib/ruby/1.9.1/psych/visitors/visitor.rb:15:in `visit'
    from /home/naveen/.rvm/rubies/ruby-1.9.3-p448/lib/ruby/1.9.1/psych/visitors/visitor.rb:5:in `accept'
    from /home/naveen/.rvm/rubies/ruby-1.9.3-p448/lib/ruby/1.9.1/psych/visitors/to_ruby.rb:20:in `accept'
    from /home/naveen/.rvm/rubies/ruby-1.9.3-p448/lib/ruby/1.9.1/psych/nodes/node.rb:35:in `to_ruby'
    from /home/naveen/.rvm/rubies/ruby-1.9.3-p448/lib/ruby/1.9.1/psych.rb:128:in `load'
    from /home/naveen/.rvm/gems/ruby-1.9.3-p448@EconveyancePro3/gems/railties-3.2.13/lib/rails/application/configuration.rb:115:in `database_configuration'
    from /home/naveen/.rvm/gems/ruby-1.9.3-p448@EconveyancePro3/gems/activerecord-3.2.13/lib/active_record/railtie.rb:78:in `block (2 levels) in <class:Railtie>'
    from /home/naveen/.rvm/gems/ruby-1.9.3-p448@EconveyancePro3/gems/activesupport-3.2.13/lib/active_support/lazy_load_hooks.rb:36:in `instance_eval'
    from /home/naveen/.rvm/gems/ruby-1.9.3-p448@EconveyancePro3/gems/activesupport-3.2.13/lib/active_support/lazy_load_hooks.rb:36:in `execute_hook'
    from /home/naveen/.rvm/gems/ruby-1.9.3-p448@EconveyancePro3/gems/activesupport-3.2.13/lib/active_support/lazy_load_hooks.rb:26:in `block in on_load'
    from /home/naveen/.rvm/gems/ruby-1.9.3-p448@EconveyancePro3/gems/activesupport-3.2.13/lib/active_support/lazy_load_hooks.rb:25:in `each'
    from /home/naveen/.rvm/gems/ruby-1.9.3-p448@EconveyancePro3/gems/activesupport-3.2.13/lib/active_support/lazy_load_hooks.rb:25:in `on_load'
    from /home/naveen/.rvm/gems/ruby-1.9.3-p448@EconveyancePro3/gems/activerecord-3.2.13/lib/active_record/railtie.rb:74:in `block in <class:Railtie>'
    from /home/naveen/.rvm/gems/ruby-1.9.3-p448@EconveyancePro3/gems/railties-3.2.13/lib/rails/initializable.rb:30:in `instance_exec'
    from /home/naveen/.rvm/gems/ruby-1.9.3-p448@EconveyancePro3/gems/railties-3.2.13/lib/rails/initializable.rb:30:in `run'
    from /home/naveen/.rvm/gems/ruby-1.9.3-p448@EconveyancePro3/gems/railties-3.2.13/lib/rails/initializable.rb:55:in `block in run_initializers'
    from /home/naveen/.rvm/gems/ruby-1.9.3-p448@EconveyancePro3/gems/railties-3.2.13/lib/rails/initializable.rb:54:in `each'
    from /home/naveen/.rvm/gems/ruby-1.9.3-p448@EconveyancePro3/gems/railties-3.2.13/lib/rails/initializable.rb:54:in `run_initializers'
    from /home/naveen/.rvm/gems/ruby-1.9.3-p448@EconveyancePro3/gems/railties-3.2.13/lib/rails/application.rb:136:in `initialize!'
    from /home/naveen/.rvm/gems/ruby-1.9.3-p448@EconveyancePro3/gems/railties-3.2.13/lib/rails/railtie/configurable.rb:30:in `method_missing'
    from /home/naveen/workspace/econveyance/EconveyancePro3/config/environment.rb:6:in `<top (required)>'
    from /home/naveen/.rvm/gems/ruby-1.9.3-p448@EconveyancePro3/gems/activesupport-3.2.13/lib/active_support/dependencies.rb:251:in `require'
    from /home/naveen/.rvm/gems/ruby-1.9.3-p448@EconveyancePro3/gems/activesupport-3.2.13/lib/active_support/dependencies.rb:251:in `block in require'
    from /home/naveen/.rvm/gems/ruby-1.9.3-p448@EconveyancePro3/gems/activesupport-3.2.13/lib/active_support/dependencies.rb:236:in `load_dependency'
    from /home/naveen/.rvm/gems/ruby-1.9.3-p448@EconveyancePro3/gems/activesupport-3.2.13/lib/active_support/dependencies.rb:251:in `require'
    from /home/naveen/.rvm/gems/ruby-1.9.3-p448@EconveyancePro3/gems/railties-3.2.13/lib/rails/application.rb:103:in `require_environment!'
    from /home/naveen/.rvm/gems/ruby-1.9.3-p448@EconveyancePro3/gems/railties-3.2.13/lib/rails/commands.rb:40:in `<top (required)>'
    from script/rails:6:in `require'
    from script/rails:6:in `<main>'

  ...

以下是完整的database.yml文件。如果我取消注释注释部分，则会显示此错误。与ruby 1.8.7和rails 2.3.x一样，一切正常。

development: &development
  adapter: mysql2
  database: <%= $dev_main_database %>
  username: root
  password:
  timeout: 60000
  host: <%= $dev_linux_machine_name %>
  encoding: utf8

test:
  adapter: mysql2
  database: ecpmain_test
  username: root
  password:
  timeout: 60000
  host: tecpdb
  encoding: utf8

staging: &staging
  adapter: mysql2
  database: ecpmain_staging
  username: sa
  password: woofer8
  timeout: 60000
  host: <%= $staging_database_host %>
  encoding: utf8

production: &development
  adapter: mysql2
  database: <%= $dev_main_database %>
  username: root
  password:
  timeout: 60000
  host: <%= $dev_linux_machine_name %>
  encoding: utf8

# background_process_development:
#   <<: *development

# background_process_staging:
#   <<: *staging

# background_process_production:
#   <<: *production

doc_finals_development: &doc_finals_development
  adapter: mysql2
  database: <%= $dev_docs_database %>
  username: sa
  password: woofer8
  timeout: 60000
  host: <%= $dev_linux_machine_name %>
  encoding: utf8

doc_finals_test:
  adapter: mysql2
  database: ecpdocs_test
  username: sa
  password: woofer8
  timeout: 60000
  host: tecpdb
  encoding: utf8

doc_finals_staging: &doc_finals_staging
  adapter: mysql2
  database: ecpdocs_staging
  username: sa
  password: woofer8
  timeout: 60000
  host: <%= $staging_database_host %>
  encoding: utf8

doc_finals_production: &doc_finals_production
  adapter: mysql2
  database: ecpdocs_production
  username: sa
  password: nash!@w
  timeout: 60000
  host: pecpdb3
  encoding: utf8

# doc_finals_background_process_development:
#   <<: *doc_finals_development

# doc_finals_background_process_staging:
#   <<: *doc_finals_staging

# doc_finals_background_process_production:
#   <<: *doc_finals_production

logging_development: &logging_development
  adapter: mysql2
  database: <%= $dev_logging_database %>
  username: sa
  password: woofer8
  timeout: 60000
  host: <%= $dev_linux_machine_name %>
  encoding: utf8

logging_test:
  adapter: mysql2
  database: ecplogging_test
  username: sa
  password: woofer8
  timeout: 60000
  host: tecpdb
  encoding: utf8

logging_staging: &logging_staging
  adapter: mysql2
  database: ecplogging_staging
  username: sa
  password: woofer8
  timeout: 60000
  host: <%= $staging_database_host %>
  encoding: utf8

logging_production: &logging_production
  adapter: mysql2
  database: ecplogging_production
  username: sa
  password: nash!@w
  timeout: 60000
  host: pecpdb3
  encoding: utf8

# logging_background_process_development:
#   <<: *logging_development

# logging_background_process_staging:
#   <<: *logging_staging

# logging_background_process_production:
#   <<: *logging_production

Answer 1

我发现你的语法没有问题。您发布的错误似乎表明您在某处错误地执行了此操作：

development:
  << *production
  pool: 5

您可以发布有问题的完整database.yml文件吗？尽可能多地编辑它，但我认为问题出在未发布的数据中。

修改

我是对的，你试图让生产继承自一个不存在的块：

production: &development
  ...

我没有尝试验证，但可能是ruby 1.8的YAML解析器对这些类型的错误更加宽容。

无论如何，我继续为你干掉那个文件，并确保它正确解析：

defaults: &defaults
  adapter: mysql2
  username: root
  password:
  timeout: 60000
  encoding: utf8

development: &development
  <<: *defaults
  database: <%= $dev_main_database %>
  host: <%= $dev_linux_machine_name %>

test:
  <<: *defaults
  host: tecpdb
  database: ecpmain_test

staging: &staging
  <<: *defaults
  database: ecpmain_staging
  username: sa
  password: woofer8
  host: <%= $staging_database_host %>

production: &production
  <<: *defaults
  database: <%= $dev_main_database %>
  host: <%= $dev_linux_machine_name %>

background_process_development:
  <<: *development

background_process_staging:
  <<: *staging

background_process_production:
  <<: *production

doc_finals_defaults: &doc_finals_defaults
  adapter: mysql2
  username: sa
  password: woofer8
  timeout: 60000
  encoding: utf8

doc_finals_development: &doc_finals_development
  <<: *doc_finals_defaults
  database: <%= $dev_docs_database %>
  host: <%= $dev_linux_machine_name %>

doc_finals_test:
  <<: *doc_finals_defaults
  database: ecpdocs_test
  host: tecpdb

doc_finals_staging: &doc_finals_staging
  <<: *doc_finals_defaults
  adapter: mysql2
  database: ecpdocs_staging
  host: <%= $staging_database_host %>

doc_finals_production: &doc_finals_production
  <<: *doc_finals_defaults
  database: ecpdocs_production
  username: sa
  password: nash!@w
  host: pecpdb3

doc_finals_background_process_development:
  <<: *doc_finals_development

doc_finals_background_process_staging:
  <<: *doc_finals_staging

doc_finals_background_process_production:
  <<: *doc_finals_production

logging_defaults: &logging_defaults
  adapter: mysql2
  username: sa
  password: woofer8
  timeout: 60000
  encoding: utf8

logging_development: &logging_development
  <<: *logging_defaults
  database: <%= $dev_logging_database %>
  host: <%= $dev_linux_machine_name %>

logging_test:
  <<: *logging_defaults
  database: ecplogging_test
  host: tecpdb

logging_staging: &logging_staging
  <<: *logging_defaults
  database: ecplogging_staging
  host: <%= $staging_database_host %>

logging_production: &logging_production
  <<: *logging_defaults
  database: ecplogging_production
  username: sa
  password: nash!@w
  host: pecpdb3

logging_background_process_development:
  <<: *logging_development

logging_background_process_staging:
  <<: *logging_staging

logging_background_process_production:
  <<: *logging_production

Answer 2

我当时使用defaults，问题出在爱上。

Answer 3

我遇到了同样的错误，但错误的别名是 INSERT INTO Sabbath School VALUES (number 1, hello, great, google.com, google.com), 而不是 development

我解决这个问题的方法是在我的 production 文件中注释以下几行

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