我一再尝试使用nginx和unicorn在ec2实例上设置我的rails应用程序。我发现nginx和unicorn都设置正确;但是，在这两台机器上我的rails应用程序不想在生产环境中启动。尝试启动生产的输出是：
/Users/benvreed/.rbenv/versions/1.9.3-p327/lib/ruby/gems/1.9.1/gems/activerecord-3.2.8/lib/active_record/connection_adapters/abstract/connection_specification.rb:47:in `resolve_hash_connection': database configuration does not specify adapter (ActiveRecord::AdapterNotSpecified)
from /Users/benvreed/.rbenv/versions/1.9.3-p327/lib/ruby/gems/1.9.1/gems/activerecord-3.2.8/lib/active_record/connection_adapters/abstract/connection_specification.rb:41:in `resolve_string_connection'
from /Users/benvreed/.rbenv/versions/1.9.3-p327/lib/ruby/gems/1.9.1/gems/activerecord-3.2.8/lib/active_record/connection_adapters/abstract/connection_specification.rb:25:in `spec'
from /Users/benvreed/.rbenv/versions/1.9.3-p327/lib/ruby/gems/1.9.1/gems/activerecord-3.2.8/lib/active_record/connection_adapters/abstract/connection_specification.rb:129:in `establish_connection'
from /Users/benvreed/.rbenv/versions/1.9.3-p327/lib/ruby/gems/1.9.1/gems/activerecord-3.2.8/lib/active_record/railtie.rb:82:in `block (2 levels) in <class:Railtie>'
from /Users/benvreed/.rbenv/versions/1.9.3-p327/lib/ruby/gems/1.9.1/gems/activesupport-3.2.8/lib/active_support/lazy_load_hooks.rb:36:in `instance_eval'
from /Users/benvreed/.rbenv/versions/1.9.3-p327/lib/ruby/gems/1.9.1/gems/activesupport-3.2.8/lib/active_support/lazy_load_hooks.rb:36:in `execute_hook'
from /Users/benvreed/.rbenv/versions/1.9.3-p327/lib/ruby/gems/1.9.1/gems/activesupport-3.2.8/lib/active_support/lazy_load_hooks.rb:26:in `block in on_load'
from /Users/benvreed/.rbenv/versions/1.9.3-p327/lib/ruby/gems/1.9.1/gems/activesupport-3.2.8/lib/active_support/lazy_load_hooks.rb:25:in `each'
from /Users/benvreed/.rbenv/versions/1.9.3-p327/lib/ruby/gems/1.9.1/gems/activesupport-3.2.8/lib/active_support/lazy_load_hooks.rb:25:in `on_load'
from /Users/benvreed/.rbenv/versions/1.9.3-p327/lib/ruby/gems/1.9.1/gems/activerecord-3.2.8/lib/active_record/railtie.rb:74:in `block in <class:Railtie>'
from /Users/benvreed/.rbenv/versions/1.9.3-p327/lib/ruby/gems/1.9.1/gems/railties-3.2.8/lib/rails/initializable.rb:30:in `instance_exec'
from /Users/benvreed/.rbenv/versions/1.9.3-p327/lib/ruby/gems/1.9.1/gems/railties-3.2.8/lib/rails/initializable.rb:30:in `run'
from /Users/benvreed/.rbenv/versions/1.9.3-p327/lib/ruby/gems/1.9.1/gems/railties-3.2.8/lib/rails/initializable.rb:55:in `block in run_initializers'
from /Users/benvreed/.rbenv/versions/1.9.3-p327/lib/ruby/gems/1.9.1/gems/railties-3.2.8/lib/rails/initializable.rb:54:in `each'
from /Users/benvreed/.rbenv/versions/1.9.3-p327/lib/ruby/gems/1.9.1/gems/railties-3.2.8/lib/rails/initializable.rb:54:in `run_initializers'
from /Users/benvreed/.rbenv/versions/1.9.3-p327/lib/ruby/gems/1.9.1/gems/railties-3.2.8/lib/rails/application.rb:136:in `initialize!'
from /Users/benvreed/.rbenv/versions/1.9.3-p327/lib/ruby/gems/1.9.1/gems/railties-3.2.8/lib/rails/railtie/configurable.rb:30:in `method_missing'
from /Users/benvreed/Documents/rubydev/StudyPublic/config/environment.rb:5:in `<top (required)>'
from /Users/benvreed/.rbenv/versions/1.9.3-p327/lib/ruby/gems/1.9.1/gems/activesupport-3.2.8/lib/active_support/dependencies.rb:251:in `require'
from /Users/benvreed/.rbenv/versions/1.9.3-p327/lib/ruby/gems/1.9.1/gems/activesupport-3.2.8/lib/active_support/dependencies.rb:251:in `block in require'
from /Users/benvreed/.rbenv/versions/1.9.3-p327/lib/ruby/gems/1.9.1/gems/activesupport-3.2.8/lib/active_support/dependencies.rb:236:in `load_dependency'
from /Users/benvreed/.rbenv/versions/1.9.3-p327/lib/ruby/gems/1.9.1/gems/activesupport-3.2.8/lib/active_support/dependencies.rb:251:in `require'
from /Users/benvreed/Documents/rubydev/StudyPublic/config.ru:4:in `block in <main>'
from /Users/benvreed/.rbenv/versions/1.9.3-p327/lib/ruby/gems/1.9.1/gems/rack-1.4.1/lib/rack/builder.rb:51:in `instance_eval'
from /Users/benvreed/.rbenv/versions/1.9.3-p327/lib/ruby/gems/1.9.1/gems/rack-1.4.1/lib/rack/builder.rb:51:in `initialize'
from /Users/benvreed/Documents/rubydev/StudyPublic/config.ru:1:in `new'
from /Users/benvreed/Documents/rubydev/StudyPublic/config.ru:1:in `<main>'
from /Users/benvreed/.rbenv/versions/1.9.3-p327/lib/ruby/gems/1.9.1/gems/rack-1.4.1/lib/rack/builder.rb:40:in `eval'
from /Users/benvreed/.rbenv/versions/1.9.3-p327/lib/ruby/gems/1.9.1/gems/rack-1.4.1/lib/rack/builder.rb:40:in `parse_file'
from /Users/benvreed/.rbenv/versions/1.9.3-p327/lib/ruby/gems/1.9.1/gems/rack-1.4.1/lib/rack/server.rb:200:in `app'
from /Users/benvreed/.rbenv/versions/1.9.3-p327/lib/ruby/gems/1.9.1/gems/railties-3.2.8/lib/rails/commands/server.rb:46:in `app'
from /Users/benvreed/.rbenv/versions/1.9.3-p327/lib/ruby/gems/1.9.1/gems/rack-1.4.1/lib/rack/server.rb:301:in `wrapped_app'
from /Users/benvreed/.rbenv/versions/1.9.3-p327/lib/ruby/gems/1.9.1/gems/rack-1.4.1/lib/rack/server.rb:252:in `start'
from /Users/benvreed/.rbenv/versions/1.9.3-p327/lib/ruby/gems/1.9.1/gems/railties-3.2.8/lib/rails/commands/server.rb:70:in `start'
from /Users/benvreed/.rbenv/versions/1.9.3-p327/lib/ruby/gems/1.9.1/gems/railties-3.2.8/lib/rails/commands.rb:55:in `block in <top (required)>'
from /Users/benvreed/.rbenv/versions/1.9.3-p327/lib/ruby/gems/1.9.1/gems/railties-3.2.8/lib/rails/commands.rb:50:in `tap'
from /Users/benvreed/.rbenv/versions/1.9.3-p327/lib/ruby/gems/1.9.1/gems/railties-3.2.8/lib/rails/commands.rb:50:in `<top (required)>'
from script/rails:6:in `require'
from script/rails:6:in `<main>'
虽然，我明确地在我的database.yml文件中指定了postgresql适配器：
# PostgreSQL. Versions 8.2 and up are supported.
#
# Install the pg driver:
# gem install pg
# On Mac OS X with macports:
# gem install pg -- --with-pg-config=/opt/local/lib/postgresql84/bin/pg_config
# On Windows:
# gem install pg
# Choose the win32 build.
# Install PostgreSQL and put its /bin directory on your path.
#
# Configure Using Gemfile
# gem 'pg'
#
development:
adapter: postgresql
encoding: unicode
host: localhost
database: study_development
pool: 5
# Connect on a TCP socket. Omitted by default since the client uses a
# domain socket that doesn't need configuration. Windows does not have
# domain sockets, so uncomment these lines.
#host: localhost
#port: 5432
# Schema search path. The server defaults to $user,public
#schema_search_path: myapp,sharedapp,public
# Minimum log levels, in increasing order:
# debug5, debug4, debug3, debug2, debug1,
# log, notice, warning, error, fatal, and panic
# The server defaults to notice.
#min_messages: warning
# Warning: The database defined as "test" will be erased and
# re-generated from your development database when you run "rake".
# Do not set this db to the same as development or production.
test:
adapter: postgresql
encoding: unicode
host: localhost
database: study_test
pool: 5
production:
adapter: postgresql
encoding: unicode
host: localhost
database: study_production
pool: 5
真正奇怪的是它在开发和测试环境中都能成功运行。我已经检查了StackOverflow上的其他问题，大多数人都说这是一个间距问题;但是，我已经多次重做database.yml文件，结果相同。
我的独角兽和nginx文件是标准配置。
非常感谢任何帮助。我一直站着不动，直到这个运行。提前谢谢。
RAILS_ENV
通过执行RAILS_ENV=production rails c使用Rails控制台时，运行RAILS_ENV会产生：
NameError: uninitialized constant RAILS_ENV
from (irb):1
from /Users/benvreed/.rbenv/versions/1.9.3-p327/lib/ruby/gems/1.9.1/gems/railties-3.2.8/lib/rails/commands/console.rb:47:in `start'
from /Users/benvreed/.rbenv/versions/1.9.3-p327/lib/ruby/gems/1.9.1/gems/railties-3.2.8/lib/rails/commands/console.rb:8:in `start'
from /Users/benvreed/.rbenv/versions/1.9.3-p327/lib/ruby/gems/1.9.1/gems/railties-3.2.8/lib/rails/commands.rb:41:in `<top (required)>'
from script/rails:6:in `require'
from script/rails:6:in `<main>'
Rails.env产生：
=> "production"
答案 0 :(得分：1)
database.yml中的适配器应该是pg，而不是postgresql。
production:
adapter: pg
encoding: unicode
host: localhost
database: study_development
答案 1 :(得分：0)
我的设置使用了这个：
production:
adapter: pg
encoding: utf8
reconnect: false
database: my_app_name_production
答案 2 :(得分：0)
您的database.yml设置没问题。没什么奇怪的。
如果开发模式无异常运行，则问题不在DB中。
尝试精确检查database.yml：可能存在无效/不可接受的*字符。
答案 3 :(得分：0)
分叉错误！ 可能是一些缓存或日志问题它表明我们的代码中没有任何错误。
我的团队解决了。
删除项目
git克隆项目
配置database.yml
启动服务器
一切都还可以！
错误消失的同一个项目！ 所以我们认为它是环境问题或者cach或log。