rails server的问题

Question

我刚刚开始使用rails和heroku上的ruby。我正在关注herokus网站上的入门指南，但遇到了问题。我已经登录到heroku，创建了一个应用程序，如rails new myapp --database=postgresql，然后在app/views/welcome/index.html.erb中创建了一个控制器rails generate controller welcome index，我刚刚创建了一个名为hello world的标题。当我启动一个本地服务器并转到它，我得到could not connect to server: No such file or directory Is the server running locally and accepting connections on Unix domain socket "/tmp/.s.PGSQL.5432"?和输出在下面列出的终端，我跟着另一个教程只是为了设置轨道没有heroku，并创建了这样的应用程序rails new blog，然后做同样的创建一个控制器在heroku教程和一切正常，所以我认为这个问题是rails new myapp --database=postgresql我该如何解决这个问题？

PG::ConnectionBad (could not connect to server: No such file or directory 
    Is the server running locally and accepting 
    connections on Unix domain socket "/tmp/.s.PGSQL.5432"? 
): 
    activerecord (4.0.2) lib/active_record/connection_adapters/postgresql_adapter.rb:831:in `initialize' 
    activerecord (4.0.2) lib/active_record/connection_adapters/postgresql_adapter.rb:831:in `new' 
    activerecord (4.0.2) lib/active_record/connection_adapters/postgresql_adapter.rb:831:in `connect' 
    activerecord (4.0.2) lib/active_record/connection_adapters/postgresql_adapter.rb:548:in `initialize' 
    activerecord (4.0.2) lib/active_record/connection_adapters/postgresql_adapter.rb:41:in `new' 
    activerecord (4.0.2) lib/active_record/connection_adapters/postgresql_adapter.rb:41:in `postgresql_connection' 
    activerecord (4.0.2) lib/active_record/connection_adapters/abstract/connection_pool.rb:440:in `new_connection' 
    activerecord (4.0.2) lib/active_record/connection_adapters/abstract/connection_pool.rb:450:in `checkout_new_connection' 
    activerecord (4.0.2) lib/active_record/connection_adapters/abstract/connection_pool.rb:421:in `acquire_connection' 
    activerecord (4.0.2) lib/active_record/connection_adapters/abstract/connection_pool.rb:356:in `block in checkout' 
    /Users/mattmoss/.rbenv/versions/2.1.0/lib/ruby/2.1.0/monitor.rb:211:in `mon_synchronize' 
    activerecord (4.0.2) lib/active_record/connection_adapters/abstract/connection_pool.rb:355:in `checkout' 
    activerecord (4.0.2) lib/active_record/connection_adapters/abstract/connection_pool.rb:265:in `block in connection' 
    /Users/mattmoss/.rbenv/versions/2.1.0/lib/ruby/2.1.0/monitor.rb:211:in `mon_synchronize' 
    activerecord (4.0.2) lib/active_record/connection_adapters/abstract/connection_pool.rb:264:in `connection' 
    activerecord (4.0.2) lib/active_record/connection_adapters/abstract/connection_pool.rb:546:in `retrieve_connection' 
    activerecord (4.0.2) lib/active_record/connection_handling.rb:79:in `retrieve_connection' 
    activerecord (4.0.2) lib/active_record/connection_handling.rb:53:in `connection' 
    activerecord (4.0.2) lib/active_record/query_cache.rb:51:in `restore_query_cache_settings' 
    activerecord (4.0.2) lib/active_record/query_cache.rb:43:in `rescue in call' 
    activerecord (4.0.2) lib/active_record/query_cache.rb:32:in `call' 
    activerecord (4.0.2) lib/active_record/connection_adapters/abstract/connection_pool.rb:626:in `call' 
    activerecord (4.0.2) lib/active_record/migration.rb:369:in `call' 
    actionpack (4.0.2) lib/action_dispatch/middleware/callbacks.rb:29:in `block in call' 
    activesupport (4.0.2) lib/active_support/callbacks.rb:373:in `_run__4242016335734095215__call__callbacks' 
    activesupport (4.0.2) lib/active_support/callbacks.rb:80:in `run_callbacks' 
    actionpack (4.0.2) lib/action_dispatch/middleware/callbacks.rb:27:in `call' 
    actionpack (4.0.2) lib/action_dispatch/middleware/reloader.rb:64:in `call' 
    actionpack (4.0.2) lib/action_dispatch/middleware/remote_ip.rb:76:in `call' 
    actionpack (4.0.2) lib/action_dispatch/middleware/debug_exceptions.rb:17:in `call' 
    actionpack (4.0.2) lib/action_dispatch/middleware/show_exceptions.rb:30:in `call' 
    railties (4.0.2) lib/rails/rack/logger.rb:38:in `call_app' 
    railties (4.0.2) lib/rails/rack/logger.rb:20:in `block in call' 
    activesupport (4.0.2) lib/active_support/tagged_logging.rb:67:in `block in tagged' 
    activesupport (4.0.2) lib/active_support/tagged_logging.rb:25:in `tagged' 
    activesupport (4.0.2) lib/active_support/tagged_logging.rb:67:in `tagged' 
    railties (4.0.2) lib/rails/rack/logger.rb:20:in `call' 
    actionpack (4.0.2) lib/action_dispatch/middleware/request_id.rb:21:in `call' 
    rack (1.5.2) lib/rack/methodoverride.rb:21:in `call' 
    rack (1.5.2) lib/rack/runtime.rb:17:in `call' 
    activesupport (4.0.2) lib/active_support/cache/strategy/local_cache.rb:83:in `call' 
    rack (1.5.2) lib/rack/lock.rb:17:in `call' 
    actionpack (4.0.2) lib/action_dispatch/middleware/static.rb:64:in `call' 
    rack (1.5.2) lib/rack/sendfile.rb:112:in `call' 
    railties (4.0.2) lib/rails/engine.rb:511:in `call' 
    railties (4.0.2) lib/rails/application.rb:97:in `call' 
    rack (1.5.2) lib/rack/lock.rb:17:in `call' 
    rack (1.5.2) lib/rack/content_length.rb:14:in `call' 
    rack (1.5.2) lib/rack/handler/webrick.rb:60:in `service' 
    /Users/mattmoss/.rbenv/versions/2.1.0/lib/ruby/2.1.0/webrick/httpserver.rb:138:in `service' 
    /Users/mattmoss/.rbenv/versions/2.1.0/lib/ruby/2.1.0/webrick/httpserver.rb:94:in `run' 
    /Users/mattmoss/.rbenv/versions/2.1.0/lib/ruby/2.1.0/webrick/server.rb:295:in `block in start_thread' 


    Rendered /Users/mattmoss/.rbenv/versions/2.1.0/lib/ruby/gems/2.1.0/gems/actionpack-4.0.2/lib/action_dispatch/middleware/templates/rescues/_source.erb (0.5ms) 
    Rendered /Users/mattmoss/.rbenv/versions/2.1.0/lib/ruby/gems/2.1.0/gems/actionpack-4.0.2/lib/action_dispatch/middleware/templates/rescues/_trace.erb (1.0ms) 
    Rendered /Users/mattmoss/.rbenv/versions/2.1.0/lib/ruby/gems/2.1.0/gems/actionpack-4.0.2/lib/action_dispatch/middleware/templates/rescues/_request_and_response.erb (1.0ms) 
    Rendered /Users/mattmoss/.rbenv/versions/2.1.0/lib/ruby/gems/2.1.0/gems/actionpack-4.0.2/lib/action_dispatch/middleware/templates/rescues/diagnostics.erb within rescues/layout (18.2ms) 

这里是我的database.yml

# PostgreSQL. Versions 8.2 and up are supported. 
# 
# Install the pg driver: 
# gem install pg 
# On OS X with Homebrew: 
# gem install pg -- --with-pg-config=/usr/local/bin/pg_config 
# On 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 
    database: myapp_development 
    pool: 5 
    password: 

    # 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 

    # The TCP port the server listens on. Defaults to 5432. 
    # If your server runs on a different port number, change accordingly. 
    #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 
    # Defaults to warning. 
    #min_messages: notice 

# 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 
    database: myapp_test 
    pool: 5 
    password: 

production: 
    adapter: postgresql 
    encoding: unicode 
    database: myapp_production 
    pool: 5 
    password: 

development: 
    host: localhost 

test: 
    host: localhost 

Answer 1

在你config/database.yml，尝试添加

host: localhost 

在每个开发和测试环境或

更具体看着所示现有config/database.yml以上：

development: 
    adapter: postgresql 
    encoding: unicode 
    database: myapp_development 
    pool: 5 
    password: 
    host: localhost 

test: 
    adapter: postgresql 
    encoding: unicode 
    database: myapp_test 
    pool: 5 
    password: 
    host: localhost 

希望这会有所帮助

Answer 2

在大多数* nix服务器上，“localhost”是通过Unix风格套接字处理的。如果您使用127.0.0.1，它将使用TCP/IP。尝试一下，或者确保你的客户端和服务器使用相同的套接字地址，并且它实际上是一个可用的* nix套接字。

database.yml中有一个配置参数，可以让你设置套接字地址，确保你也可以访问目录。

Answer 3

我听说Heroku对db连接行为做了一些修改。对于rails版本> = 4.1，它不覆盖你的config/database.yml - 它与它合并。首先你需要访问https://postgres.heroku.com/databases并点击你的数据库。你应该看看该参数在PIC下面

使用该变量为您的生产参数，像这样

production: 
    adapter: postgresql 
    url: <%= ENV['HEROKU_POSTGRESQL_BLACK_URL'] %> 

这是我尝试不同的事情后，什么工作。我希望这可以帮助别人。