Rails / Postgres 连接问题（psql 和 pg 工作正常）
Rails / Postgres connection issue (psql and pg working fine)
我的 rails 应用程序连接到我的开发机器上的数据库，并且在生产环境中运行良好。我已将项目克隆到同事的机器上，并从 pgdump 本地重新创建数据库。同样的过程在我的机器上运行良好。但是在他身上，
psql 在命令行没有问题：
$ psql ROL2
psql (9.5.2)
Type "help" for help.
ROL2=#
为了测试 pg gem (pg-0.18.4)，我写了一个简单的 ruby 脚本来输出我们的用户名：
#!/usr/bin/env ruby
require 'pg'
conn = PG.connect( dbname: 'ROL2' )
conn.exec( "SELECT * FROM users" ) do |result|
result.each do |row|
puts "#{row['first_name']} #{row['last_name']}"
end
end
没问题；工作正常。但是当我尝试通过 rails 控制台或应用程序中的任务连接时：
$ rails db
psql: server closed the connection unexpectedly
This probably means the server terminated abnormally
before or while processing the request.
这是database.yml：
# LOCAL POSTGRES
development:
adapter: postgresql
encoding: utf8
host: localhost
port: 5432
database: ROL2
pool: 5
当我尝试与客户端 (Postico) 连接时也是如此。我试过 postgres 用户和他的用户名/密码。
ROL2=# \du
List of roles
Role name | Attributes | Member of
-------------+------------------------------------------------------------+-----------
joeschmo | Superuser, Create role, Create DB | {}
postgres | Superuser, Create role, Create DB, Replication, Bypass RLS | {}
即使 psql 和 pg gem 工作正常，为什么 Rails 可能无法连接到数据库？
已添加：出现在 Rails 开发日志中的错误：
PG::ConnectionBad (server closed the connection unexpectedly
This probably means the server terminated abnormally
before or while processing the request.
):
activerecord (4.2.4) lib/active_record/connection_adapters/postgresql_adapter.rb:655:in `initialize'
activerecord (4.2.4) lib/active_record/connection_adapters/postgresql_adapter.rb:655:in `new'
activerecord (4.2.4) lib/active_record/connection_adapters/postgresql_adapter.rb:655:in `connect'
activerecord (4.2.4) lib/active_record/connection_adapters/postgresql_adapter.rb:242:in `initialize'
activerecord (4.2.4) lib/active_record/connection_adapters/postgresql_adapter.rb:44:in `new'
activerecord (4.2.4) lib/active_record/connection_adapters/postgresql_adapter.rb:44:in `postgresql_connection'
activerecord (4.2.4) lib/active_record/connection_adapters/abstract/connection_pool.rb:438:in `new_connection'
activerecord (4.2.4) lib/active_record/connection_adapters/abstract/connection_pool.rb:448:in `checkout_new_connection'
activerecord (4.2.4) lib/active_record/connection_adapters/abstract/connection_pool.rb:422:in `acquire_connection'
activerecord (4.2.4) lib/active_record/connection_adapters/abstract/connection_pool.rb:349:in `block in checkout'
/Users/mac_osx_username/.rvm/rubies/ruby-2.2.3/lib/ruby/2.2.0/monitor.rb:211:in `mon_synchronize'
activerecord (4.2.4) lib/active_record/connection_adapters/postgresql_adapter.rb:655:in `new'
activerecord (4.2.4) lib/active_record/connection_adapters/postgresql_adapter.rb:655:in `connect'
activerecord (4.2.4) lib/active_record/connection_adapters/postgresql_adapter.rb:242:in `initialize'
activerecord (4.2.4) lib/active_record/connection_adapters/postgresql_adapter.rb:44:in `new'
activerecord (4.2.4) lib/active_record/connection_adapters/postgresql_adapter.rb:44:in `postgresql_connection'
activerecord (4.2.4) lib/active_record/connection_adapters/abstract/connection_pool.rb:438:in `new_connection'
activerecord (4.2.4) lib/active_record/connection_adapters/abstract/connection_pool.rb:448:in `checkout_new_connection'
activerecord (4.2.4) lib/active_record/connection_adapters/abstract/connection_pool.rb:422:in `acquire_connection'
activerecord (4.2.4) lib/active_record/connection_adapters/abstract/connection_pool.rb:349:in `block in checkout'
/Users/mac_osx_username/.rvm/rubies/ruby-2.2.3/lib/ruby/2.2.0/monitor.rb:211:in `mon_synchronize'
activerecord (4.2.4) lib/active_record/connection_adapters/abstract/connection_pool.rb:348:in `checkout'
activerecord (4.2.4) lib/active_record/connection_adapters/abstract/connection_pool.rb:263:in `block in connection'
/Users/mac_osx_username/.rvm/rubies/ruby-2.2.3/lib/ruby/2.2.0/monitor.rb:211:in `mon_synchronize'
activerecord (4.2.4) lib/active_record/connection_adapters/abstract/connection_pool.rb:262:in `connection'
activerecord (4.2.4) lib/active_record/connection_adapters/abstract/connection_pool.rb:571:in `retrieve_connection'
activerecord (4.2.4) lib/active_record/connection_handling.rb:113:in `retrieve_connection'
activerecord (4.2.4) lib/active_record/connection_handling.rb:87:in `connection'
activerecord (4.2.4) lib/active_record/migration.rb:383:in `connection'
activerecord (4.2.4) lib/active_record/migration.rb:370:in `call'
actionpack (4.2.4) lib/action_dispatch/middleware/callbacks.rb:29:in `block in call'
activesupport (4.2.4) lib/active_support/callbacks.rb:88:in `__run_callbacks__'
activesupport (4.2.4) lib/active_support/callbacks.rb:778:in `_run_call_callbacks'
activesupport (4.2.4) lib/active_support/callbacks.rb:81:in `run_callbacks'
actionpack (4.2.4) lib/action_dispatch/middleware/callbacks.rb:27:in `call'
actionpack (4.2.4) lib/action_dispatch/middleware/reloader.rb:73:in `call'
actionpack (4.2.4) lib/action_dispatch/middleware/remote_ip.rb:78:in `call'
actionpack (4.2.4) lib/action_dispatch/middleware/debug_exceptions.rb:17:in `call'
web-console (2.2.1) lib/web_console/middleware.rb:39:in `call'
actionpack (4.2.4) lib/action_dispatch/middleware/show_exceptions.rb:30:in `call'
railties (4.2.4) lib/rails/rack/logger.rb:38:in `call_app'
railties (4.2.4) lib/rails/rack/logger.rb:20:in `block in call'
activesupport (4.2.4) lib/active_support/tagged_logging.rb:68:in `block in tagged'
activesupport (4.2.4) lib/active_support/tagged_logging.rb:26:in `tagged'
activesupport (4.2.4) lib/active_support/tagged_logging.rb:68:in `tagged'
railties (4.2.4) lib/rails/rack/logger.rb:20:in `call'
quiet_assets (1.1.0) lib/quiet_assets.rb:27:in `call_with_quiet_assets'
actionpack (4.2.4) lib/action_dispatch/middleware/request_id.rb:21:in `call'
rack (1.6.4) lib/rack/methodoverride.rb:22:in `call'
rack (1.6.4) lib/rack/runtime.rb:18:in `call'
activesupport (4.2.4) lib/active_support/cache/strategy/local_cache_middleware.rb:28:in `call'
rack (1.6.4) lib/rack/lock.rb:17:in `call'
actionpack (4.2.4) lib/action_dispatch/middleware/static.rb:116:in `call'
rack (1.6.4) lib/rack/sendfile.rb:113:in `call'
railties (4.2.4) lib/rails/engine.rb:518:in `call'
railties (4.2.4) lib/rails/application.rb:165:in `call'
rack (1.6.4) lib/rack/lock.rb:17:in `call'
rack (1.6.4) lib/rack/content_length.rb:15:in `call'
rack (1.6.4) lib/rack/handler/webrick.rb:88:in `service'
由于 database.yml 包括主机和端口，Rails 可能正在尝试连接到 TCP 套接字，而您通过 psql 和 pg 的连接（因为它们不指定主机或端口）正在使用 UNIX 套接字。 PostgreSQL 开箱即用地配置为 不 侦听 TCP 套接字，因此请查看 postgresql.conf 并确保它已取消注释 listen_addresses。如果没有，您可以尝试从 database.yml 中取出主机和端口，或者修改配置以启用 TCP 连接并重新启动 PostgreSQL。
我的 rails 应用程序连接到我的开发机器上的数据库，并且在生产环境中运行良好。我已将项目克隆到同事的机器上，并从 pgdump 本地重新创建数据库。同样的过程在我的机器上运行良好。但是在他身上，
psql 在命令行没有问题：
$ psql ROL2
psql (9.5.2)
Type "help" for help.
ROL2=#
为了测试 pg gem (pg-0.18.4)，我写了一个简单的 ruby 脚本来输出我们的用户名：
#!/usr/bin/env ruby
require 'pg'
conn = PG.connect( dbname: 'ROL2' )
conn.exec( "SELECT * FROM users" ) do |result|
result.each do |row|
puts "#{row['first_name']} #{row['last_name']}"
end
end
没问题；工作正常。但是当我尝试通过 rails 控制台或应用程序中的任务连接时：
$ rails db
psql: server closed the connection unexpectedly
This probably means the server terminated abnormally
before or while processing the request.
这是database.yml：
# LOCAL POSTGRES
development:
adapter: postgresql
encoding: utf8
host: localhost
port: 5432
database: ROL2
pool: 5
当我尝试与客户端 (Postico) 连接时也是如此。我试过 postgres 用户和他的用户名/密码。
ROL2=# \du
List of roles
Role name | Attributes | Member of
-------------+------------------------------------------------------------+-----------
joeschmo | Superuser, Create role, Create DB | {}
postgres | Superuser, Create role, Create DB, Replication, Bypass RLS | {}
即使 psql 和 pg gem 工作正常，为什么 Rails 可能无法连接到数据库？
已添加：出现在 Rails 开发日志中的错误：
PG::ConnectionBad (server closed the connection unexpectedly
This probably means the server terminated abnormally
before or while processing the request.
):
activerecord (4.2.4) lib/active_record/connection_adapters/postgresql_adapter.rb:655:in `initialize'
activerecord (4.2.4) lib/active_record/connection_adapters/postgresql_adapter.rb:655:in `new'
activerecord (4.2.4) lib/active_record/connection_adapters/postgresql_adapter.rb:655:in `connect'
activerecord (4.2.4) lib/active_record/connection_adapters/postgresql_adapter.rb:242:in `initialize'
activerecord (4.2.4) lib/active_record/connection_adapters/postgresql_adapter.rb:44:in `new'
activerecord (4.2.4) lib/active_record/connection_adapters/postgresql_adapter.rb:44:in `postgresql_connection'
activerecord (4.2.4) lib/active_record/connection_adapters/abstract/connection_pool.rb:438:in `new_connection'
activerecord (4.2.4) lib/active_record/connection_adapters/abstract/connection_pool.rb:448:in `checkout_new_connection'
activerecord (4.2.4) lib/active_record/connection_adapters/abstract/connection_pool.rb:422:in `acquire_connection'
activerecord (4.2.4) lib/active_record/connection_adapters/abstract/connection_pool.rb:349:in `block in checkout'
/Users/mac_osx_username/.rvm/rubies/ruby-2.2.3/lib/ruby/2.2.0/monitor.rb:211:in `mon_synchronize'
activerecord (4.2.4) lib/active_record/connection_adapters/postgresql_adapter.rb:655:in `new'
activerecord (4.2.4) lib/active_record/connection_adapters/postgresql_adapter.rb:655:in `connect'
activerecord (4.2.4) lib/active_record/connection_adapters/postgresql_adapter.rb:242:in `initialize'
activerecord (4.2.4) lib/active_record/connection_adapters/postgresql_adapter.rb:44:in `new'
activerecord (4.2.4) lib/active_record/connection_adapters/postgresql_adapter.rb:44:in `postgresql_connection'
activerecord (4.2.4) lib/active_record/connection_adapters/abstract/connection_pool.rb:438:in `new_connection'
activerecord (4.2.4) lib/active_record/connection_adapters/abstract/connection_pool.rb:448:in `checkout_new_connection'
activerecord (4.2.4) lib/active_record/connection_adapters/abstract/connection_pool.rb:422:in `acquire_connection'
activerecord (4.2.4) lib/active_record/connection_adapters/abstract/connection_pool.rb:349:in `block in checkout'
/Users/mac_osx_username/.rvm/rubies/ruby-2.2.3/lib/ruby/2.2.0/monitor.rb:211:in `mon_synchronize'
activerecord (4.2.4) lib/active_record/connection_adapters/abstract/connection_pool.rb:348:in `checkout'
activerecord (4.2.4) lib/active_record/connection_adapters/abstract/connection_pool.rb:263:in `block in connection'
/Users/mac_osx_username/.rvm/rubies/ruby-2.2.3/lib/ruby/2.2.0/monitor.rb:211:in `mon_synchronize'
activerecord (4.2.4) lib/active_record/connection_adapters/abstract/connection_pool.rb:262:in `connection'
activerecord (4.2.4) lib/active_record/connection_adapters/abstract/connection_pool.rb:571:in `retrieve_connection'
activerecord (4.2.4) lib/active_record/connection_handling.rb:113:in `retrieve_connection'
activerecord (4.2.4) lib/active_record/connection_handling.rb:87:in `connection'
activerecord (4.2.4) lib/active_record/migration.rb:383:in `connection'
activerecord (4.2.4) lib/active_record/migration.rb:370:in `call'
actionpack (4.2.4) lib/action_dispatch/middleware/callbacks.rb:29:in `block in call'
activesupport (4.2.4) lib/active_support/callbacks.rb:88:in `__run_callbacks__'
activesupport (4.2.4) lib/active_support/callbacks.rb:778:in `_run_call_callbacks'
activesupport (4.2.4) lib/active_support/callbacks.rb:81:in `run_callbacks'
actionpack (4.2.4) lib/action_dispatch/middleware/callbacks.rb:27:in `call'
actionpack (4.2.4) lib/action_dispatch/middleware/reloader.rb:73:in `call'
actionpack (4.2.4) lib/action_dispatch/middleware/remote_ip.rb:78:in `call'
actionpack (4.2.4) lib/action_dispatch/middleware/debug_exceptions.rb:17:in `call'
web-console (2.2.1) lib/web_console/middleware.rb:39:in `call'
actionpack (4.2.4) lib/action_dispatch/middleware/show_exceptions.rb:30:in `call'
railties (4.2.4) lib/rails/rack/logger.rb:38:in `call_app'
railties (4.2.4) lib/rails/rack/logger.rb:20:in `block in call'
activesupport (4.2.4) lib/active_support/tagged_logging.rb:68:in `block in tagged'
activesupport (4.2.4) lib/active_support/tagged_logging.rb:26:in `tagged'
activesupport (4.2.4) lib/active_support/tagged_logging.rb:68:in `tagged'
railties (4.2.4) lib/rails/rack/logger.rb:20:in `call'
quiet_assets (1.1.0) lib/quiet_assets.rb:27:in `call_with_quiet_assets'
actionpack (4.2.4) lib/action_dispatch/middleware/request_id.rb:21:in `call'
rack (1.6.4) lib/rack/methodoverride.rb:22:in `call'
rack (1.6.4) lib/rack/runtime.rb:18:in `call'
activesupport (4.2.4) lib/active_support/cache/strategy/local_cache_middleware.rb:28:in `call'
rack (1.6.4) lib/rack/lock.rb:17:in `call'
actionpack (4.2.4) lib/action_dispatch/middleware/static.rb:116:in `call'
rack (1.6.4) lib/rack/sendfile.rb:113:in `call'
railties (4.2.4) lib/rails/engine.rb:518:in `call'
railties (4.2.4) lib/rails/application.rb:165:in `call'
rack (1.6.4) lib/rack/lock.rb:17:in `call'
rack (1.6.4) lib/rack/content_length.rb:15:in `call'
rack (1.6.4) lib/rack/handler/webrick.rb:88:in `service'
由于 database.yml 包括主机和端口，Rails 可能正在尝试连接到 TCP 套接字，而您通过 psql 和 pg 的连接（因为它们不指定主机或端口）正在使用 UNIX 套接字。 PostgreSQL 开箱即用地配置为 不 侦听 TCP 套接字，因此请查看 postgresql.conf 并确保它已取消注释 listen_addresses。如果没有，您可以尝试从 database.yml 中取出主机和端口，或者修改配置以启用 TCP 连接并重新启动 PostgreSQL。