如何使用 PostgreSQL 解决 Rails 中的错误“fe_sendauth：未提供密码”？答案

【问题标题】：How to resolve the error 'fe_sendauth: no password supplied' in Rails using PostgreSQL?如何使用 PostgreSQL 解决 Rails 中的错误“fe_sendauth：未提供密码”？
【发布时间】：2015-07-23 16:47:05
【问题描述】：

我尝试使用 postgresql 数据库创建我的 Rails 应用程序，但是当我启动 rails server 时，我收到了这个错误：

fe_sendauth：未提供密码

这是我的操作步骤：

$ sudo apt-get install postgresql postgresql-contrib
$ gem install pg
$ rails new timetracker --database=postgresql --skip-unit-test

我的database.yml 文件如下所示：

default: &default
  adapter: postgresql
  encoding: unicode
  pool: 5
  host: localhost
  username: postgres
  password:

development:
  <<: *default
  database: timetracker_development

test:
  <<: *default
  database: timetracker_test

production:
  <<: *default
  database: timetracker_production

这是我的pg_hba.conf 文件：

# Database administrative login by Unix domain socket
local   all             postgres                                peer

# TYPE  DATABASE        USER            ADDRESS                 METHOD

# "local" is for Unix domain socket connections only
local   all             all                                     peer
# IPv4 local connections:
host    all             all             127.0.0.1/32            md5
# IPv6 local connections:
host    all             all             ::1/128                 md5

# modified by me.
host    all             all             127.0.0.1/32            trust

host    all             all             127.0.0.1/32            trust

host    all             all             ::1/128                 trust

所以，当我执行rails server 时，我得到了错误，然后这就是我这样做的结果：

$ rails c
$ ActiveRecord::Base.connection.instance_variable_get(:@config)

2.1.5 :001 > ActiveRecord::Base.connection.instance_variable_get(:@config) PG::ConnectionBad: fe_sendauth: 未提供密码

来自 /home/denis/.rvm/gems/ruby-2.1.5/gems/activerecord-4.2.3/lib/active_record/connection_adapter/postgresql_adapter.rb:655:in initialize' from /home/denis/.rvm/gems/ruby-2.1.5/gems/activerecord-4.2.3/lib/active_record/connection_adapters/postgresql_adapter.rb:655:innew' 来自 /home/denis/.rvm/gems/ruby-2.1.5/gems/activerecord-4.2.3/lib/active_record/connection_adapter/postgresql_adapter.rb:655:in connect' from /home/denis/.rvm/gems/ruby-2.1.5/gems/activerecord-4.2.3/lib/active_record/connection_adapters/postgresql_adapter.rb:242:ininitialize' 来自 /home/denis/.rvm/gems/ruby-2.1.5/gems/activerecord-4.2.3/lib/active_record/connection_adapters/postgresql_adapter.rb:44:in new' from /home/denis/.rvm/gems/ruby-2.1.5/gems/activerecord-4.2.3/lib/active_record/connection_adapters/postgresql_adapter.rb:44:inpostgresql_connection' 来自 /home/denis/.rvm/gems/ruby-2.1.5/gems/activerecord-4.2.3/lib/active_record/connection_adapters/abstract/connection_pool.rb:438:in new_connection' from /home/denis/.rvm/gems/ruby-2.1.5/gems/activerecord-4.2.3/lib/active_record/connection_adapters/abstract/connection_pool.rb:448:incheckout_new_connection' 来自 /home/denis/.rvm/gems/ruby-2.1.5/gems/activerecord-4.2.3/lib/active_record/connection_adapters/abstract/connection_pool.rb:422:in acquire_connection' from /home/denis/.rvm/gems/ruby-2.1.5/gems/activerecord-4.2.3/lib/active_record/connection_adapters/abstract/connection_pool.rb:349:inblock in checkout' 来自 /home/denis/.rvm/rubies/ruby-2.1.5/lib/ruby/2.1.0/monitor.rb:211:in mon_synchronize' from /home/denis/.rvm/gems/ruby-2.1.5/gems/activerecord-4.2.3/lib/active_record/connection_adapters/abstract/connection_pool.rb:348:incheckout' 来自 /home/denis/.rvm/gems/ruby-2.1.5/gems/activerecord-4.2.3/lib/active_record/connection_adapters/abstract/connection_pool.rb:263:in block in connection' from /home/denis/.rvm/rubies/ruby-2.1.5/lib/ruby/2.1.0/monitor.rb:211:inmon_synchronize' 来自 /home/denis/.rvm/gems/ruby-2.1.5/gems/activerecord-4.2.3/lib/active_record/connection_adapters/abstract/connection_pool.rb:262:in connection' from /home/denis/.rvm/gems/ruby-2.1.5/gems/activerecord-4.2.3/lib/active_record/connection_adapters/abstract/connection_pool.rb:571:inretrieve_connection' ... 4 个级别... 从 /home/denis/.rvm/gems/ruby-2.1.5/gems/railties-4.2.3/lib/rails/commands/console.rb:9:in start' from /home/denis/.rvm/gems/ruby-2.1.5/gems/railties-4.2.3/lib/rails/commands/commands_tasks.rb:68:inconsole' 来自 /home/denis/.rvm/gems/ruby-2.1.5/gems/railties-4.2.3/lib/rails/commands/commands_tasks.rb:39:in run_command!' from /home/denis/.rvm/gems/ruby-2.1.5/gems/railties-4.2.3/lib/rails/commands.rb:17:in' 来自 /home/denis/.rvm/gems/ruby-2.1.5/gems/activesupport-4.2.3/lib/active_support/dependencies.rb:274:in require' from /home/denis/.rvm/gems/ruby-2.1.5/gems/activesupport-4.2.3/lib/active_support/dependencies.rb:274:inblock in require' 来自 /home/denis/.rvm/gems/ruby-2.1.5/gems/activesupport-4.2.3/lib/active_support/dependencies.rb:240:in load_dependency' from /home/denis/.rvm/gems/ruby-2.1.5/gems/activesupport-4.2.3/lib/active_support/dependencies.rb:274:inrequire' 来自 /home/denis/WEB/Rails/ timetracker/bin/rails:8:in <top (required)>' from /home/denis/.rvm/gems/ruby-2.1.5/gems/activesupport-4.2.3/lib/active_support/dependencies.rb:268:inload' 来自 /home/denis/.rvm/gems/ruby-2.1.5/gems/activesupport-4.2.3/lib/active_support/dependencies.rb:268:in block in load' from /home/denis/.rvm/gems/ruby-2.1.5/gems/activesupport-4.2.3/lib/active_support/dependencies.rb:240:inload_dependency' 来自 /home/denis/.rvm/gems/ruby-2.1.5/gems/activesupport-4.2.3/lib/active_support/dependencies.rb:268:in load' from /home/denis/.rvm/rubies/ruby-2.1.5/lib/ruby/site_ruby/2.1.0/rubygems/core_ext/kernel_require.rb:54:inrequire' 来自 /home/denis/.rvm/rubies/ruby-2.1.5/lib/ruby/site_ruby/2.1.0/rubygems/core_ext/kernel_require.rb:54:in require' from -e:1:in'2.1.5 :002 >

我是第一次使用 postgresql，我想我只是做错了什么。

你能帮我解决这个问题吗？

【问题讨论】：

将您的修改移至pg_hba.conf，高于预先提供的修改。你还有一个重复的条目。
@ColonelThirtyTwo 不幸的是，这并没有改变任何东西。仍然遇到同样的错误...
也执行sudo service postgresql reload 或重新启动以加载更改
@ColonelThirtyTwo，谢谢，我想它有效，但我开始收到新错误：FATAL: database "timetracker_development" does not exist。我真的应该手动创建所有数据库吗（我认为 rails 会为我这样做）？
可能。不熟悉 Rails，但我见过的大多数 ORM 只创建表等，而不是实际的数据库。

标签： postgresql ruby-on-rails-4 ubuntu-14.04 postgresql-9.3

【解决方案1】：

PostgreSQL 按照指定的顺序匹配pg_hba.conf 条目，因此它使用预先指定的host all all 127.0.0.1/32 md5 条目而不是您指定的trust 条目进行身份验证。

将您的自定义 trust 条目移到预先指定的条目之上（并可选择注释掉旧条目），然后通过运行 sudo service postgresql reload（在 Ubuntu 上）或重新启动来重新加载您的配置。

【讨论】：

【解决方案2】：

我对这个问题的解决方案是从default: 组中删除host: localhost。

【讨论】：

这个工作的原因是没有定义host Unix 套接字被使用。在身份验证期间，它将匹配pg_hba.conf 中的peer 规则，因此不需要密码（您的用户名whoami 必须与数据库中的角色匹配）。

【解决方案3】：

我不知道为什么，但对我来说，这条线并没有解决问题

host    mydb       myuser         127.0.0.1/32            trust

虽然这个：

host    mydb       myuser         localhost               trust

【讨论】：