Rails：致命-用户的对等身份验证失败（PG :: Error）

我正在Ubuntu 11.10和RubyMine上运行开发

这是我对database.yml的开发设置：RubyMine为我创建的

development:
  adapter: postgresql
  encoding: unicode
  database: mydb_development
  pool: 5
  username: myuser
  password:

当我尝试运行该应用程序时，出现以下错误，似乎我还没有创建“项目”用户，但是，如何在postgres中创建用户并为其授予数据库？如果这是问题所在，那么在Ubuntu中为此任务推荐使用什么工具？如果这不是问题，那么请提出建议。

Exiting
/home/sam/.rvm/gems/ruby-1.9.3-p0@project/gems/activerecord-3.2.3/lib/active_record/connection_adapters/postgresql_adapter.rb:1194:in `initialize': FATAL:  Peer authentication failed for user "project" (PG::Error)
    from /home/sam/.rvm/gems/ruby-1.9.3-p0@project/gems/activerecord-3.2.3/lib/active_record/connection_adapters/postgresql_adapter.rb:1194:in `new'
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    from /home/sam/.rvm/gems/ruby-1.9.3-p0@project/gems/activerecord-3.2.3/lib/active_record/connection_adapters/postgresql_adapter.rb:28:in `new'
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    from /home/sam/.rvm/gems/ruby-1.9.3-p0@project/gems/activerecord-3.2.3/lib/active_record/connection_adapters/abstract/connection_pool.rb:237:in `block (2 levels) in checkout'
    from /home/sam/.rvm/gems/ruby-1.9.3-p0@project/gems/activerecord-3.2.3/lib/active_record/connection_adapters/abstract/connection_pool.rb:232:in `loop'
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    from /home/sam/.rvm/gems/ruby-1.9.3-p0@project/gems/activerecord-3.2.3/lib/active_record/connection_adapters/abstract/connection_specification.rb:142:in `connection'
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Process finished with exit code 1

如果您在服务器上安装了postresql，则只需将host：localhost托管到database.yml，我通常将其放置在其显示pool：5的地方。否则，如果不是localhost，则肯定告诉该应用程序在哪里找到其数据库。

development:
  adapter: postgresql
  encoding: unicode
  database: kickrstack_development
  host: localhost
  pool: 5
  username: kickrstack
  password: secret

通过创建数据库并将所有权分配给应用程序的用户以建立连接，确保正确设置了用户凭据。要在postgresql 9中创建新用户，请运行：

sudo -u postgres psql

如果没有，请设置postgresql用户密码，这只是反斜杠密码。

postgres=# \password

创建一个新用户和密码以及用户的新数据库：

postgres=# create user "guy_on_stackoverflow" with password 'keepitonthedl';
postgres=# create database "dcaclab_development" owner "guy_on_stackoverflow"; 

在确认创建数据库，用户，密码并设置了这些特权之后，现在更新您的database.yml文件。不要忘记主机：localhost。

这是在Ubuntu 13.10 的开发环境中使Rails应用程序与postgres一起使用的最简单的方法。

1）在Gemfile中使用postgres YAML和'pg'gem创建rails应用程序：

$ rails new my_application -d postgresql

2）给它一些CRUD功能。如果您只是想看看postgres是否有效，请创建一个脚手架：

$ rails g scaffold cats name:string age:integer colour:string

3）从选项开始，rails 4.0.1将-d postgresql生成不包含主机参数的YAML。我发现我需要这个。编辑开发部分并创建以下参数：

encoding: UTF-8
host: localhost
database: my_application_development
username: thisismynewusername
password: thisismynewpassword 

请注意，该database参数用于尚未退出的数据库，并且username和password是不存在的角色的凭据。我们稍后将创建它们！

这是config/database.yml应该看起来的样子（copypasting：D中不要感到羞耻）：

development:
  adapter: postgresql
  pool: 5
  # these are our new parameters
  encoding: UTF-8
  database: my_application_development
  host: localhost
  username: thisismynewusername
  password: thisismynewpassword

test:
  # this won't work 
  adapter: postgresql
  encoding: unicode
  database: my_application_test
  pool: 5
  username: my_application
  password:

production:
  # this won't work 
  adapter: postgresql
  encoding: unicode
  database: my_application_production
  pool: 5
  username: my_application
  password:

4）使用以下命令启动postgres shell：

$ psql

4a）如果您当前的用户（如您的计算机用户）没有相应的管理postgres角色，则可能会收到此错误。

psql: FATAL:  role "your_username" does not exist

现在我只安装了一次postgres，所以在这里我可能错了，但是我认为postgres会自动创建一个管理角色，其凭据与安装postgres的用户相同。

4b）因此，这意味着您需要更改为安装postgres的用户才能使用psql命令并启动shell：

$ sudo su postgres

然后跑

$ psql

5）您将知道自己在postgres外壳中，因为您的终端如下所示：

$ psql
psql (9.1.10)
Type "help" for help.

postgres=# 

6）使用PostgreSQL的语法，让我们创建我们指定的用户config/database.yml的发展部分：

postgres=# CREATE ROLE thisismynewusername WITH LOGIN PASSWORD 'thisismynewpassword';

现在，这里有一些微妙之处，让我们来看一下。

• 该角色的用户名，thisismynewusername，没有周围有任何形式的报价
• 在WITH之后指定关键字LOGIN。如果不这样做，则仍将创建该角色，但它将无法登录数据库！
• 角色的密码thisismynewpassword必须用单引号引起来。不是双引号。
• 最后加一个半冒号;）

您应该在终端中看到以下内容：

postgres=#
CREATE ROLE
postgres=#

这意味着“角色已创建”，但postgres的警报似乎采用了git hub相同的命令式约定。

7）现在，仍然在postgres shell中，我们需要使用在YAML中设置的名称创建数据库。使我们在第6步中创建的用户成为所有者：

postgres=# CREATE DATABASE my_application_development OWNER thisismynewusername;

您会知道自己是否成功，因为您将获得输出：

CREATE DATABASE

8）退出postgres shell：

\q

9）现在是关键时刻：

$ RAILS_ENV=development rake db:migrate

如果得到这个：

==  CreateCats: migrating =================================================
-- create_table(:cats)
   -> 0.0028s
==  CreateCats: migrated (0.0028s) ========================================

恭喜，postgres与您的应用完美配合。

9a）在我的本地计算机上，我不断收到权限错误。我记不清了，但这是一个错误

Can't access the files. Change permissions to 666.

尽管我建议您仔细考虑在生产计算机上递归设置写特权的方法，但我还是在本地为整个应用程序提供了以下写特权：

9b）爬升一个目录级别：

$ cd ..

9c）将my_application目录及其所有内容的权限设置为666：

$ chmod -R 0666 my_application

9d）并再次运行迁移：

$ RAILS_ENV=development rake db:migrate

==  CreateCats: migrating =================================================
-- create_table(:cats)
   -> 0.0028s
==  CreateCats: migrated (0.0028s) ========================================

如果您搞砸了一些提示和技巧

在重新启动所有这些步骤之前，请尝试以下操作：

mynewusername用户没有权限对my_app_development数据库进行CRUD 吗？删除数据库，并以mynewusername作为所有者再次创建它：

1）启动postgres shell：

$ psql

2）删除my_app_development数据库。小心！删除意味着彻底删除！

postgres=# DROP DATABASE my_app_development;

3）重新创建另一个my_app_development，并将mynewusername设置为所有者：

postgres=# CREATE DATABASE my_application_development OWNER mynewusername;

4）退出shell：

postgres=# \q

该mynewusername用户不能登录到数据库？认为您在YAML中输入了错误的密码，还不太记得使用postgres shell输入的密码吗？只需使用YAML密码更改角色即可：

1）打开您的YAML，然后将密码复制到剪贴板：

 development:
      adapter: postgresql
      pool: 5
      # these are our new parameters
      encoding: UTF-8
      database: my_application_development
      host: localhost
      username: thisismynewusername
      password: musthavebeenverydrunkwheniwrotethis

2）启动postgres shell：

$ psql    

3）更新mynewusername密码。粘贴密码，并记住在密码两边加上单引号：

postgres=# ALTER ROLE mynewusername PASSWORD `musthavebeenverydrunkwheniwrotethis`;

4）退出shell：

postgres=# \q

试图通过数据库查看器（例如Dbeaver）连接到localhost，并且不知道您的postgres用户密码是什么？像这样更改它：

1）passwd以超级用户身份运行：

$ sudo passwd postgres

2）输入您的帐户密码sudo（与postgres无关）：

[sudo] password for starkers: myaccountpassword

3）创建postgres帐户的新密码：

Enter new UNIX password: databasesarefun
Retype new UNIX password: databasesarefun
passwd: password updated successfully

收到此错误消息？：

Run `$ bin/rake db:create db:migrate` to create your database
$ rake db:create db:migrate
PG::InsufficientPrivilege: ERROR:  permission denied to create database

4）您需要使您的用户能够创建数据库。从psql shell：

ALTER ROLE thisismynewusername WITH CREATEDB

对于永久解决方案：

问题出在你的pg_hba上。这行：

local   all             postgres                                peer

应该

local   all             postgres                                md5

然后在更改此文件后重新启动您的postgresql服务器。

如果您使用的是Linux，则命令为

sudo service postgresql restart

我在Ubuntu计算机上也遇到了同样的问题，因此我按照一些步骤删除了此错误。切换到postgres用户

$ sudo su - postgres

它将要求输入密码，默认情况下密码为 postgres

将用户切换到postgres后，打开psql控制台

$ psql

所以检查postgres的版本是否有多个可用版本

psql=# select VERSION();

PostgreSQL 9.1.13 on x86_64-unk....         # so version is 9.1

现在开放 postgres user

vim /etc/postgresql/9.1/main/pg_hba.conf

9.1 是版本返回形式的上命令

并替换

local   all             postgres                                peer

至

local   all             postgres                                md5

重新启动服务

sudo service postgresql restart

我也在博客上写了步骤

http://tarungarg402.blogspot.in/2014/10/set-up-postgresql-on-ubuntu.html

您可以转到/var/lib/pgsql/data/pg_hba.conf文件，并添加信任来代替Ident。

local   all all trust
host    all 127.0.0.1/32    trust

有关更多详细信息，请参阅此问题 。用户的身份验证失败

加host: localhost给我的魔力

development:
  adapter: postgresql
  database: database_name_here
  host: localhost
  username: user_name_here

如果Peer authentication failed for user (PG::Error)在运行单元测试时收到该错误消息（），请确保测试数据库存在。

在开发环境中工作时，我也遇到了同样的问题，问题是我host: localhost在config/database.yml文件中。

因此，我的应用程序无法连接到PostgreSQL数据库，只需取消注释即可解决该问题。

development:
  <<: *default
  database: database_name

  username: database_username 

  password: database_password

  host: localhost

就这样。

我希望这有帮助