致命：角色“root”不存在

Question

我尝试使用 postgresql 数据库创建 rails 应用程序，但是当我创建数据库时 rake db:migrate bash 显示错误

FATAL:  role "my" does not exist

如何解决？

对不起我的英语不好

UPD

my@my-P5K-SE ~/ror/timonin $ rake db:create
FATAL:  role "my" does not exist
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.4/lib/active_record/connection_adapters/postgresql_adapter.rb:898:in `rescue in connect'
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.4/lib/active_record/connection_adapters/postgresql_adapter.rb:888:in `connect'
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.4/lib/active_record/connection_adapters/postgresql_adapter.rb:568:in `initialize'
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.4/lib/active_record/connection_adapters/postgresql_adapter.rb:41:in `new'
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.4/lib/active_record/connection_adapters/postgresql_adapter.rb:41:in `postgresql_connection'
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.4/lib/active_record/connection_adapters/abstract/connection_pool.rb:435:in `new_connection'
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.4/lib/active_record/connection_adapters/abstract/connection_pool.rb:445:in `checkout_new_connection'
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.4/lib/active_record/connection_adapters/abstract/connection_pool.rb:416:in `acquire_connection'
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.4/lib/active_record/connection_adapters/abstract/connection_pool.rb:351:in `block in checkout'
/usr/local/rvm/rubies/ruby-2.1.3/lib/ruby/2.1.0/monitor.rb:211:in `mon_synchronize'
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.4/lib/active_record/connection_adapters/abstract/connection_pool.rb:350:in `checkout'
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.4/lib/active_record/connection_adapters/abstract/connection_pool.rb:265:in `block in connection'
/usr/local/rvm/rubies/ruby-2.1.3/lib/ruby/2.1.0/monitor.rb:211:in `mon_synchronize'
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.4/lib/active_record/connection_adapters/abstract/connection_pool.rb:264:in `connection'
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.4/lib/active_record/connection_adapters/abstract/connection_pool.rb:541:in `retrieve_connection'
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.4/lib/active_record/connection_handling.rb:113:in `retrieve_connection'
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.4/lib/active_record/connection_handling.rb:87:in `connection'
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.4/lib/active_record/tasks/postgresql_database_tasks.rb:8:in `connection'
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.4/lib/active_record/tasks/postgresql_database_tasks.rb:17:in `create'
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.4/lib/active_record/tasks/database_tasks.rb:88:in `create'
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.4/lib/active_record/tasks/database_tasks.rb:102:in `block in create_current'
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.4/lib/active_record/tasks/database_tasks.rb:209:in `block in each_current_configuration'
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.4/lib/active_record/tasks/database_tasks.rb:208:in `each'
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.4/lib/active_record/tasks/database_tasks.rb:208:in `each_current_configuration'
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.4/lib/active_record/tasks/database_tasks.rb:101:in `create_current'
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.4/lib/active_record/railties/databases.rake:17:in `block (2 levels) in <top (required)>'
/usr/local/rvm/gems/ruby-2.1.3/gems/rake-10.3.2/lib/rake/task.rb:240:in `call'
/usr/local/rvm/gems/ruby-2.1.3/gems/rake-10.3.2/lib/rake/task.rb:240:in `block in execute'
/usr/local/rvm/gems/ruby-2.1.3/gems/rake-10.3.2/lib/rake/task.rb:235:in `each'
/usr/local/rvm/gems/ruby-2.1.3/gems/rake-10.3.2/lib/rake/task.rb:235:in `execute'
/usr/local/rvm/gems/ruby-2.1.3/gems/rake-10.3.2/lib/rake/task.rb:179:in `block in invoke_with_call_chain'
/usr/local/rvm/rubies/ruby-2.1.3/lib/ruby/2.1.0/monitor.rb:211:in `mon_synchronize'
/usr/local/rvm/gems/ruby-2.1.3/gems/rake-10.3.2/lib/rake/task.rb:172:in `invoke_with_call_chain'
/usr/local/rvm/gems/ruby-2.1.3/gems/rake-10.3.2/lib/rake/task.rb:165:in `invoke'
/usr/local/rvm/gems/ruby-2.1.3/gems/rake-10.3.2/lib/rake/application.rb:150:in `invoke_task'
/usr/local/rvm/gems/ruby-2.1.3/gems/rake-10.3.2/lib/rake/application.rb:106:in `block (2 levels) in top_level'
/usr/local/rvm/gems/ruby-2.1.3/gems/rake-10.3.2/lib/rake/application.rb:106:in `each'
/usr/local/rvm/gems/ruby-2.1.3/gems/rake-10.3.2/lib/rake/application.rb:106:in `block in top_level'
/usr/local/rvm/gems/ruby-2.1.3/gems/rake-10.3.2/lib/rake/application.rb:115:in `run_with_threads'
/usr/local/rvm/gems/ruby-2.1.3/gems/rake-10.3.2/lib/rake/application.rb:100:in `top_level'
/usr/local/rvm/gems/ruby-2.1.3/gems/rake-10.3.2/lib/rake/application.rb:78:in `block in run'
/usr/local/rvm/gems/ruby-2.1.3/gems/rake-10.3.2/lib/rake/application.rb:176:in `standard_exception_handling'
/usr/local/rvm/gems/ruby-2.1.3/gems/rake-10.3.2/lib/rake/application.rb:75:in `run'
/usr/local/rvm/gems/ruby-2.1.3/gems/rake-10.3.2/bin/rake:33:in `<top (required)>'
/usr/local/rvm/gems/ruby-2.1.3/bin/rake:23:in `load'
/usr/local/rvm/gems/ruby-2.1.3/bin/rake:23:in `<main>'
/usr/local/rvm/gems/ruby-2.1.3/bin/ruby_executable_hooks:15:in `eval'
/usr/local/rvm/gems/ruby-2.1.3/bin/ruby_executable_hooks:15:in `<main>'
Couldn't create database for {"adapter"=>"postgresql", "encoding"=>"unicode", "pool"=>5, "database"=>"timonin_development"}
FATAL:  role "my" does not exist
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.4/lib/active_record/connection_adapters/postgresql_adapter.rb:898:in `rescue in connect'
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.4/lib/active_record/connection_adapters/postgresql_adapter.rb:888:in `connect'
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.4/lib/active_record/connection_adapters/postgresql_adapter.rb:568:in `initialize'
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.4/lib/active_record/connection_adapters/postgresql_adapter.rb:41:in `new'
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.4/lib/active_record/connection_adapters/postgresql_adapter.rb:41:in `postgresql_connection'
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.4/lib/active_record/connection_adapters/abstract/connection_pool.rb:435:in `new_connection'
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.4/lib/active_record/connection_adapters/abstract/connection_pool.rb:445:in `checkout_new_connection'
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.4/lib/active_record/connection_adapters/abstract/connection_pool.rb:416:in `acquire_connection'
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.4/lib/active_record/connection_adapters/abstract/connection_pool.rb:351:in `block in checkout'
/usr/local/rvm/rubies/ruby-2.1.3/lib/ruby/2.1.0/monitor.rb:211:in `mon_synchronize'
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.4/lib/active_record/connection_adapters/abstract/connection_pool.rb:350:in `checkout'
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.4/lib/active_record/connection_adapters/abstract/connection_pool.rb:265:in `block in connection'
/usr/local/rvm/rubies/ruby-2.1.3/lib/ruby/2.1.0/monitor.rb:211:in `mon_synchronize'
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.4/lib/active_record/connection_adapters/abstract/connection_pool.rb:264:in `connection'
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.4/lib/active_record/connection_adapters/abstract/connection_pool.rb:541:in `retrieve_connection'
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.4/lib/active_record/connection_handling.rb:113:in `retrieve_connection'
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.4/lib/active_record/connection_handling.rb:87:in `connection'
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.4/lib/active_record/tasks/postgresql_database_tasks.rb:8:in `connection'
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.4/lib/active_record/tasks/postgresql_database_tasks.rb:17:in `create'
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.4/lib/active_record/tasks/database_tasks.rb:88:in `create'
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.4/lib/active_record/tasks/database_tasks.rb:102:in `block in create_current'
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.4/lib/active_record/tasks/database_tasks.rb:209:in `block in each_current_configuration'
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.4/lib/active_record/tasks/database_tasks.rb:208:in `each'
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.4/lib/active_record/tasks/database_tasks.rb:208:in `each_current_configuration'
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.4/lib/active_record/tasks/database_tasks.rb:101:in `create_current'
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.4/lib/active_record/railties/databases.rake:17:in `block (2 levels) in <top (required)>'
/usr/local/rvm/gems/ruby-2.1.3/gems/rake-10.3.2/lib/rake/task.rb:240:in `call'
/usr/local/rvm/gems/ruby-2.1.3/gems/rake-10.3.2/lib/rake/task.rb:240:in `block in execute'
/usr/local/rvm/gems/ruby-2.1.3/gems/rake-10.3.2/lib/rake/task.rb:235:in `each'
/usr/local/rvm/gems/ruby-2.1.3/gems/rake-10.3.2/lib/rake/task.rb:235:in `execute'
/usr/local/rvm/gems/ruby-2.1.3/gems/rake-10.3.2/lib/rake/task.rb:179:in `block in invoke_with_call_chain'
/usr/local/rvm/rubies/ruby-2.1.3/lib/ruby/2.1.0/monitor.rb:211:in `mon_synchronize'
/usr/local/rvm/gems/ruby-2.1.3/gems/rake-10.3.2/lib/rake/task.rb:172:in `invoke_with_call_chain'
/usr/local/rvm/gems/ruby-2.1.3/gems/rake-10.3.2/lib/rake/task.rb:165:in `invoke'
/usr/local/rvm/gems/ruby-2.1.3/gems/rake-10.3.2/lib/rake/application.rb:150:in `invoke_task'
/usr/local/rvm/gems/ruby-2.1.3/gems/rake-10.3.2/lib/rake/application.rb:106:in `block (2 levels) in top_level'
/usr/local/rvm/gems/ruby-2.1.3/gems/rake-10.3.2/lib/rake/application.rb:106:in `each'
/usr/local/rvm/gems/ruby-2.1.3/gems/rake-10.3.2/lib/rake/application.rb:106:in `block in top_level'
/usr/local/rvm/gems/ruby-2.1.3/gems/rake-10.3.2/lib/rake/application.rb:115:in `run_with_threads'
/usr/local/rvm/gems/ruby-2.1.3/gems/rake-10.3.2/lib/rake/application.rb:100:in `top_level'
/usr/local/rvm/gems/ruby-2.1.3/gems/rake-10.3.2/lib/rake/application.rb:78:in `block in run'
/usr/local/rvm/gems/ruby-2.1.3/gems/rake-10.3.2/lib/rake/application.rb:176:in `standard_exception_handling'
/usr/local/rvm/gems/ruby-2.1.3/gems/rake-10.3.2/lib/rake/application.rb:75:in `run'
/usr/local/rvm/gems/ruby-2.1.3/gems/rake-10.3.2/bin/rake:33:in `<top (required)>'
/usr/local/rvm/gems/ruby-2.1.3/bin/rake:23:in `load'
/usr/local/rvm/gems/ruby-2.1.3/bin/rake:23:in `<main>'
/usr/local/rvm/gems/ruby-2.1.3/bin/ruby_executable_hooks:15:in `eval'
/usr/local/rvm/gems/ruby-2.1.3/bin/ruby_executable_hooks:15:in `<main>'
Couldn't create database for {"adapter"=>"postgresql", "encoding"=>"unicode", "pool"=>5, "database"=>"timonin_test"}

数据库.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'
#
default: &default
  adapter: postgresql
  encoding: unicode
  # For details on connection pooling, see rails configuration guide
  # http://guides.rubyonrails.org/configuring.html#database-pooling
  pool: 5

development:
  <<: *default
  database: timonin_development

  # The specified database role being used to connect to postgres.
  # To create additional roles in postgres see `$ createuser --help`.
  # When left blank, postgres will use the default role. This is
  # the same name as the operating system user that initialized the database.
  #username: timonin

  # The password associated with the postgres role (username).
  #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:
  <<: *default
  database: timonin_test

# As with config/secrets.yml, you never want to store sensitive information,
# like your database password, in your source code. If your source code is
# ever seen by anyone, they now have access to your database.
#
# Instead, provide the password as a unix environment variable when you boot
# the app. Read http://guides.rubyonrails.org/configuring.html#configuring-a-database
# for a full rundown on how to provide these environment variables in a
# production deployment.
#
# On Heroku and other platform providers, you may have a full connection URL
# available as an environment variable. For example:
#
#   DATABASE_URL="postgres://myuser:mypass@localhost/somedatabase"
#
# You can use this database configuration with:
#
#   production:
#     url: <%= ENV['DATABASE_URL'] %>
#
production:
  <<: *default
  database: timonin_production
  username: timonin
  password: <%= ENV['TIMONIN_DATABASE_PASSWORD'] %>

Answer 1

您可以使用显式（my，即操作系统用户名）或隐式（timonin，即database.yml 中的角色）登录连接到 Postgres 服务器。

我看到您的database.yml 有用户名声明，但仅适用于生产环境。默认情况下，在不指定 Rails 环境的情况下运行 rake 测试将针对 development 环境运行它们。这就是为什么你有像FATAL: role "my" does not exist 这样的错误。

因此，根据您的需要，您必须将这些语句添加到所有数据库的定义中（test 和 development）：

  username: timonin
  password: <%= ENV['TIMONIN_DATABASE_PASSWORD'] %>

之后，您的 Rails 应用程序将以timonin 用户身份连接。

完整清单如下：

• 创建角色

这是 PostgreSQL 的 SQL：

CREATE ROLE timonin LOGIN PASSWORD 'Pas$_sword'
  NOINHERIT CREATEDB
   VALID UNTIL 'infinity';
COMMENT ON ROLE timonin
  IS 'Timonin database role for Rails app';

• 取消注释或添加语句 username: timonin 和 password: <%= ENV['TIMONIN_DATABASE_PASSWORD'] %> 到您的 database.yml 文件中
• 运行带有TIMONIN_DATABASE_PASSWORD变量的所有操作：

这里是改过的rake命令：

rake db:create TIMONIN_DATABASE_PASSWORD='Pas$_sword'

或：

rake db:create TIMONIN_DATABASE_PASSWORD='Pas$_sword' RAILS_ENV=test

用于测试环境。

Answer 2

我在使用 Ubuntu 14.04 LTS 安装 Ruby on Rails 时遇到了同样的问题。问题是我没有为我的 postgres 数据库创建一个用户，所以我做了以下操作并且它有效。

#1 以默认用户身份登录
$sudo su postgres

#2 登录 postgres 交互终端
psql

或者，您可以按如下方式组合第 1 步和第 2 步：
$sudo su postgres psql

#3 在 postgres 交互式终端中查看角色列表
postgres=#\du

#4 在 postgres 数据库中创建角色
postgres=# CREATE user with password '';

#5 让刚刚创建的用户成为超级用户
postgres=# 用超级用户改变用户；

#6 从 postgres 控制台退出
postgres=# \q