Question

# PostgreSQL. Versions 9.1 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: <%= ENV.fetch("RAILS_MAX_THREADS") { 5 } %>

development:
  <<: *default
  database: shoutr_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: shoutr

  # 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: shoutr_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: shoutr_production
  username: shoutr
  password: <%= ENV['SHOUTR_DATABASE_PASSWORD'] %>

正如您在config/database.yml文件中看到的那样，未定义开发和生产环境的密码，这些用户也未在PostgreSQL中创建，但是我仍然可以推送到Heroku，Heroku仍然可以提供应用程序利用的PostgreSQL生产环境数据库。

我正在尝试学习有关Rails开发的红宝石，以及此tutorial和从3:50开始，作者完成了bundle install，并立即完成了db:create，这暗示着他可以在开发环境中连接到PostgreSQL，而无需提供用户，也无需为开发环境更改config/database.yml中的值，如果我执行相同的操作会导致错误，那么可以通过在PostgreSQL中创建用户并更改yml文件中的凭据来解决该问题，但是我偶然发现的每个教程都不会显示用户的创建：

/home/webmaster/gems/gems/activesupport-5.2.2/lib/active_support/dependencies.rb:291:in `require'
bin/rails:4:in `<main>'

Caused by:
PG::InsufficientPrivilege: ERROR:  permission denied to create database

Answer 1

有两种主要的访问本地Postgresql数据库的方法。一种是在database.yml文件中使用特定的用户名/密码组合。另一种是设置本地postgres以信任您的用户身份。

对于后一种情况，您需要编辑pg_hba.conf文件，使其具有trust行（允许任何人连接，只需传递用户名）或peer或ident （取决于连接-套接字还是TCP-仅允许与连接用户同名的postgres角色，在您的情况下，可能是webmaster）

例如：

# Allow any user on the local system to connect to any database with
# any database user name using Unix-domain sockets (the default for local
# connections).
#
# TYPE  DATABASE        USER            ADDRESS                 METHOD
local   all             all                                     trust

# The same using local loopback TCP/IP connections.
#
# TYPE  DATABASE        USER            ADDRESS                 METHOD
host    all             all             127.0.0.1/32            trust

您可以在此处找到更多示例： https://www.postgresql.org/docs/devel/auth-pg-hba-conf.html

警告请勿在生产服务器上使用此配置！

即使未在database.yml中明确定义，Rails PostgreSQL如何在教程和Heroku中自动创建用户访问权限

1 个答案: