rails database.yml不接受ERB

Question

在我的database.yml中,我有:

staging:
  adapter: <%= ENV['DATABASE_ADAPTER'] %>
  encoding: <%= ENV['DATABASE_ENCODING'] %>
  database: <%= ENV['DATABASE'] %>
  host: <%= ENV['DATABASE_HOST'] %>
  port: <%= ENV['DATABASE_PORT'].to_i %>
  pool: <%= ENV['DATABASE_POOL'].to_i %>
  username: <%= ENV['DATABASE_USERNAME'] %>
  password: <%= ENV['DATABASE_PASSWORD'] %>

但是,在实际启动puma时它不会读取ERB部分:

/usr/local/lib/ruby/gems/2.1.0/gems/activesupport-4.2.1/lib/active_support/dependencies.rb:274:in 
`require': Could not load 'active_record/connection_adapters/<%= ENV['DATABASE_ADAPTER'] %>_adapter'. 
Make sure that the adapter in config/database.yml is valid. If you use an adapter other than 'mysql', 'mysql2', 'postgresql' or 'sqlite3'
add the necessary adapter gem to the Gemfile. (LoadError)

这没有任何意义,因为在Rails代码中加载数据库配置:

  def database_configuration
    yaml = Pathname.new(paths["config/database"].existent.first || "")

    config = if yaml.exist?
      require "yaml"
      require "erb"
      YAML.load(ERB.new(yaml.read).result) || {}
    elsif ENV['DATABASE_URL']
      # Value from ENV['DATABASE_URL'] is set to default database connection
      # by Active Record.
      {}
    else
      raise "Could not load database configuration. No such file - #{yaml}"
    end

    config
  rescue Psych::SyntaxError => e
    raise "YAML syntax error occurred while parsing #{paths["config/database"].first}. " \
          "Please note that YAML must be consistently indented using spaces. Tabs are not allowed. " \
          "Error: #{e.message}"
  rescue => e
    raise e, "Cannot load `Rails.application.database_configuration`:\n#{e.message}", e.backtrace
  end

(取自Rails 4.2稳定代码,我正在运行4.2.1)

我完全不知道为什么这不起作用,任何想法？

Answer 1

我刚刚经历过同样的事情,并且发现了你的帖子.我一直在关注一个教程,让我创建一个包含以下代码的puma.conf文件:

ActiveRecord::Base.establish_connection( YAML.load_file( "#{app_dir}/config/database.yml" )[rails_env])

我修改为以下,一切按预期工作:

require 'erb'
ActiveRecord::Base.establish_connection( YAML.load( ERB.new( File.read( "#{app_dir}/config/database.yml" )).result)[rails_env])