```ruby
module ElasticRecord
  class Railtie < Rails::Railtie
    initializer 'elastic_record.require_log_subscriber' do
      require 'elastic_record/log_subscriber'
    end

    initializer "elastic_record.config" do |app|
      pathname = Rails.root.join('config', 'elasticsearch.yml')
      if pathname.exist?
        config = YAML.load(pathname.read)

        if config = config[Rails.env]
          ElasticRecord::Config.settings = config
        else
          raise "Missing environment #{Rails.env} in superstore.yml"
        end
      end
    end

    rake_tasks do
      load "elastic_record/tasks/index.rake"
    end

    # Expose database runtime to controller for logging.
    initializer "elastic_record.log_runtime" do |app|
      require "elastic_record/railties/controller_runtime"
      ActiveSupport.on_load(:action_controller) do
        include ElasticRecord::Railties::ControllerRuntime
      end
    end
  end
end
```

Use erb to read in config
user
```ruby
module ElasticRecord
  class Railtie < Rails::Railtie
    initializer 'elastic_record.require_log_subscriber' do
      require 'elastic_record/log_subscriber'
    end

    initializer "elastic_record.config" do |app|
      pathname = Rails.root.join('config', 'elasticsearch.yml')
      if pathname.exist?
        config = ERB.new(pathname.read).result
        config = YAML.load(config)

        if config = config[Rails.env]
          ElasticRecord::Config.settings = config
        else
          raise "Missing environment #{Rails.env} in superstore.yml"
        end
      end
    end

    rake_tasks do
      load "elastic_record/tasks/index.rake"
    end

    # Expose database runtime to controller for logging.
    initializer "elastic_record.log_runtime" do |app|
      require "elastic_record/railties/controller_runtime"
      ActiveSupport.on_load(:action_controller) do
        include ElasticRecord::Railties::ControllerRuntime
      end
    end
  end
end
```
assistant