当我在生产中运行 heroku run rake db:migrate 时出现此错误答案

【问题标题】：I get this error when i run heroku run rake db:migrate in production当我在生产中运行 heroku run rake db:migrate 时出现此错误
【发布时间】：2016-11-18 06:11:26
【问题描述】：

当我在生产中运行 heroku run rake db:migrate 时出现此错误。弃用警告：config.serve_static_files 已弃用，将在 Rails 5.1 中删除。请改用config.public_file_server.enabled = true。（从 /app/config/environments/production.rb:25 的块中调用）

我在 stackoverflow 上尝试了一些解决方案，但我无法解决问题。

这是我的 production.rb 文件

Rails.application.configure do
  # Settings specified here will take precedence over those in config/application.rb.

  # Code is not reloaded between requests.
  config.cache_classes = true

  # Eager load code on boot. This eager loads most of Rails and
  # your application in memory, allowing both threaded web servers
  # and those relying on copy on write to perform better.
  # Rake tasks automatically ignore this option for performance.
  config.eager_load = true

  # Full error reports are disabled and caching is turned on.
  config.consider_all_requests_local       = false
  config.action_controller.perform_caching = true

  # Enable Rack::Cache to put a simple HTTP cache in front of your application
  # Add `rack-cache` to your Gemfile before enabling this.
  # For large-scale production use, consider using a caching reverse proxy like
  # NGINX, varnish or squid.
  # config.action_dispatch.rack_cache = true

  # Disable serving static files from the `/public` folder by default since
  # Apache or NGINX already handles this.
  config.serve_static_files = ENV['RAILS_SERVE_STATIC_FILES'].present?

  # Compress JavaScripts and CSS.
  config.assets.js_compressor = :uglifier
  # config.assets.css_compressor = :sass

  # Do not fallback to assets pipeline if a precompiled asset is missed.
  config.assets.compile = true

  # Asset digests allow you to set far-future HTTP expiration dates on all assets,
  # yet still be able to expire them through the digest params.
  config.assets.digest = true

  # `config.assets.precompile` and `config.assets.version` have moved to config/initializers/assets.rb

  # Specifies the header that your server uses for sending files.
  # config.action_dispatch.x_sendfile_header = 'X-Sendfile' # for Apache
  # config.action_dispatch.x_sendfile_header = 'X-Accel-Redirect' # for NGINX

  # Force all access to the app over SSL, use Strict-Transport-Security, and use secure cookies.
   config.force_ssl = true

  # Use the lowest log level to ensure availability of diagnostic information
  # when problems arise.
  config.log_level = :debug

  # Prepend all log lines with the following tags.
  # config.log_tags = [ :subdomain, :uuid ]

  # Use a different logger for distributed setups.
  # config.logger = ActiveSupport::TaggedLogging.new(SyslogLogger.new)

  # Use a different cache store in production.
  # config.cache_store = :mem_cache_store

  # Enable serving of images, stylesheets, and JavaScripts from an asset server.
  # config.action_controller.asset_host = 'http://assets.example.com'

  # Ignore bad email addresses and do not raise email delivery errors.
  # Set this to true and configure the email server for immediate delivery to raise delivery errors.
  # config.action_mailer.raise_delivery_errors = false

  # Enable locale fallbacks for I18n (makes lookups for any locale fall back to
  # the I18n.default_locale when a translation cannot be found).
  config.i18n.fallbacks = true

  # Send deprecation notices to registered listeners.
  config.active_support.deprecation = :notify

  # Use default logging formatter so that PID and timestamp are not suppressed.
  config.log_formatter = ::Logger::Formatter.new

  # Do not dump schema after migrations.
  config.active_record.dump_schema_after_migration = false
end

【问题讨论】：

这是一个弃用警告（不是错误）。这很好修复，但如果继续在固定版本上运行所有内容，不会破坏您的应用程序。

标签： ruby-on-rails ruby heroku

【解决方案1】：

是的，用这个替换不推荐使用的代码：

 config.public_file_server.enabled = ENV['RAILS_SERVE_STATIC_FILES'].present?

来源：https://devcenter.heroku.com/articles/getting-started-with-rails5#heroku-gems

【讨论】：

【解决方案2】：

首先它不是错误而是警告并从您的文件 config.serve_static_files 中删除这一行，而不是使用 config.public_file_server.enabled = true

【讨论】：

【解决方案3】：

可以换吗

config.serve_static_files = ENV['RAILS_SERVE_STATIC_FILES'].present?

与

config.public_file_server.enabled = ENV['RAILS_SERVE_STATIC_FILES'].present?

看看这是否有效？

【讨论】：

【解决方案4】：

警告本身说：

弃用警告：config.serve_static_files 已弃用并将在 Rails 5.1 中删除。请使用 config.public_file_server.enabled = true 相反。（从 /app/config/environments/production.rb:25 的块中调用）

在 production.rb 文件的第 25 行：

你需要更换：

  config.serve_static_files = ENV['RAILS_SERVE_STATIC_FILES'].present?

与

config.public_file_server.enabled = true # ENV['RAILS_SERVE_STATIC_FILES'].present?

有关Rails 5 serve_static_assets deprecation warning

的更多信息

【讨论】：

【解决方案5】：

如果您已更新配置选项以使用 public_file_server 并且仍然看到弃用警告，请尝试按照 Heroku 的建议从您的 Gemfile 中删除 gem 'rails_12factor'。

https://devcenter.heroku.com/articles/getting-started-with-rails5#heroku-gems

【讨论】：