Rails - 使用 image_tag 时资产管道中不存在资产答案

【问题标题】：Rails - Asset is not present in asset pipeline when using image_tagRails - 使用 image_tag 时资产管道中不存在资产
【发布时间】：2018-09-01 13:52:38
【问题描述】：

目标：在生产环境中使用带有静态图像的 Rails 应用程序

步骤：

我将 Rails 应用转为生产环境。
使用RAILS_ENV=production rails assets:precompile 预编译资产
将RAILS_SERVE_STATIC_FILES环境变量设置为true以启用公共文件服务器（在production.rb - config.public_file_server.enabled = ENV['RAILS_SERVE_STATIC_FILES'].present?
已将行 config.serve_static_assets = true 添加到 /config/application.rb

通过这个设置，我已经启动了服务器。

我在/app/assets/images/ 中有一些静态图像，带有指纹文件名的预编译版本现在在/public/assets 中。例子：

aussen-d2fb0029a12281121a1752c599e715a8e2b3db17f1e8e18248a79a7b1ca63b91.jpg
hintergrund-ca80e1ae5a697c86898f3a7e107694a76dc12e54320b8ac80c58eecbffe0414a.png

到目前为止一切都很好。

当我在application.css.erb 中使用background-image: url(<%= asset_path('hintergrund') %>); 时，它成功地从/public/assets 加载预编译的背景图像。

问题：我无法在视图中使用我的 image_tags 访问预编译的图像！示例：

<%= image_tag("aussen") %>

错误日志：

I, [2018-03-23T00:46:29.133381 #9289]  INFO -- : [f36ff000-6261-4c2c-bfcc-4a2f80cae682] Started GET "/" for 46.142.136.81 at 2018-03-23 00:46:29 +0100
I, [2018-03-23T00:46:29.134466 #9289]  INFO -- : [f36ff000-6261-4c2c-bfcc-4a2f80cae682] Processing by HomeController#index as HTML
I, [2018-03-23T00:46:29.136604 #9289]  INFO -- : [f36ff000-6261-4c2c-bfcc-4a2f80cae682]   Rendering home/index.html.erb within layouts/application
I, [2018-03-23T00:46:29.138267 #9289]  INFO -- : [f36ff000-6261-4c2c-bfcc-4a2f80cae682]   Rendered home/index.html.erb within layouts/application (1.5ms)
I, [2018-03-23T00:46:29.138482 #9289]  INFO -- : [f36ff000-6261-4c2c-bfcc-4a2f80cae682] Completed 500 Internal Server Error in 4ms
F, [2018-03-23T00:46:29.139546 #9289] FATAL -- : [f36ff000-6261-4c2c-bfcc-4a2f80cae682]
F, [2018-03-23T00:46:29.139635 #9289] FATAL -- : [f36ff000-6261-4c2c-bfcc-4a2f80cae682] ActionView::Template::Error (The asset "aussen" is not present in the asset pipeline.):
F, [2018-03-23T00:46:29.139798 #9289] FATAL -- : [f36ff000-6261-4c2c-bfcc-4a2f80cae682]     1: <%= image_tag("aussen", id: "home-img", alt: "Aussenansicht von Simson-Seelig") %>
[f36ff000-6261-4c2c-bfcc-4a2f80cae682]     2: <div id="home" class="content">
[f36ff000-6261-4c2c-bfcc-4a2f80cae682]     3:   <p>Alles für Simson von Simson-Seelig.</p>
[f36ff000-6261-4c2c-bfcc-4a2f80cae682]     4:   <p>Für die legendären Schwalben und alle anderen SIMSON-Modelle bieten wir Ersatzteile und Service. </p>
F, [2018-03-23T00:46:29.139867 #9289] FATAL -- : [f36ff000-6261-4c2c-bfcc-4a2f80cae682]
F, [2018-03-23T00:46:29.139930 #9289] FATAL -- : [f36ff000-6261-4c2c-bfcc-4a2f80cae682] app/views/home/index.html.erb:1:in `_app_views_home_index_html_erb__177499641769

经过数小时的研究，我仍然不明白为什么我可以访问样式表中的预编译图像，但不能在带有 image_tag 的视图中访问。

附加信息：

$ ruby --version
ruby 2.4.3p205 (2017-12-14 revision 61247) [x86_64-linux]

$ rails --version
Rails 5.1.4

/config/application.rb:

require_relative 'boot'

require 'rails/all'

# Require the gems listed in Gemfile, including any gems
# you've limited to :test, :development, or :production.
Bundler.require(*Rails.groups)

module SimsonSeelig
  class Application < Rails::Application
    # Initialize configuration defaults for originally generated Rails version.
    config.load_defaults 5.1

    # Settings in config/environments/* take precedence over those specified here.
    # Application configuration should go into files in config/initializers
    # -- all .rb files in that directory are automatically loaded.

    # Enable rails to serve my assets
    config.serve_static_assets = true
  end
end

production.rb:

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

  # Attempt to read encrypted secrets from `config/secrets.yml.enc`.
  # Requires an encryption key in `ENV["RAILS_MASTER_KEY"]` or
  # `config/secrets.yml.key`.
  config.read_encrypted_secrets = true

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

  if ENV["RAILS_LOG_TO_STDOUT"].present?
    logger           = ActiveSupport::Logger.new(STDOUT)
    logger.formatter = config.log_formatter
    config.logger = ActiveSupport::TaggedLogging.new(logger)
  end

  # 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 = false

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

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

  # 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

  # Mount Action Cable outside main process or domain
  # config.action_cable.mount_path = nil
  # config.action_cable.url = 'wss://example.com/cable'
  # config.action_cable.allowed_request_origins = [ 'http://example.com', /http:\/\/example.*/ ]

  # 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 = [ :request_id ]

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

  # Use a real queuing backend for Active Job (and separate queues per environment)
  # config.active_job.queue_adapter     = :resque
  # config.active_job.queue_name_prefix = "simson-seelig_#{Rails.env}"
  config.action_mailer.perform_caching = false

  # 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

  # Use a different logger for distributed setups.
  # require 'syslog/logger'
  # config.logger = ActiveSupport::TaggedLogging.new(Syslog::Logger.new 'app-name')

  if ENV["RAILS_LOG_TO_STDOUT"].present?
    logger           = ActiveSupport::Logger.new(STDOUT)
    logger.formatter = config.log_formatter
    config.logger    = ActiveSupport::TaggedLogging.new(logger)
  end

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

/config/initializers/assets.rb:

# Be sure to restart your server when you modify this file.

# Version of your assets, change this if you want to expire all your assets.
Rails.application.config.assets.version = '1.0'

# Add additional assets to the asset load path.
# Rails.application.config.assets.paths << Emoji.images_path
# Add Yarn node_modules folder to the asset load path.
Rails.application.config.assets.paths << Rails.root.join('node_modules')

# Precompile additional assets.
# application.js, application.css, and all non-JS/CSS in the app/assets
# folder are already added.
# Rails.application.config.assets.precompile += %w( admin.js admin.css )

【问题讨论】：

应该没什么区别。在接受的答案下方查看我的评论。

标签： ruby-on-rails asset-pipeline production-environment

【解决方案1】：

我在 Ubuntu 20.04 中处理 Rails 6 应用程序时遇到了同样的问题。

对我来说，问题是我没有在生产环境中预编译资产。

这是我修复它的方法：

首先，我运行以下命令来预编译资产并使其在我的应用程序的public 目录中可用：

rails assets:precompile RAILS_ENV=production

注意：在开发中，这可以使用webpacker 和命令：/bin/webpack-dev-server

接下来，设置 Nginx 或 Apache 网络服务器以提供在我的应用程序的 public 目录中可用的静态文件。对我来说，我使用 Let's Encrypt for SSL 使用以下配置设置 Nginx：

upstream railsserver {
        server 127.0.0.1:3000;
}

server {

        # Replace 'localhost' with your FQDN if you want to use
        # your app from remote or if you need to add a certificate 
        server_name my-website.com www.my-website.com;
                        
        root /home/deploy/my-website/public;

        # Define where Nginx should write its logs
        access_log /var/log/nginx/my-website/access.log;
        error_log /var/log/nginx/my-website/error.log;

        location / {
            # First attempt to serve request as file, then
            # the rails application directory
            try_files $uri @railsserver;
        }
       
        location ~ ^/(assets/|robots.txt|humans.txt|favicon.ico) {
                expires max;
        }

        location @railsserver {
                proxy_set_header Host $http_host;
                proxy_set_header CLIENT_IP $remote_addr;
                proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
                proxy_set_header X-Forwarded-Proto $scheme;
                proxy_read_timeout 300;
                proxy_pass http://railsserver;

                gzip on;
                gzip_types text/plain text/xml text/css image/svg+xml application/javas$
                gzip_proxied any;
        }

        listen [::]:443 ssl ipv6only=on; # managed by Certbot
        listen 443 ssl; # managed by Certbot
        ssl_certificate /etc/letsencrypt/live/my-website.com/fullchain.pem; # managed by Certbot
        ssl_certificate_key /etc/letsencrypt/live/my-website.com/privkey.pem; # managed by Certbot
        include /etc/letsencrypt/options-ssl-nginx.conf; # managed by Certbot
        ssl_dhparam /etc/letsencrypt/ssl-dhparams.pem; # managed by Certbot
}

就是这样。

我希望这会有所帮助

【讨论】：

【解决方案2】：

发生在我身上是因为我的图片放错了地方。对于 rails 6，将图像放入 /app/assets/images/，然后简单地

<%= image_tag("logo1.png", alt: "My logo", size: '200x75') %>

【讨论】：

【解决方案3】：

不确定是否要在生产环境中设置 config.assets.compile = true，这会降低服务器速度

config.assets.compile=true in Rails production, why not?

而不是显式设置 config.assets.compile = false。评论它对我有用，这可能是一个错误。注释掉后，使用预编译的资产管道正确渲染了图像。

# config.assets.compile = false

【讨论】：

【解决方案4】：

资产“aussen”不在资产管道中。

技术上是正确的，因为你没有aussen，但你有aussen.jpg，所以它将是<%= image_tag("aussen.jpg") %>

看，当你使用 <%= image_tag("aussen") %> 时，它会生成这样的 HTML

<%= image_tag("aussen") %>
#=> <img alt="Aussen" src="/assets/aussen" />

当您使用<%= image_tag("aussen.jpg") %> 时，它将像这样生成 HTML

<%= image_tag("aussen.jpg") %>
#=> <img alt="Aussen" src="/assets/aussen.jpg" />

当它进入生产模式时，它将在页面源上显示一些加密密钥，如下所示

aussen-d2fb0029a12281121a1752c599e715a8e2b3db17f1e8e18248a79a7b1ca63b91.jpg

image_tagAssetTagHelper 请参阅此内容。

将production.rb文件config.assets.compilefalse更新为true

# config/environments/production.rb
...
config.assets.compile = true
...

【讨论】：

config.assets.compile = true 成功了！非常感谢！
<%= image_tag("aussen") %> 有效。它指向<img src="/assets/aussen-d2fb0029a12281121a1752c599e715a8e2b3db17f1e8e18248a79a7b1ca63b91.jpg" >
太棒了！太棒了:)
这会使您的生产应用程序暴露于一个重大漏洞。 不要这样做