Heroku，Shrine和Amazon S3：博客文章图像在一段时间后消失

Question

我有一个使用Rails 5.1开发的博客页面。一切正常，除了在生产中创建帖子并附加图像之后，图像会在一段时间（例如30分钟）后停止显示。我在互联网上搜寻解决方案，发现this表示问题与每次重新启动应用程序后擦除Heroku有关。提供的一种解决方案是将图像托管在Amazon S3之类的服务上。

但是我已经设置了S3，图像正被发送到如下所示的存储桶：

但是，博客文章图像仍然消失。我需要帮助，因为我无法弄清自己的缺失。以下是相关代码：

shrine.rb：

require "shrine"
require "shrine/storage/s3"
s3_options = {
    access_key_id:      ENV['S3_KEY'],
    secret_access_key:  ENV['S3_SECRET'],
    region:             ENV['S3_REGION'],
    bucket:             ENV['S3_BUCKET'],
}

if Rails.env.development?
  require "shrine/storage/file_system"
  Shrine.storages = {
    cache: Shrine::Storage::FileSystem.new("public", prefix: "uploads/cache"), # temporary
    store: Shrine::Storage::FileSystem.new("public", prefix: "uploads/store")  # permanent
  }
elsif Rails.env.test?
  require 'shrine/storage/memory'
  Shrine.storages = {
    cache: Shrine::Storage::Memory.new,
    store: Shrine::Storage::Memory.new
  }
else
  require "shrine/storage/s3"

  Shrine.storages = {
    cache: Shrine::Storage::S3.new(prefix: "cache", **s3_options),
    store: Shrine::Storage::S3.new(prefix: "store", **s3_options)
  }
end
Shrine.plugin :activerecord # or :activerecord
Shrine.plugin :cached_attachment_data # for retaining the cached file across form redisplays

gemfile：

....................................
# A rich text editor for everyday writing
gem 'trix', '~> 0.11.1'
# a toolkit for file attachments in Ruby applications
gem 'shrine', '~> 2.11'
# Tag a single model on several contexts, such as skills, interests, and awards
gem 'acts-as-taggable-on', '~> 6.0'
# frameworks for multiple-provider authentication.
gem 'omniauth-facebook'
gem 'omniauth-github'
# Simple Rails app key configuration
gem "figaro"
..............................

我使用Figaro gem掩盖环境文件。由于S3存储桶响应，它们很好，而且我已经在博客上启动并运行了OmniAuth。

这是在chrome控制台上显示的图片错误：

我真的需要帮助来启动和运行此博客。谢谢您的宝贵时间。

Answer 1

默认情况下，Shrine会生成过期的S3 URL，因此很有可能缓存了生成的URL，一旦URL过期，图像就变得不可用。

作为一种解决方法，您可以使S3上传成为公开的，并生成公共URL。您可以通过告诉S3存储将上传设为公开（请注意，这只会影响新的上传，现有的上传将保持私有，因此您必须以其他方式将其公开）来做到这一点，并默认生成公共网址，通过更新初始化程序：

# ...

require "shrine/storage/s3"

Shrine.storages = {
  cache: Shrine::Storage::S3.new(prefix: "cache", upload_options: { acl: "public-read" }, **s3_options),
  store: Shrine::Storage::S3.new(prefix: "store", upload_options: { acl: "public-read" }, **s3_options)
}

# ...

Shrine.plugin :default_url_options, cache: { public: true }, store: { public: true }

# ...