Rails ActiveStorage附加到现有S3文件

时间:2018-09-14 01:53:13

标签: amazon-s3 rails-activestorage ruby-on-rails-5.2

我正在构建一个PDF解析器,该解析器将触发Sidekiq工作者以OCR解析S3中存储的文档中的数据。解析后,数据存储在Document模型中。

如何在不通过S3复制文件(通过File.open等)的情况下将现有S3存储桶文件附加到ActiveStorage中的Document.attachment.attach

2 个答案:

答案 0 :(得分:5)

特洛伊的答案对我很有用!我还发现从对象的s3实例中提取有关该对象的元数据很有帮助。像这样:

s3 = Aws::S3::Resource.new(region: "us-west-1")
obj = s3.bucket("my-bucket").object("myfile.jpg")    

params = {
    filename: obj.key, 
    content_type: obj.content_type, 
    byte_size: obj.size, 
    checksum: obj.etag.gsub('"',"")
}

我只有46分,所以我将其留为答案而不是评论:/

答案 1 :(得分:4)

可以在创建Blob之后对其进行一点操作。

storage.yml

amazon:
  service: S3
  access_key_id: <%= ENV['AWS_ACCESS_KEY_ID'] %>
  secret_access_key: <%= ENV['AWS_SECRET_ACCESS_KEY'] %>
  region: <%= ENV['AWS_REGION'] %>
  bucket: <%= ENV['S3_BUCKET'] %>

app / models / document.rb

class Document < ApplicationRecord
  has_one_attached :pdf
end

铁路控制台

key = "<S3 Key of the existing file in the same bucket that storage.yml uses>"

# Create an active storage blob that will represent the file on S3
params = { 
  filename: "myfile.jpg", 
  content_type:"image/jpeg", 
  byte_size:1234, 
  checksum:"<Base 64 encoding of the MD5 hash of the file's contents>" 
}
blob = ActiveStorage::Blob.create_before_direct_upload!(params)

# By default, the blob's key (S3 key, in this case) a secure (random) token
# However, since the file is already on S3, we need to change the 
# key to match our file on S3
blob.update_attributes key:key

# Now we can create a document object connected to your S3 file
d = Document.create! pdf:blob.signed_id

# in your view, you can now use
url_for d.pdf

这时,您可以像使用任何其他活动存储附件一样使用pdf对象的Document属性。