CODEWITHSUNDEEP
ruby-on-railsruby-on-rails-5rails-activestorage
claasz
claasz

Reputation: 2134

How to disable ActiveStorage Analyzers and Previewers

I have a Rails 5.2.3 app using ActiveStorage. By default, ActiveStorage would run some background jobs to extract metadata from attached files, and/or create thumbnail images for previews.

I don't want that. I don't need any metadata, nor do I need any thumbnails. So how can I disable these background jobs?

According to the official Rails guide, I've set

config.active_storage.analyzers = []
config.active_storage.previewers = []

in /config/application.rb.

However, looks like it doesn't help. When running rails test, I still see 

[ActiveJob] [ActiveStorage::AnalyzeJob] Performing ActiveStorage::AnalyzeJob (Job ID: 741592f5-c5e4-48d7-8cf9-158790fb8a00) from Inline(default) with arguments: #<GlobalID:0x00005642f9050748 @uri=#<URI::GID >>
[ActiveJob] [ActiveStorage::AnalyzeJob] (22.0ms)  SAVEPOINT active_record_1
[ActiveJob] [ActiveStorage::AnalyzeJob] ActiveStorage::Blob Update (22.7ms)  UPDATE `active_storage_blobs` SET `metadata` = '{\"identified\":true,\"analyzed\":true}' WHERE `active_storage_blobs`.`id` = 3056
[ActiveJob] [ActiveStorage::AnalyzeJob] (21.9ms)  RELEASE SAVEPOINT active_record_1

I've also tried via an initializer file:

# /config/initializers/active_storage_disable_analyze.rb
Rails.application.config.active_storage.analyzers.delete ActiveStorage::Analyzer::ImageAnalyzer
Rails.application.config.active_storage.analyzers.delete ActiveStorage::Analyzer::VideoAnalyzer

But this doesn't help neither.

Upvotes: 7

Views: 8896

Answers (5)

ejoubaud
ejoubaud

Reputation: 5241

You can remove the Analyzers globally, which will only end up running the NullAnalyzer:

ActiveStorage.analyzers = []

For something more selective, you can wrap them in a subclass that overrides their .accept?(blob).

For instance we use a custom ActiveStorage service class to encrypt some uploads, but it doesn't support the streaming download used by ActiveStorage::AnalyzeJob. We disabled the analyze only for attachments using that service this way:

ActiveStorage.analyzers.map! do |klass|
  Class.new(klass) do
    def self.accept?(blob)
      return false if blob.service.is_a?(EncryptedS3Service)
      super
    end
  end
end

Upvotes: 0

Martin Chan
Martin Chan

Reputation: 21

I prefer a clear way by removing the auto call.

Rails.application.config.to_prepare do
  ActiveStorage::Attachment.skip_callback(:commit, :after, :analyze_blob_later)
end

Upvotes: 2

raykin
raykin

Reputation: 1757

config/initializers/override_as_blob.rb

Rails.application.config.to_prepare do
  ActiveStorage::Blob.class_eval do
    def analyzed?
    # Do whatever override
      if checksum.blank?
        true
      else
        super
      end
    end
  end
end

Upvotes: 2

aqwan
aqwan

Reputation: 500

I did not want or need any analysis at all, ever, and over-riding the module methods seemed to do the trick. 

ActiveStorage::Blob::Analyzable.module_eval do

  def analyze_later
  end

  def analyzed?
    true
  end
end

Quite early days so I cannot guarantee no side effects but so far so good, no longer seeing any ActiveStorage::AnalyzeJob entries in my sidekiq log and the blobs seem perfectly usable, download links work etc.

Upvotes: 5

Mark Merritt
Mark Merritt

Reputation: 2695

There is no easy way to disable Analyzers completely. Rails falls back to NullAnalyzer when you delete the Image/Video analyzers, which doesn't gather any metadata.

You can see where it defaults here

Upvotes: 2

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