added a rake task to clean orphan uploaded files

lib/local_store.rb

@@ -15,4 +15,9 @@ module LocalStore
     return Discourse::base_uri + "#{url_root}/#{clean_name}"
   end
 
+  def self.remove_file(url)
+    File.delete("#{Rails.root}/public#{url}")
+  rescue Errno::ENOENT
+  end
+
 end

lib/s3.rb

@@ -1,22 +1,44 @@
 module S3
 
   def self.store_file(file, sha1, image_info, upload_id)
-    raise Discourse::SiteSettingMissing.new("s3_upload_bucket")     if SiteSetting.s3_upload_bucket.blank?
-    raise Discourse::SiteSettingMissing.new("s3_access_key_id")     if SiteSetting.s3_access_key_id.blank?
-    raise Discourse::SiteSettingMissing.new("s3_secret_access_key") if SiteSetting.s3_secret_access_key.blank?
+    S3.check_missing_site_settings
 
-    @fog_loaded = require 'fog' unless @fog_loaded
+    directory = S3.get_or_create_directory(SiteSetting.s3_upload_bucket)
 
     remote_filename = "#{upload_id}#{sha1}.#{image_info.type}"
 
-    options = S3.generate_options
-    directory = S3.get_or_create_directory(SiteSetting.s3_upload_bucket, options)
     # if this fails, it will throw an exception
     file = S3.upload(file, remote_filename, directory)
-
     return "//#{SiteSetting.s3_upload_bucket}.s3.amazonaws.com/#{remote_filename}"
   end
 
+  def self.remove_file(url)
+    S3.check_missing_site_settings
+
+    directory = S3.get_or_create_directory(SiteSetting.s3_upload_bucket)
+
+    file = S3.destroy(url, directory)
+  end
+
+  def self.check_missing_site_settings
+    raise Discourse::SiteSettingMissing.new("s3_upload_bucket")     if SiteSetting.s3_upload_bucket.blank?
+    raise Discourse::SiteSettingMissing.new("s3_access_key_id")     if SiteSetting.s3_access_key_id.blank?
+    raise Discourse::SiteSettingMissing.new("s3_secret_access_key") if SiteSetting.s3_secret_access_key.blank?
+  end
+
+  def self.get_or_create_directory(name)
+    @fog_loaded = require 'fog' unless @fog_loaded
+
+    options = S3.generate_options
+
+    fog = Fog::Storage.new(options)
+
+    directory = fog.directories.get(name)
+    directory = fog.directories.create(key: name) unless directory
+
+    directory
+  end
+
   def self.generate_options
     options = {
       provider: 'AWS',
@@ -28,14 +50,6 @@ module S3
     options
   end
 
-  def self.get_or_create_directory(name, options)
-    fog = Fog::Storage.new(options)
-    directory = fog.directories.get(name)
-    directory = fog.directories.create(key: name) unless directory
-
-    directory
-  end
-
   def self.upload(file, name, directory)
     directory.files.create(
       key: name,
@@ -45,4 +59,8 @@ module S3
     )
   end
 
+  def self.destroy(name, directory)
+    directory.files.destroy(key: name)
+  end
+
 end

lib/tasks/images.rake

@@ -30,3 +30,22 @@ task "images:reindex" => :environment do
   end
   puts "\ndone."
 end
+
+desc "clean orphan uploaded files"
+task "images:clean_orphans" => :environment do
+  RailsMultisite::ConnectionManagement.each_connection do |db|
+    puts "Cleaning up #{db}"
+    # ligthweight safety net to prevent users from wiping all their uploads out
+    if PostUpload.count == 0 && Upload.count > 0
+      puts "The reverse index is empty. Make sure you run the `images:reindex` task"
+      next
+    end
+    Upload.joins("LEFT OUTER JOIN post_uploads ON uploads.id = post_uploads.upload_id")
+          .where("post_uploads.upload_id IS NULL")
+          .find_each do |u|
+      u.delete
+      putc "."
+    end
+  end
+  puts "\ndone."
+end