Extract an abstract class FileService

app/services/geo/file_download_service.rb

 module Geo
-  class FileDownloadService
-    attr_reader :object_type, :object_db_id
-
+  class FileDownloadService < FileService
     LEASE_TIMEOUT = 8.hours.freeze
-    DEFAULT_OBJECT_TYPES = %w[attachment avatar file].freeze
-
-    def initialize(object_type, object_db_id)
-      @object_type = object_type.to_s
-      @object_db_id = object_db_id
-    end
 
     def execute
       try_obtain_lease do |lease|
@@ -21,24 +13,13 @@ module Geo
     private
 
     def downloader
-      klass = downloader_klass_name.constantize
+      klass = "Gitlab::Geo::#{service_klass_name}Downloader".constantize
       klass.new(object_type, object_db_id)
     rescue NameError
       log("Unknown file type: #{object_type}")
       raise
     end
 
-    def downloader_klass_name
-      klass_name =
-        if DEFAULT_OBJECT_TYPES.include?(object_type)
-          'file'
-        else
-          object_type
-        end
-
-      "Gitlab::Geo::#{klass_name.camelize}Downloader"
-    end
-
     def try_obtain_lease
       uuid = Gitlab::ExclusiveLease.new(lease_key, timeout: LEASE_TIMEOUT).try_obtain
 
@@ -64,9 +45,5 @@ module Geo
     def lease_key
       "file_download_service:#{object_type}:#{object_db_id}"
     end
-
-    def log(message)
-      Rails.logger.info "#{self.class.name}: #{message}"
-    end
   end
 end

app/services/geo/file_service.rb

+module Geo
+  class FileService
+    attr_reader :object_type, :object_db_id
+
+    DEFAULT_OBJECT_TYPES = %w[attachment avatar file].freeze
+    DEFAULT_SERVICE_TYPE = 'file'.freeze
+
+    def initialize(object_type, object_db_id)
+      @object_type = object_type.to_s
+      @object_db_id = object_db_id
+    end
+
+    def execute
+      raise NotImplementedError
+    end
+
+    private
+
+    def service_klass_name
+      klass_name =
+        if DEFAULT_OBJECT_TYPES.include?(object_type)
+          DEFAULT_SERVICE_TYPE
+        else
+          object_type
+        end
+
+      klass_name.camelize
+    end
+
+    def log(message)
+      Rails.logger.info "#{self.class.name}: #{message}"
+    end
+  end
+end

app/services/geo/file_upload_service.rb

 module Geo
-  class FileUploadService
-    DEFAULT_OBJECT_TYPES = %w[attachment avatar file].freeze
+  class FileUploadService < FileService
     IAT_LEEWAY = 60.seconds.to_i
 
-    attr_reader :object_type, :object_db_id, :auth_header
+    attr_reader :auth_header
 
     def initialize(params, auth_header)
-      @object_type = params[:type]
-      @object_db_id = params[:id]
+      super(params[:type], params[:id])
       @auth_header = auth_header
     end
 
@@ -22,25 +20,10 @@ module Geo
     private
 
     def uploader_klass
-      uploader_klass_name.constantize
+      "Gitlab::Geo::#{service_klass_name}Uploader".constantize
     rescue NameError
       log("Unknown file type: #{object_type}")
       raise
     end
-
-    def uploader_klass_name
-      klass_name =
-        if DEFAULT_OBJECT_TYPES.include?(object_type)
-          'file'
-        else
-          object_type
-        end
-
-      "Gitlab::Geo::#{klass_name.camelize}Uploader"
-    end
-
-    def log(message)
-      Rails.logger.info "#{self.class.name}: #{message}"
-    end
   end
 end