Support LFS objects when creating a project by import

1 files changed, 93 insertions, 0 deletions

diff --git a/app/services/projects/lfs_pointers/lfs_download_link_list_service.rb b/app/services/projects/lfs_pointers/lfs_download_link_list_service.rb
new file mode 100644
index 00000000000..d9fb74b090e
--- /dev/null
+++ b/app/services/projects/lfs_pointers/lfs_download_link_list_service.rb
@@ -0,0 +1,93 @@
+# This service lists the download link from a remote source based on the
+# oids provided
+module Projects
+  module LfsPointers
+    class LfsDownloadLinkListService < BaseService
+      DOWNLOAD_ACTION = 'download'.freeze
+
+      DownloadLinksError = Class.new(StandardError)
+      DownloadLinkNotFound = Class.new(StandardError)
+
+      attr_reader :remote_uri
+
+      def initialize(project, remote_uri: nil)
+        super(project)
+
+        @remote_uri = remote_uri
+      end
+
+      # This method accepts two parameters:
+      # - oids: hash of oids to query. The structure is { lfs_file_oid => lfs_file_size }
+      #
+      # Returns a hash with the structure { lfs_file_oids => download_link }
+      def execute(oids)
+        return {} unless project&.lfs_enabled? && remote_uri && oids.present?
+
+        get_download_links(oids)
+      end
+
+      private
+
+      def get_download_links(oids)
+        response = Gitlab::HTTP.post(remote_uri,
+                                     body: request_body(oids),
+                                     headers: headers)
+
+        raise DownloadLinksError, response.message unless response.success?
+
+        parse_response_links(response['objects'])
+      end
+
+      def parse_response_links(objects_response)
+        objects_response.each_with_object({}) do |entry, link_list|
+          begin
+            oid = entry['oid']
+            link = entry.dig('actions', DOWNLOAD_ACTION, 'href')
+
+            raise DownloadLinkNotFound unless link
+
+            link_list[oid] = add_credentials(link)
+          rescue DownloadLinkNotFound, URI::InvalidURIError
+            Rails.logger.error("Link for Lfs Object with oid #{oid} not found or invalid.")
+          end
+        end
+      end
+
+      def request_body(oids)
+        {
+          operation: DOWNLOAD_ACTION,
+          objects: oids.map { |oid, size| { oid: oid, size: size } }
+        }.to_json
+      end
+
+      def headers
+        {
+          'Accept' => LfsRequest::CONTENT_TYPE,
+          'Content-Type' => LfsRequest::CONTENT_TYPE
+        }.freeze
+      end
+
+      def add_credentials(link)
+        uri = URI.parse(link)
+
+        if should_add_credentials?(uri)
+          uri.user = remote_uri.user
+          uri.password = remote_uri.password
+        end
+
+        uri.to_s
+      end
+
+      # The download link can be a local url or an object storage url
+      # If the download link has the some host as the import url then
+      # we add the same credentials because we may need them
+      def should_add_credentials?(link_uri)
+        url_credentials? && link_uri.host == remote_uri.host
+      end
+
+      def url_credentials?
+        remote_uri.user.present? || remote_uri.password.present?
+      end
+    end
+  end
+end