Extend API for exporting a project with direct upload URL

6 files changed, 216 insertions, 2 deletions

diff --git a/lib/api/project_export.rb b/lib/api/project_export.rb
index efc4a33ae1b..5ef4e9d530c 100644
--- a/lib/api/project_export.rb
+++ b/lib/api/project_export.rb
@@ -33,11 +33,28 @@ module API
       end
       params do
         optional :description, type: String, desc: 'Override the project description'
+        optional :upload, type: Hash do
+          optional :url, type: String, desc: 'The URL to upload the project'
+          optional :http_method, type: String, default: 'PUT', desc: 'HTTP method to upload the exported project'
+        end
       end
       post ':id/export' do
         project_export_params = declared_params(include_missing: false)
+        after_export_params = project_export_params.delete(:upload) || {}
 
-        user_project.add_export_job(current_user: current_user, params: project_export_params)
+        export_strategy = if after_export_params[:url].present?
+                            params = after_export_params.slice(:url, :http_method).symbolize_keys
+
+                            Gitlab::ImportExport::AfterExportStrategies::WebUploadStrategy.new(params)
+                          end
+
+        if export_strategy&.invalid?
+          render_validation_error!(export_strategy)
+        else
+          user_project.add_export_job(current_user: current_user,
+                                      after_export_strategy: export_strategy,
+                                      params: project_export_params)
+        end
 
         accepted!
       end
diff --git a/lib/gitlab/import_export/after_export_strategies/base_after_export_strategy.rb b/lib/gitlab/import_export/after_export_strategies/base_after_export_strategy.rb
new file mode 100644
index 00000000000..aef371d81eb
--- /dev/null
+++ b/lib/gitlab/import_export/after_export_strategies/base_after_export_strategy.rb
@@ -0,0 +1,83 @@
+module Gitlab
+  module ImportExport
+    module AfterExportStrategies
+      class BaseAfterExportStrategy
+        include ActiveModel::Validations
+        extend Forwardable
+
+        StrategyError = Class.new(StandardError)
+
+        AFTER_EXPORT_LOCK_FILE_NAME = '.after_export_action'.freeze
+
+        private
+
+        attr_reader :project, :current_user
+
+        public
+
+        def initialize(attributes = {})
+          @options = OpenStruct.new(attributes)
+
+          self.class.instance_eval do
+            def_delegators :@options, *attributes.keys
+          end
+        end
+
+        def execute(current_user, project)
+          return unless project&.export_project_path
+
+          @project = project
+          @current_user = current_user
+
+          if invalid?
+            log_validation_errors
+
+            return
+          end
+
+          create_or_update_after_export_lock
+          strategy_execute
+
+          true
+        rescue => e
+          project.import_export_shared.error(e)
+          false
+        ensure
+          delete_after_export_lock
+        end
+
+        def to_json(options = {})
+          @options.to_h.merge!(klass: self.class.name).to_json
+        end
+
+        def self.lock_file_path(project)
+          return unless project&.export_path
+
+          File.join(project.export_path, AFTER_EXPORT_LOCK_FILE_NAME)
+        end
+
+        protected
+
+        def strategy_execute
+          raise NotImplementedError
+        end
+
+        private
+
+        def create_or_update_after_export_lock
+          FileUtils.touch(self.class.lock_file_path(project))
+        end
+
+        def delete_after_export_lock
+          lock_file = self.class.lock_file_path(project)
+
+          FileUtils.rm(lock_file) if lock_file.present? && File.exist?(lock_file)
+        end
+
+        def log_validation_errors
+          errors.full_messages.each { |msg| project.import_export_shared.add_error_message(msg) }
+        end
+      end
+    end
+  end
+end
diff --git a/lib/gitlab/import_export/after_export_strategies/download_notification_strategy.rb b/lib/gitlab/import_export/after_export_strategies/download_notification_strategy.rb
new file mode 100644
index 00000000000..4371a7eff56
--- /dev/null
+++ b/lib/gitlab/import_export/after_export_strategies/download_notification_strategy.rb
@@ -0,0 +1,17 @@
+module Gitlab
+  module ImportExport
+    module AfterExportStrategies
+      class DownloadNotificationStrategy < BaseAfterExportStrategy
+        private
+
+        def strategy_execute
+          notification_service.project_exported(project, current_user)
+        end
+
+        def notification_service
+          @notification_service ||= NotificationService.new
+        end
+      end
+    end
+  end
+end
diff --git a/lib/gitlab/import_export/after_export_strategies/web_upload_strategy.rb b/lib/gitlab/import_export/after_export_strategies/web_upload_strategy.rb
new file mode 100644
index 00000000000..938664a95a1
--- /dev/null
+++ b/lib/gitlab/import_export/after_export_strategies/web_upload_strategy.rb
@@ -0,0 +1,61 @@
+module Gitlab
+  module ImportExport
+    module AfterExportStrategies
+      class WebUploadStrategy < BaseAfterExportStrategy
+        PUT_METHOD = 'PUT'.freeze
+        POST_METHOD = 'POST'.freeze
+        INVALID_HTTP_METHOD = 'invalid. Only PUT and POST methods allowed.'.freeze
+
+        validates :url, url: true
+
+        validate do
+          unless [PUT_METHOD, POST_METHOD].include?(http_method.upcase)
+            errors.add(:http_method, INVALID_HTTP_METHOD)
+          end
+        end
+
+        def initialize(url:, http_method: PUT_METHOD)
+          super
+        end
+
+        protected
+
+        def strategy_execute
+          handle_response_error(send_file)
+
+          project.remove_exported_project_file
+        end
+
+        def handle_response_error(response)
+          unless response.success?
+            error_code = response.dig('Error', 'Code') || response.code
+            error_message = response.dig('Error', 'Message') || response.message
+
+            raise StrategyError.new("Error uploading the project. Code #{error_code}: #{error_message}")
+          end
+        end
+
+        private
+
+        def send_file
+          export_file = File.open(project.export_project_path)
+
+          Gitlab::HTTP.public_send(http_method.downcase, url, send_file_options(export_file)) # rubocop:disable GitlabSecurity/PublicSend
+        ensure
+          export_file.close if export_file
+        end
+
+        def send_file_options(export_file)
+          {
+            body_stream: export_file,
+            headers: headers
+          }
+        end
+
+        def headers
+          { 'Content-Length' => File.size(project.export_project_path).to_s }
+        end
+      end
+    end
+  end
+end
diff --git a/lib/gitlab/import_export/after_export_strategy_builder.rb b/lib/gitlab/import_export/after_export_strategy_builder.rb
new file mode 100644
index 00000000000..7eabcae2380
--- /dev/null
+++ b/lib/gitlab/import_export/after_export_strategy_builder.rb
@@ -0,0 +1,24 @@
+module Gitlab
+  module ImportExport
+    class AfterExportStrategyBuilder
+      StrategyNotFoundError = Class.new(StandardError)
+
+      def self.build!(strategy_klass, attributes = {})
+        return default_strategy.new unless strategy_klass
+
+        attributes ||= {}
+        klass = strategy_klass.constantize rescue nil
+
+        unless klass && klass < AfterExportStrategies::BaseAfterExportStrategy
+          raise StrategyNotFoundError.new("Strategy #{strategy_klass} not found")
+        end
+
+        klass.new(**attributes.symbolize_keys)
+      end
+
+      def self.default_strategy
+        AfterExportStrategies::DownloadNotificationStrategy
+      end
+    end
+  end
+end
diff --git a/lib/gitlab/import_export/shared.rb b/lib/gitlab/import_export/shared.rb
index 3d3d998a6a3..6d7c36ce38b 100644
--- a/lib/gitlab/import_export/shared.rb
+++ b/lib/gitlab/import_export/shared.rb
@@ -22,7 +22,7 @@ module Gitlab
 
       def error(error)
         error_out(error.message, caller[0].dup)
-        @errors << error.message
+        add_error_message(error.message)
 
         # Debug:
         if error.backtrace
@@ -32,6 +32,14 @@ module Gitlab
         end
       end
 
+      def add_error_message(error_message)
+        @errors << error_message
+      end
+
+      def after_export_in_progress?
+        File.exist?(after_export_lock_file)
+      end
+
       private
 
       def relative_path
@@ -45,6 +53,10 @@ module Gitlab
       def error_out(message, caller)
         Rails.logger.error("Import/Export error raised on #{caller}: #{message}")
       end
+
+      def after_export_lock_file
+        AfterExportStrategies::BaseAfterExportStrategy.lock_file_path(project)
+      end
     end
   end
 end