1 files changed, 103 insertions, 0 deletions
diff --git a/app/services/projects/propagate_service_template.rb b/app/services/projects/propagate_service_template.rb
new file mode 100644
index 00000000000..32ad68673ac
--- /dev/null
+++ b/app/services/projects/propagate_service_template.rb
@@ -0,0 +1,103 @@
+module Projects
+  class PropagateServiceTemplate
+    BATCH_SIZE = 100
+
+    def self.propagate(*args)
+      new(*args).propagate
+    end
+
+    def initialize(template)
+      @template = template
+    end
+
+    def propagate
+      return unless @template&.active
+
+      Rails.logger.info("Propagating services for template #{@template.id}")
+
+      propagate_projects_with_template
+    end
+
+    private
+
+    def propagate_projects_with_template
+      loop do
+        batch = project_ids_batch
+
+        bulk_create_from_template(batch) unless batch.empty?
+
+        break if batch.size < BATCH_SIZE
+      end
+    end
+
+    def bulk_create_from_template(batch)
+      service_list = batch.map do |project_id|
+        service_hash.merge('project_id' => project_id).values
+      end
+
+      Project.transaction do
+        bulk_insert_services(service_hash.keys + ['project_id'], service_list)
+        run_callbacks(batch)
+      end
+    end
+
+    def project_ids_batch
+      Project.connection.select_values(
+        <<-SQL
+          SELECT id
+          FROM projects
+          WHERE NOT EXISTS (
+            SELECT true
+            FROM services
+            WHERE services.project_id = projects.id
+            AND services.type = '#{@template.type}'
+          )
+          AND projects.pending_delete = false
+          AND projects.archived = false
+          LIMIT #{BATCH_SIZE}
+      SQL
+      )
+    end
+
+    def bulk_insert_services(columns, values_array)
+      ActiveRecord::Base.connection.execute(
+        <<-SQL.strip_heredoc
+          INSERT INTO services (#{columns.join(', ')})
+          VALUES #{values_array.map { |tuple| "(#{tuple.join(', ')})" }.join(', ')}
+      SQL
+      )
+    end
+
+    def service_hash
+      @service_hash ||=
+        begin
+          template_hash = @template.as_json(methods: :type).except('id', 'template', 'project_id')
+
+          template_hash.each_with_object({}) do |(key, value), service_hash|
+            value = value.is_a?(Hash) ? value.to_json : value
+            key = Gitlab::Database.postgresql? ? "\"#{key}\"" : "`#{key}`"
+
+            service_hash[key] = ActiveRecord::Base.sanitize(value)
+          end
+        end
+    end
+
+    def run_callbacks(batch)
+      if active_external_issue_tracker?
+        Project.where(id: batch).update_all(has_external_issue_tracker: true)
+      end
+
+      if active_external_wiki?
+        Project.where(id: batch).update_all(has_external_wiki: true)
+      end
+    end
+
+    def active_external_issue_tracker?
+      @template.category == :issue_tracker && !@template.default
+    end
+
+    def active_external_wiki?
+      @template.type == 'ExternalWikiService'
+    end
+  end
+end