reafactor: deprecate legacy handlers and context

Signed-off-by: Camila Belo <camilaibs@gmail.com>

.changeset/spicy-camels-happen.md

@@ -0,0 +1,5 @@
+---
+'@backstage/backend-common': patch
+---
+
+We are deprecating the legacy router handlers and contexts in preparation for the new backend system stable release.

packages/backend-common/api-report-alpha.md

@@ -5,14 +5,14 @@
 ```ts
 import { Duration } from 'luxon';
 
-// @alpha
+// @alpha @deprecated
 export interface Context {
   readonly abortSignal: AbortSignal;
   readonly deadline: Date | undefined;
   value<T = unknown>(key: string): T | undefined;
 }
 
-// @alpha
+// @alpha @deprecated
 export class Contexts {
   static root(): Context;
   static withAbort(

packages/backend-common/api-report.md

@@ -309,7 +309,7 @@ export function dropDatabase(
   ...databaseNames: string[]
 ): Promise<void>;
 
-// @public
+// @public @deprecated
 export function errorHandler(
   options?: ErrorHandlerOptions,
 ): ErrorRequestHandler;
@@ -532,7 +532,7 @@ export class HarnessUrlReader implements UrlReader {
   toString(): string;
 }
 
-// @public
+// @public @deprecated
 export const HostDiscovery: typeof HostDiscovery_2;
 
 // @public @deprecated (undocumented)
@@ -733,7 +733,7 @@ export function redactWinstonLogLine(
   info: winston.Logform.TransformableInfo,
 ): winston.Logform.TransformableInfo;
 
-// @public
+// @public @deprecated
 export function requestLoggingHandler(logger?: LoggerService): RequestHandler;
 
 // @public

packages/backend-common/src/context/Contexts.ts

@@ -24,6 +24,7 @@ import { ValueContext } from './ValueContext';
  * Common context decorators.
  *
  * @alpha
+ * @deprecated This class is not used in the new Backend system, so it is going to be removed in a near future.
  */
 export class Contexts {
   /**

packages/backend-common/src/context/types.ts

@@ -19,6 +19,7 @@
  * to pass along scoped information and abort signals.
  *
  * @alpha
+ * @deprecated This type is not used in the new Backend system, so it is going to be removed in a near future.
  */
 export interface Context {
   /**

packages/backend-common/src/discovery/HostDiscovery.ts

@@ -27,6 +27,7 @@ export type { DiscoveryService as PluginEndpointDiscovery } from '@backstage/bac
  * resolved to the same host, so there won't be any balancing of internal traffic.
  *
  * @public
+ * @deprecated Please import from `@backstage/backend-defaults/discovery` instead.
  */
 export const HostDiscovery = _HostDiscovery;
 

packages/backend-common/src/middleware/errorHandler.ts

@@ -61,6 +61,7 @@ export type ErrorHandlerOptions = {
  *
  * @public
  * @returns An Express error request handler
+ * @deprecated Use {@link @backstage/backend-app-api#MiddlewareFactory.create.error} instead
  */
 export function errorHandler(
   options: ErrorHandlerOptions = {},

packages/backend-common/src/middleware/requestLoggingHandler.ts

@@ -26,6 +26,7 @@ import { ConfigReader } from '@backstage/config';
  * @public
  * @param logger - An optional logger to use. If not specified, the root logger will be used.
  * @returns An Express request handler
+ * @deprecated @deprecated Use {@link @backstage/backend-app-api#MiddlewareFactory.create.logging} instead
  */
 export function requestLoggingHandler(logger?: LoggerService): RequestHandler {
   return MiddlewareFactory.create({

plugins/permission-node/src/integration/createPermissionIntegrationRouter.ts

@@ -481,6 +481,7 @@ export function createPermissionIntegrationRouter<
     },
   );
 
+  // TODO(belugas): Remove this when dropping support to the legacy backend system because setting the error handler manually is no logger required in the new system.
   router.use(errorHandler());
 
   return router;