backend-plugin-api: moved loggerToWinstonLogger to backend-common

Signed-off-by: Patrik Oldsberg <poldsberg@gmail.com>

packages/backend-common/api-report.md

@@ -29,6 +29,7 @@ import { Knex } from 'knex';
 import { KubeConfig } from '@kubernetes/client-node';
 import { LoadConfigOptionsRemote } from '@backstage/config-loader';
 import { Logger } from 'winston';
+import { LoggerService } from '@backstage/backend-plugin-api';
 import { MergeResult } from 'isomorphic-git';
 import { DiscoveryService as PluginEndpointDiscovery } from '@backstage/backend-plugin-api';
 import { PushResult } from 'isomorphic-git';
@@ -46,6 +47,7 @@ import { SearchOptions } from '@backstage/backend-plugin-api';
 import { SearchResponse } from '@backstage/backend-plugin-api';
 import { SearchResponseFile } from '@backstage/backend-plugin-api';
 import { Server } from 'http';
+import { TransportStreamOptions } from 'winston-transport';
 import { UrlReaderService as UrlReader } from '@backstage/backend-plugin-api';
 import { V1PodTemplateSpec } from '@kubernetes/client-node';
 import * as winston from 'winston';
@@ -515,6 +517,12 @@ export function loadBackendConfig(options: {
   argv: string[];
 }): Promise<Config>;
 
+// @public (undocumented)
+export function loggerToWinstonLogger(
+  logger: LoggerService,
+  opts?: TransportStreamOptions,
+): Logger;
+
 // @public
 export function notFoundHandler(): RequestHandler;
 

packages/backend-common/package.json

@@ -83,6 +83,7 @@
     "tar": "^6.1.12",
     "uuid": "^8.3.2",
     "winston": "^3.2.1",
+    "winston-transport": "^4.5.0",
     "yauzl": "^2.10.0",
     "yn": "^4.0.0"
   },

packages/backend-common/src/logging/index.ts

@@ -22,3 +22,4 @@ export {
   redactWinstonLogLine,
 } from './rootLogger';
 export * from './voidLogger';
+export { loggerToWinstonLogger } from './loggerToWinstonLogger';

packages/backend-common/src/logging/loggerToWinstonLogger.ts

@@ -0,0 +1,63 @@
+/*
+ * Copyright 2022 The Backstage Authors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+import { LoggerService } from '@backstage/backend-plugin-api';
+import { Logger as WinstonLogger, createLogger } from 'winston';
+import Transport, { TransportStreamOptions } from 'winston-transport';
+
+class BackstageLoggerTransport extends Transport {
+  constructor(
+    private readonly backstageLogger: LoggerService,
+    opts?: TransportStreamOptions,
+  ) {
+    super(opts);
+  }
+
+  log(info: unknown, callback: VoidFunction) {
+    if (typeof info !== 'object' || info === null) {
+      callback();
+      return;
+    }
+    const { level, message, ...meta } = info as { [name: string]: unknown };
+    switch (level) {
+      case 'error':
+        this.backstageLogger.error(String(message), meta);
+        break;
+      case 'warn':
+        this.backstageLogger.warn(String(message), meta);
+        break;
+      case 'info':
+        this.backstageLogger.info(String(message), meta);
+        break;
+      case 'debug':
+        this.backstageLogger.debug(String(message), meta);
+        break;
+      default:
+        this.backstageLogger.info(String(message), meta);
+    }
+    callback();
+  }
+}
+
+/** @public */
+export function loggerToWinstonLogger(
+  logger: LoggerService,
+  opts?: TransportStreamOptions,
+): WinstonLogger {
+  return createLogger({
+    transports: [new BackstageLoggerTransport(logger, opts)],
+  });
+}