backend-common: reimplement createRootLogger using WinstonLogger

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

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

@@ -0,0 +1,79 @@
+/*
+ * Copyright 2020 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 { WinstonLogger } from '@backstage/backend-app-api';
+import { merge } from 'lodash';
+import * as winston from 'winston';
+import { LoggerOptions } from 'winston';
+import { setRootLogger } from './globalLoggers';
+
+const redacter = WinstonLogger.redacter();
+
+export const setRootLoggerRedactionList = redacter.add;
+
+/**
+ * A winston formatting function that finds occurrences of filteredKeys
+ * and replaces them with the corresponding identifier.
+ *
+ * @public
+ */
+export const redactWinstonLogLine: (
+  info: winston.Logform.TransformableInfo,
+) => winston.Logform.TransformableInfo | boolean = redacter.format.transform;
+
+/**
+ * Creates a default "root" logger. This also calls {@link setRootLogger} under
+ * the hood.
+ *
+ * @remarks
+ *
+ * This is the logger instance that will be the foundation for all other logger
+ * instances passed to plugins etc, in a given backend.
+ *
+ * @public
+ */
+export function createRootLogger(
+  options: winston.LoggerOptions = {},
+  env = process.env,
+): winston.Logger {
+  const logger = winston
+    .createLogger(
+      merge<LoggerOptions, LoggerOptions>(
+        {
+          level: env.LOG_LEVEL || 'info',
+          format: winston.format.combine(
+            redacter.format,
+            env.NODE_ENV === 'production'
+              ? winston.format.json()
+              : WinstonLogger.colorFormat(),
+          ),
+          transports: [
+            new winston.transports.Console({
+              silent: env.JEST_WORKER_ID !== undefined && !env.LOG_LEVEL,
+            }),
+          ],
+        },
+        options,
+      ),
+    )
+    .child({ service: 'backstage' });
+
+  setRootLogger(logger);
+
+  return logger;
+}
+
+setRootLogger(createRootLogger());

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

@@ -27,7 +27,7 @@ export function getVoidLogger(): winston.Logger {
   });
 }
 
-let rootLogger: winston.Logger = createRootLogger();
+let rootLogger: winston.Logger;
 
 /**
  * Gets the current root logger.

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

@@ -15,4 +15,5 @@
  */
 
 export { getRootLogger, getVoidLogger, setRootLogger } from './globalLoggers';
+export { createRootLogger } from './createRootLogger';
 export { loggerToWinstonLogger } from './loggerToWinstonLogger';