fix: skip writing RequestLogEntry for Cloud Run with flag enabled (#821)

* Fix to skip writing RequestLogEntry for Cloud Run

* Parse transport to middleware constructor

.readme-partials.yaml

@@ -226,6 +226,8 @@ body: |-
     would be picked up by the Cloud Logging Agent running in Google Cloud managed environment.
     Note that there is also a `useMessageField` option which controls if "message" field is used to store 
     structured, non-text data inside `jsonPayload` field when `redirectToStdout` is set. By default `useMessageField` is always `true`.
+    Set the `skipParentEntryForCloudRun` option to skip creating an entry for the request itself as Cloud Run already automatically creates
+    such log entries. This might become the default behaviour in a next major version.
 
     ```js
     // Imports the Google Cloud client library for Winston

README.md

@@ -303,6 +303,8 @@ decrease logging record loss upon execution termination - since all logs are wri
 would be picked up by the Cloud Logging Agent running in Google Cloud managed environment.
 Note that there is also a `useMessageField` option which controls if "message" field is used to store 
 structured, non-text data inside `jsonPayload` field when `redirectToStdout` is set. By default `useMessageField` is always `true`.
+Set the `skipParentEntryForCloudRun` option to skip creating an entry for the request itself as Cloud Run already automatically creates
+such log entries. This might become the default behaviour in a next major version.
 
 ```js
 // Imports the Google Cloud client library for Winston

src/middleware/express.ts

@@ -35,15 +35,18 @@ type Middleware = ReturnType<typeof commonMiddleware.express.makeMiddleware>;
 
 export async function makeMiddleware(
   logger: winston.Logger,
-  transport: LoggingWinston
+  transport: LoggingWinston,
+  skipParentEntryForCloudRun?: boolean
 ): Promise<Middleware>;
 export async function makeMiddleware(
   logger: winston.Logger,
-  options?: Options
+  options?: Options,
+  skipParentEntryForCloudRun?: boolean
 ): Promise<Middleware>;
 export async function makeMiddleware(
   logger: winston.Logger,
-  optionsOrTransport?: Options | LoggingWinston
+  optionsOrTransport?: Options | LoggingWinston,
+  skipParentEntryForCloudRun?: boolean
 ): Promise<Middleware> {
   let transport: LoggingWinston;
 
@@ -79,8 +82,15 @@ export async function makeMiddleware(
   // parent request log entry that all the request specific logs ("app logs")
   // will nest under. GAE and GCF generate the parent request logs
   // automatically.
+  // Cloud Run also generates the parent request log automatically, but skipping
+  // the parent request entry has to be explicity enabled until the next major
+  // release in which we can change the default behavior.
   let emitRequestLogEntry;
-  if (env !== GCPEnv.APP_ENGINE && env !== GCPEnv.CLOUD_FUNCTIONS) {
+  if (
+    env !== GCPEnv.APP_ENGINE &&
+    env !== GCPEnv.CLOUD_FUNCTIONS &&
+    (env !== GCPEnv.CLOUD_RUN || !skipParentEntryForCloudRun)
+  ) {
     const requestLogName = Log.formatName_(
       projectId,
       `${transport.common.logName}${REQUEST_LOG_SUFFIX}`

test/middleware/express.ts

@@ -144,10 +144,16 @@ describe('middleware/express', () => {
     assert.strictEqual(passedProjectId, FAKE_PROJECT_ID);
   });
 
-  [GCPEnv.APP_ENGINE, GCPEnv.CLOUD_FUNCTIONS].forEach(env => {
+  [GCPEnv.APP_ENGINE, GCPEnv.CLOUD_FUNCTIONS, GCPEnv.CLOUD_RUN].forEach(env => {
     it(`should not generate the request logger on ${env}`, async () => {
       authEnvironment = env;
-      await makeMiddleware(logger);
+      const t = new FakeLoggingWinston({});
+      if (env === GCPEnv.CLOUD_RUN) {
+        // Cloud Run needs explicit set skipParentEntryForCloudRun flag to enable this behavior until we can make breaking change in next major version
+        await makeMiddleware(logger, t, /*skipParentEntryForCloudRun=*/ true);
+      } else {
+        await makeMiddleware(logger, t);
+      }
       assert.ok(passedOptions);
       assert.strictEqual(passedOptions.length, 1);
       // emitRequestLog parameter to makeChildLogger should be undefined.