feat: automatically use service and revision name in Knative environments (#375)

Fixes #370

Author: DominicKramer

src/configuration.ts

@@ -204,6 +204,14 @@ export class Configuration {
    * @returns {Undefined} - does not return anything
    */
   _checkLocalServiceContext() {
+    // Update June 18, 2019: When running on Cloud Run, Cloud Run
+    //                       on GKE, or any Knative install, the
+    //                       K_SERVICE env var should be used as
+    //                       the service and the K_REVISION env var
+    //                       should be used as the version.  See the
+    //                       Knative runtime contract for more info
+    // (https://github.com/knative/serving/blob/master/docs/runtime-contract.md#process)
+    //
     // Note: The GAE_MODULE_NAME environment variable is set on GAE.
     //       If the code is, in particular, running on GCF, then the
     //       FUNCTION_NAME environment variable is set.
@@ -224,7 +232,10 @@ export class Configuration {
     let service;
     let version;
 
-    if (env.FUNCTION_NAME) {
+    if (env.K_SERVICE) {
+      service = env.K_SERVICE;
+      version = env.K_REVISION;
+    } else if (env.FUNCTION_NAME) {
       service = env.FUNCTION_NAME;
     } else if (env.GAE_SERVICE) {
       service = env.GAE_SERVICE;

test/unit/service-configuration.ts

@@ -36,22 +36,26 @@ function sterilizeServiceConfigEnv() {
     delete process.env[key];
   });
 }
-function setEnv(
-  serviceName: string | null,
-  serviceVersion: string,
-  moduleName: string | null,
-  mv: string,
-  fn: string | null
-) {
+function setEnv(envData: {
+  gaeServiceName: string | null;
+  gaeServiceVersion: string;
+  gaeModuleName: string | null;
+  gaeModuleVersion: string;
+  functionName: string | null;
+  kService: string | null;
+  kRevision: string | null;
+}) {
   Object.assign(
     process.env,
     omitBy(
       {
-        GAE_SERVICE: serviceName,
-        GAE_VERSION: serviceVersion,
-        GAE_MODULE_NAME: moduleName,
-        GAE_MODULE_VERSION: mv,
-        FUNCTION_NAME: fn,
+        GAE_SERVICE: envData.gaeServiceName,
+        GAE_VERSION: envData.gaeServiceVersion,
+        GAE_MODULE_NAME: envData.gaeModuleName,
+        GAE_MODULE_VERSION: envData.gaeModuleVersion,
+        FUNCTION_NAME: envData.functionName,
+        K_SERVICE: envData.kService,
+        K_REVISION: envData.kRevision,
       },
       val => {
         return !is.string(val);
@@ -74,13 +78,15 @@ describe('Testing service configuration', () => {
     'A Configuration uses the function name as the service name on GCF ' +
       'if the service name is not given in the given config',
     () => {
-      setEnv(
-        'someModuleName',
-        '1.0',
-        'InvalidName',
-        'InvalidVersion',
-        'someFunction'
-      );
+      setEnv({
+        gaeServiceName: 'someModuleName',
+        gaeServiceVersion: '1.0',
+        gaeModuleName: 'InvalidName',
+        gaeModuleVersion: 'InvalidVersion',
+        functionName: 'someFunction',
+        kService: null,
+        kRevision: null,
+      });
       const c = new Configuration({}, logger);
       deepStrictEqual(c.getServiceContext().service, 'someFunction');
       // FUNCTION_NAME is set and the user didn't specify a version, and so
@@ -93,7 +99,15 @@ describe('Testing service configuration', () => {
       'if the service name is not given in the given config ' +
       'even if the GAE_SERVICE was not set',
     () => {
-      setEnv(null, '1.0', null, 'InvalidVersion', 'someFunction');
+      setEnv({
+        gaeServiceName: null,
+        gaeServiceVersion: '1.0',
+        gaeModuleName: null,
+        gaeModuleVersion: 'InvalidVersion',
+        functionName: 'someFunction',
+        kService: null,
+        kRevision: null,
+      });
       const c = new Configuration({}, logger);
       deepStrictEqual(c.getServiceContext().service, 'someFunction');
       // The user didn't specify a version and FUNCTION_NAME is defined, and
@@ -106,7 +120,15 @@ describe('Testing service configuration', () => {
       'if the FUNCTION_NAME env variable is not set and the given config ' +
       'does not specify the service name',
     () => {
-      setEnv('someModuleName', '1.0', 'InvalidName', 'InvalidVersion', null);
+      setEnv({
+        gaeServiceName: 'someModuleName',
+        gaeServiceVersion: '1.0',
+        gaeModuleName: 'InvalidName',
+        gaeModuleVersion: 'InvalidVersion',
+        functionName: null,
+        kService: null,
+        kRevision: null,
+      });
       const c = new Configuration({}, logger);
       deepStrictEqual(c.getServiceContext().service, 'someModuleName');
       // The user didn't specify a version, and FUNCTION_NAME is not defined,
@@ -119,13 +141,15 @@ describe('Testing service configuration', () => {
       'was specified and both the GAE_SERVICE and FUNCTION_NAME ' +
       'env vars are set',
     () => {
-      setEnv(
-        'someModuleName',
-        '1.0',
-        'InvalidName',
-        'InvalidVersion',
-        'someFunction'
-      );
+      setEnv({
+        gaeServiceName: 'someModuleName',
+        gaeServiceVersion: '1.0',
+        gaeModuleName: 'InvalidName',
+        gaeModuleVersion: 'InvalidVersion',
+        functionName: 'someFunction',
+        kService: null,
+        kRevision: null,
+      });
       const c = new Configuration(
         {
           serviceContext: {
@@ -145,13 +169,15 @@ describe('Testing service configuration', () => {
       'they were both specified and both the GAE_SERVICE and FUNCTION_NAME ' +
       'env vars are set',
     () => {
-      setEnv(
-        'someModuleName',
-        '1.0',
-        'InvalidName',
-        'InvalidVersion',
-        'someFunction'
-      );
+      setEnv({
+        gaeServiceName: 'someModuleName',
+        gaeServiceVersion: '1.0',
+        gaeModuleName: 'InvalidName',
+        gaeModuleVersion: 'InvalidVersion',
+        functionName: 'someFunction',
+        kService: null,
+        kRevision: null,
+      });
       const c = new Configuration(
         {
           serviceContext: {
@@ -170,7 +196,15 @@ describe('Testing service configuration', () => {
     'A Configuration uses the service name in the given config if it ' +
       'was specified and only the GAE_SERVICE env const is set',
     () => {
-      setEnv('someModuleName', '1.0', 'InvalidName', 'InvalidVersion', null);
+      setEnv({
+        gaeServiceName: 'someModuleName',
+        gaeServiceVersion: '1.0',
+        gaeModuleName: 'InvalidName',
+        gaeModuleVersion: 'InvalidVersion',
+        functionName: null,
+        kService: null,
+        kRevision: null,
+      });
       const c = new Configuration(
         {
           serviceContext: {
@@ -189,7 +223,15 @@ describe('Testing service configuration', () => {
     'A Configuration uses the service name and version in the given config ' +
       'they were both specified and only the GAE_SERVICE env const is set',
     () => {
-      setEnv('someModuleName', '1.0', 'InvalidName', 'InvalidVersion', null);
+      setEnv({
+        gaeServiceName: 'someModuleName',
+        gaeServiceVersion: '1.0',
+        gaeModuleName: 'InvalidName',
+        gaeModuleVersion: 'InvalidVersion',
+        functionName: null,
+        kService: null,
+        kRevision: null,
+      });
       const c = new Configuration(
         {
           serviceContext: {
@@ -208,7 +250,15 @@ describe('Testing service configuration', () => {
     'A Configuration uses the service name in the given config if it ' +
       'was specified and only the FUNCTION_NAME env const is set',
     () => {
-      setEnv(null, '1.0', null, 'InvalidVersion', 'someFunction');
+      setEnv({
+        gaeServiceName: null,
+        gaeServiceVersion: '1.0',
+        gaeModuleName: null,
+        gaeModuleVersion: 'InvalidVersion',
+        functionName: 'someFunction',
+        kService: null,
+        kRevision: null,
+      });
       const c = new Configuration(
         {
           serviceContext: {
@@ -227,7 +277,15 @@ describe('Testing service configuration', () => {
     'A Configuration uses the service name and version in the given config ' +
       'if they were both specified and only the FUNCTION_NAME env const is set',
     () => {
-      setEnv(null, '1.0', null, 'InvalidVersion', 'someFunction');
+      setEnv({
+        gaeServiceName: null,
+        gaeServiceVersion: '1.0',
+        gaeModuleName: null,
+        gaeModuleVersion: 'InvalidVersion',
+        functionName: 'someFunction',
+        kService: null,
+        kRevision: null,
+      });
       const c = new Configuration(
         {
           serviceContext: {
@@ -258,7 +316,15 @@ describe('Testing service configuration', () => {
       'not specified a service name or version even if GAE_VERSION has ' +
       'been set',
     () => {
-      setEnv(null, 'InvalidVersion', null, 'InvalidVersion', null);
+      setEnv({
+        gaeServiceName: null,
+        gaeServiceVersion: 'InvalidVersion',
+        gaeModuleName: null,
+        gaeModuleVersion: 'InvalidVersion',
+        functionName: null,
+        kService: null,
+        kRevision: null,
+      });
       const c = new Configuration({}, logger);
       assert.strictEqual(c.getServiceContext().service, 'node');
       assert.strictEqual(c.getServiceContext().version, undefined);
@@ -281,4 +347,32 @@ describe('Testing service configuration', () => {
       deepStrictEqual(c.getServiceContext().version, '2.0');
     }
   );
+  it('A Configuration uses the K_SERVICE and K_REVISION env variables if set', () => {
+    setEnv({
+      gaeServiceName: null,
+      gaeServiceVersion: 'x',
+      gaeModuleName: null,
+      gaeModuleVersion: 'y',
+      functionName: null,
+      kService: 'custom-service',
+      kRevision: 'custom-revision',
+    });
+    const c = new Configuration({}, logger);
+    assert.strictEqual(c.getServiceContext().service, 'custom-service');
+    assert.strictEqual(c.getServiceContext().version, 'custom-revision');
+  });
+  it('A Configuration gives priority to K_SERVICE and K_REVISION env variables', () => {
+    setEnv({
+      gaeServiceName: 'gae-service-name',
+      gaeServiceVersion: 'gae-service-version',
+      gaeModuleName: 'gae-module-name',
+      gaeModuleVersion: 'gae-module-version',
+      functionName: 'function-name',
+      kService: 'k-service',
+      kRevision: 'k-revision',
+    });
+    const c = new Configuration({}, logger);
+    assert.strictEqual(c.getServiceContext().service, 'k-service');
+    assert.strictEqual(c.getServiceContext().version, 'k-revision');
+  });
 });