feat: add VM.get/setLabels() methods

src/vm.js

@@ -466,6 +466,44 @@ class VM extends common.ServiceObject {
       });
     });
   }
+  /**
+   * Get the instance's labels and their fingerprint.
+   *
+   * This method wraps {module:compute/vm#getMetadata}, returning only the `labels`
+   * property.
+   *
+   * @param {function} callback - The callback function.
+   * @param {?error} callback.err - An error returned while making this request.
+   * @param {object[]} callback.labels - Label objects from this VM.
+   * @param {string} callback.fingerprint - The current label fingerprint.
+   * @param {object} callback.apiResponse - The full API response.
+   *
+   * @example
+   * const Compute = require('@google-cloud/compute');
+   * const compute = new Compute();
+   * const zone = compute.zone('zone-name');
+   * const vm = zone.vm('vm-name');
+   *
+   * vm.getLabels(function(err, labels, fingerprint, apiResponse) {});
+   *
+   * //-
+   * // If the callback is omitted, we'll return a Promise.
+   * //-
+   * vm.getLabels().then(function(data) {
+   *   const labels = data[0];
+   *   const fingerprint = data[1];
+   *   const apiResponse = data[2];
+   * });
+   */
+  getLabels(callback) {
+    this.getMetadata((err, metadata, apiResponse) => {
+      if (err) {
+        callback(err, null, null, apiResponse);
+        return;
+      }
+      callback(null, metadata.labels, metadata.labelFingerprint, apiResponse);
+    });
+  }
   /**
    * Returns the serial port output for the instance.
    *
@@ -721,6 +759,56 @@ class VM extends common.ServiceObject {
       })
     );
   }
+  /**
+   * Set labels for this instance.
+   *
+   * @see [Instances: setLabels API Documentation]{@link https://cloud.google.com/compute/docs/reference/v1/instances/setLabels}
+   *
+   * @param {object} labels - New labels.
+   * @param {function=} callback - The callback function.
+   * @param {?error} callback.err - An error returned while making this request.
+   * @param {Operation} callback.operation - An operation object
+   *     that can be used to check the status of the request.
+   * @param {object} callback.apiResponse - The full API response.
+   *
+   * @example
+   * const Compute = require('@google-cloud/compute');
+   * const compute = new Compute();
+   * const zone = compute.zone('zone-name');
+   * const vm = zone.vm('vm-name');
+   *
+   * const labels = {
+   *   'startup-script': '...',
+   *   customKey: null // Setting `null` will remove the `customKey` property.
+   * };
+   *
+   * vm.setLabels(labels, function(err, operation, apiResponse) {
+   *   // `operation` is an Operation object that can be used to check the status
+   *   // of the request.
+   * });
+   *
+   * //-
+   * // If the callback is omitted, we'll return a Promise.
+   * //-
+   * vm.setLabels(labels).then(function(data) {
+   *   const operation = data[0];
+   *   const apiResponse = data[1];
+   * });
+   */
+  setLabels(labels, labelFingerprint, callback) {
+    const body = {
+      labels: labels,
+      labelFingerprint: labelFingerprint,
+    };
+    this.request(
+      {
+        method: 'POST',
+        uri: '/setLabels',
+        json: body,
+      },
+      callback || common.util.noop
+    );
+  }
   /**
    * Set the custom metadata for this instance.
    *

system-test/compute.js

@@ -979,6 +979,13 @@ describe('Compute', () => {
       return vm.getSerialPortOutput();
     });
 
+    it('should set labels', async () => {
+      let [labels, fingerprint] = await vm.getLabels();
+      await awaitResult(vm.setLabels({foo: 'bar'}, fingerprint));
+      [labels, fingerprint] = await vm.getLabels();
+      assert.strictEqual(labels.foo, 'bar');
+    });
+
     it('should set tags', async () => {
       const newTagName = 'new-tag';
       const [tags, fingerprint] = await vm.getTags();

test/vm.js

@@ -383,6 +383,65 @@ describe('VM', () => {
     });
   });
 
+  describe('getLabels', () => {
+    it('should get metadata', done => {
+      vm.getMetadata = function () {
+        done();
+      };
+
+      vm.getTags(assert.ifError);
+    });
+
+    describe('error', () => {
+      const error = new Error('Error.');
+      const apiResponse = {a: 'b', c: 'd'};
+
+      beforeEach(() => {
+        vm.getMetadata = function (callback) {
+          callback(error, null, apiResponse);
+        };
+      });
+
+      it('should execute callback with error', done => {
+        vm.getLabels((err, labels, fingerprint, apiResponse_) => {
+          assert.strictEqual(err, error);
+          assert.strictEqual(labels, null);
+          assert.strictEqual(fingerprint, null);
+          assert.strictEqual(apiResponse_, apiResponse);
+
+          done();
+        });
+      });
+    });
+
+    describe('success', () => {
+      const metadata = {
+        labels: {},
+        labelFingerprint: 'fingerprint',
+      };
+
+      const apiResponse = {a: 'b', c: 'd'};
+
+      beforeEach(() => {
+        vm.getMetadata = function (callback) {
+          callback(null, metadata, apiResponse);
+        };
+      });
+
+      it('should execute callback with tags and fingerprint', done => {
+        vm.getLabels((err, labels, fingerprint, apiResponse_) => {
+          assert.ifError(err);
+
+          assert.strictEqual(labels, metadata.labels);
+          assert.strictEqual(fingerprint, metadata.labelFingerprint);
+          assert.strictEqual(apiResponse_, apiResponse);
+
+          done();
+        });
+      });
+    });
+  });
+
   describe('getSerialPortOutput', () => {
     const EXPECTED_QUERY = {port: 1, start: 0};
 
@@ -738,6 +797,33 @@ describe('VM', () => {
     });
   });
 
+  describe('setLabels', () => {
+    const LABELS = [];
+    const FINGERPRINT = '';
+
+    it('should make the correct request', done => {
+      vm.request = function (reqOpts, callback) {
+        assert.strictEqual(reqOpts.method, 'POST');
+        assert.strictEqual(reqOpts.uri, '/setLabels');
+        assert.strictEqual(reqOpts.json.labels, LABELS);
+        assert.strictEqual(reqOpts.json.labelFingerprint, FINGERPRINT);
+
+        callback(); // done()
+      };
+
+      vm.setLabels(LABELS, FINGERPRINT, done);
+    });
+
+    it('should not require a callback', done => {
+      vm.request = function (reqOpts, callback) {
+        assert.doesNotThrow(callback);
+        done();
+      };
+
+      vm.setLabels(LABELS, FINGERPRINT);
+    });
+  });
+
   describe('setMetadata', () => {
     const METADATA = {
       newKey: 'newValue',