Experimental support for grpc tracing

Fixes #226

lib/hooks/index.js

@@ -39,6 +39,8 @@ var fs = require('fs');
 var toInstrument = Object.create(null, {
   'express': { enumerable: true, value: { file: './userspace/hook-express.js',
       patches: {} } },
+  'grpc': { enumerable: true, value: { file: './userspace/hook-grpc.js',
+      patches: {} } },
   'hapi': { enumerable: true, value: { file: './userspace/hook-hapi.js',
       patches: {} } },
   'http': { enumerable: true, value: { file: './core/hook-http.js',

lib/hooks/userspace/hook-grpc.js

@@ -0,0 +1,50 @@
+/**
+ * Copyright 2015 Google Inc. All Rights Reserved.
+ *
+ * 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.
+ */
+
+'use strict';
+
+var cls = require('../../cls.js');
+var shimmer = require('shimmer');
+var semver = require('semver');
+var agent;
+
+var SUPPORTED_VERSIONS = '0.13.x';
+
+function startBatchWrap(startBatch) {
+  return function startBatchTrace(thing, callback) {
+    console.log(arguments);
+    // TODO: maybe we only want to do this if a root context exists.
+    return startBatch.call(this, thing, cls.getNamespace().bind(callback));
+  };
+}
+
+module.exports = function(version_, agent_) {
+  if (!semver.satisfies(version_, SUPPORTED_VERSIONS)) {
+    agent_.logger.info('grpc: unsupported version ' + version_ + ' loaded');
+    return {};
+  }
+  return {
+    'src/node/src/grpc_extension.js': {
+      patch: function(extension) {
+        agent = agent_;
+        shimmer.wrap(extension.Call.prototype, 'startBatch', startBatchWrap);
+      },
+      unpatch: function(extension) {
+        shimmer.unwrap(extension.Call.prototype, 'startBatch');
+      }
+    }
+  };
+};

test/fixtures/test.proto

@@ -0,0 +1,15 @@
+syntax = "proto3";
+
+package nodetest;
+
+service Tester {
+  rpc Test (TestRequest) returns (TestReply) {}
+}
+
+message TestRequest {
+  string message = 1;
+}
+
+message TestReply {
+  string message = 1;
+}

test/hooks/fixtures/grpc0.13/index.js

@@ -0,0 +1 @@
+module.exports = require('grpc');

test/hooks/fixtures/grpc0.13/package.json

@@ -0,0 +1,8 @@
+{
+  "name": "grpc0.13",
+  "version": "1.0.0",
+  "main": "index.js",
+  "dependencies": {
+    "grpc": "^0.13.1"
+  }
+}

test/standalone/test-grpc-context.js

@@ -0,0 +1,69 @@
+/**
+ * Copyright 2015 Google Inc. All Rights Reserved.
+ *
+ * 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.
+ */
+'use strict';
+
+var agent = require('../..').start({ samplingRate: 0 }).private_();
+
+var common = require('../hooks/common.js');
+
+var assert = require('assert');
+var express = require('../hooks/fixtures/express4');
+var http = require('http');
+var grpc = require('../hooks/fixtures/grpc0.13');
+var test_proto = grpc.load(__dirname + '/../fixtures/test.proto').nodetest;
+var grcPort = 50051;
+var debugCount = 0;
+agent.logger.debug = function(error) {
+  if (error.indexOf('http') !== -1) {
+    debugCount++;
+  }
+};
+
+describe('express + grpc', function() {
+  it('grpc should preserve context', function(done) {
+    var app = express();
+    app.get('/', function (req, res) {
+      var client = new test_proto.Tester('localhost:' + grcPort,
+        grpc.credentials.createInsecure());
+      client.test({message: 'hello'}, function(err, grpcRes) {
+        http.get('http://www.google.com/', function(httpRes) {
+          httpRes.on('data', function() {});
+          httpRes.on('end', function() {
+            res.sendStatus(200);
+          });
+        });
+      });
+    });
+    var server = app.listen(common.serverPort, function() {
+      var grpcServer = new grpc.Server();
+      grpcServer.addProtoService(test_proto.Tester.service, {
+        test: function(call, cb) {
+          cb(null, {message: 'world'});
+        }
+      });
+      grpcServer.bind('localhost:' + grcPort,
+        grpc.ServerCredentials.createInsecure());
+      grpcServer.start();
+      http.get({port: common.serverPort}, function(res) {
+        grpcServer.forceShutdown();
+        server.close();
+        assert.equal(common.getTraces().length, 1);
+        assert.equal(debugCount, 1);
+        done();
+      });
+    });
+  });
+});