gRPC example using proto-loader (#385)

* chore: gRPC example using proto-loader

* chore: gRPC example using proto-loader

* fix: review comments

* fix: we use latest OT package versions

Author: mayurkale22

examples/grpc_dynamic_codegen/README.md

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+# Overview
+
+Our service takes in a payload containing bytes and capitalizes them.
+
+Using OpenTelemetry gRPC Instrumentation, we can collect traces of our system and export them to the backend of our choice (we can use Zipkin or Jaeger for this example), to give observability to our distributed systems.
+
+> This is the dynamic code generation variant of the gRPC examples. Code in these examples is generated at runtime using Protobuf.js.
+
+## Installation
+
+```sh
+$ # from this directory
+$ npm install
+```
+
+Setup [Zipkin Tracing](https://zipkin.io/pages/quickstart.html)
+or
+Setup [Jaeger Tracing](https://www.jaegertracing.io/docs/latest/getting-started/#all-in-one)
+
+## Run the Application
+
+### Zipkin
+
+ - Run the server
+
+   ```sh
+   $ # from this directory
+   $ npm run zipkin:server
+   ```
+
+ - Run the client
+
+   ```sh
+   $ # from this directory
+   $ npm run zipkin:client
+   ```
+
+### Jaeger
+
+ - Run the server
+
+   ```sh
+   $ # from this directory
+   $ npm run jaeger:server
+   ```
+
+ - Run the client
+
+   ```sh
+   $ # from this directory
+   $ npm run jaeger:client
+   ```
+
+## Useful links
+- For more information on OpenTelemetry, visit: <https://opentelemetry.io/>
+- For more information on OpenTelemetry for Node.js, visit: <https://github.com/open-telemetry/opentelemetry-js/tree/master/packages/opentelemetry-node-sdk>
+
+## LICENSE
+
+Apache License 2.0

examples/grpc_dynamic_codegen/capitalize_client.js

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+'use strict';
+
+const opentelemetry = require('@opentelemetry/core');
+const config = require('./setup');
+
+/**
+ * The trace instance needs to be initialized first, if you want to enable
+ * automatic tracing for built-in plugins (gRPC in this case).
+ */
+config.setupTracerAndExporters('grpc-client-service');
+
+const path = require('path');
+const grpc = require('grpc');
+const protoLoader = require('@grpc/proto-loader');
+
+const tracer = opentelemetry.getTracer();
+
+const PROTO_PATH = path.join(__dirname, 'protos/defs.proto');
+const PROTO_OPTIONS = { keepCase: true, enums: String, defaults: true, oneofs: true };
+const definition = protoLoader.loadSync(PROTO_PATH, PROTO_OPTIONS);
+const rpcProto = grpc.loadPackageDefinition(definition).rpc;
+
+function main() {
+  const client = new rpcProto.Fetch('localhost:50051',
+    grpc.credentials.createInsecure());
+  const data = process.argv[2] || 'opentelemetry';
+  console.log('> ', data);
+
+  const span = tracer.startSpan('tutorialsClient.capitalize');
+  tracer.withSpan(span, () => {
+    client.capitalize({ data: Buffer.from(data) }, function (err, response) {
+      if (err) {
+        console.log('could not get grpc response');
+        return;
+      }
+      console.log('< ', response.data.toString('utf8'));
+      // display traceid in the terminal
+      console.log(`traceid: ${span.context().traceId}`);
+      span.end();
+    });
+  });
+
+  // The process must live for at least the interval past any traces that
+  // must be exported, or some risk being lost if they are recorded after the
+  // last export.
+  console.log('Sleeping 5 seconds before shutdown to ensure all records are flushed.')
+  setTimeout(() => { console.log('Completed.'); }, 5000);
+}
+
+main();

examples/grpc_dynamic_codegen/capitalize_server.js

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+'use strict';
+
+const { SpanKind } = require('@opentelemetry/types');
+const opentelemetry = require('@opentelemetry/core');
+
+/**
+ * The trace instance needs to be initialized first, if you want to enable
+ * automatic tracing for built-in plugins (gRPC in this case).
+ */
+const config = require('./setup');
+config.setupTracerAndExporters('grpc-server-service');
+
+const path = require('path');
+const grpc = require('grpc');
+const protoLoader = require('@grpc/proto-loader');
+
+const PROTO_PATH = path.join(__dirname, 'protos/defs.proto');
+const PROTO_OPTIONS = { keepCase: true, enums: String, defaults: true, oneofs: true };
+const definition = protoLoader.loadSync(PROTO_PATH, PROTO_OPTIONS);
+const rpcProto = grpc.loadPackageDefinition(definition).rpc;
+
+const tracer = opentelemetry.getTracer();
+
+/** Implements the Capitalize RPC method. */
+function capitalize(call, callback) {
+  const currentSpan = tracer.getCurrentSpan();
+  // display traceid in the terminal
+  console.log(`traceid: ${currentSpan.context().traceId}`);
+
+  const span = tracer.startSpan('tutorials.FetchImpl.capitalize', {
+    parent: currentSpan,
+    kind: SpanKind.SERVER,
+  });
+
+  const data = call.request.data.toString('utf8');
+  const capitalized = data.toUpperCase();
+  for (let i = 0; i < 100000000; i++) {}
+  span.end();
+  callback(null, { data: Buffer.from(capitalized) });
+}
+
+/**
+ * Starts an RPC server that receives requests for the Fetch service at the
+ * sample server port.
+ */
+function main() {
+  const server = new grpc.Server();
+  server.addService(rpcProto.Fetch.service, { capitalize: capitalize });
+  server.bind('0.0.0.0:50051', grpc.ServerCredentials.createInsecure());
+  server.start();
+}
+
+main();

examples/grpc_dynamic_codegen/package.json

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+{
+  "name": "grpc-dynamic-codegen-example",
+  "version": "0.1.1",
+  "description": "Example of gRPC integration with OpenTelemetry",
+  "main": "index.js",
+  "scripts": {
+    "zipkin:server": "cross-env EXPORTER=zipkin node ./capitalize_server.js",
+    "zipkin:client": "cross-env EXPORTER=zipkin node ./capitalize_client.js",
+    "jaeger:server": "cross-env EXPORTER=jaeger node ./capitalize_server.js",
+    "jaeger:client": "cross-env EXPORTER=jaeger node ./capitalize_client.js"
+  },
+  "repository": {
+    "type": "git",
+    "url": "git+ssh://[email protected]/open-telemetry/opentelemetry-js.git"
+  },
+  "keywords": [
+    "opentelemetry",
+    "grpc",
+    "tracing"
+  ],
+  "engines": {
+    "node": ">=8"
+  },
+  "author": "OpenTelemetry Authors",
+  "license": "Apache-2.0",
+  "bugs": {
+    "url": "https://github.com/open-telemetry/opentelemetry-js/issues"
+  },
+  "dependencies": {
+    "@grpc/proto-loader": "^0.4.0",
+    "@opentelemetry/tracing": "^0.1.1",
+    "@opentelemetry/types": "^0.1.1",
+    "@opentelemetry/core": "^0.1.1",
+    "@opentelemetry/exporter-jaeger": "^0.1.1",
+    "@opentelemetry/exporter-zipkin": "^0.1.1",
+    "@opentelemetry/node": "^0.1.1",
+    "@opentelemetry/plugin-grpc": "^0.1.1",
+    "grpc": "^1.23.3",
+    "node-pre-gyp": "0.12.0"
+  },
+  "homepage": "https://github.com/open-telemetry/opentelemetry-js#readme",
+  "devDependencies": {
+    "cross-env": "^6.0.0"
+  }
+}

examples/grpc_dynamic_codegen/protos/defs.proto

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+syntax = "proto3";
+
+option java_multiple_files = true;
+option java_package = "io.grpc.examples.helloworld";
+option java_outer_classname = "HelloWorldProto";
+option objc_class_prefix = "HLW";
+
+package rpc;
+
+service Fetch {
+  // Sends a capitalizes payload
+  rpc Capitalize(Payload) returns (Payload) {}
+}
+
+// The request and response payload containing the id and data.
+message Payload {
+  int32 id    = 1;
+  bytes data  = 2;
+}

examples/grpc_dynamic_codegen/setup.js

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+'use strict';
+
+const opentelemetry = require('@opentelemetry/core');
+const { NodeTracer } = require('@opentelemetry/node');
+const { SimpleSpanProcessor } = require('@opentelemetry/tracing');
+const { JaegerExporter } = require('@opentelemetry/exporter-jaeger');
+const { ZipkinExporter } = require('@opentelemetry/exporter-zipkin');
+const EXPORTER = process.env.EXPORTER || '';
+
+function setupTracerAndExporters(service) {
+  const tracer = new NodeTracer({
+    plugins: {
+      grpc: {
+        enabled: true,
+        // You may use a package name or absolute path to the file.
+        path: '@opentelemetry/plugin-grpc'
+      }
+    }
+  });
+
+  let exporter;
+  if (EXPORTER.toLowerCase().startsWith('z')) {
+    exporter = new ZipkinExporter({
+      serviceName: service,
+    });
+  } else {
+    exporter = new JaegerExporter({
+      serviceName: service,
+      // The default flush interval is 5 seconds.
+      flushInterval: 2000
+    });
+  }
+
+  // It is recommended to use this `BatchSpanProcessor` for better performance
+  // and optimization, especially in production.
+  tracer.addSpanProcessor(new SimpleSpanProcessor(exporter));
+
+  // Initialize the OpenTelemetry APIs to use the BasicTracer bindings
+  opentelemetry.initGlobalTracer(tracer);
+}
+
+exports.setupTracerAndExporters = setupTracerAndExporters;