Add w3c trace context propagation example

README.md

@@ -21,6 +21,7 @@ The repository includes example applications and configurations for Datadog user
 | [Span Links][12] | Distributed app with Kafka messages, OTel Go and Java instrumentations | OTel span links |
 | [W3C Trace Context][13] | Java and Python app to demonstrate W3C trace context propagation between OTel and DD instrumented apps | W3C trace context, runtime metrics |
 | [Kubernetes (Datadog Operator and Helm) with Express][15] | An Express sample app configured with Kubernetes  | Kubernetes |
+| [Python and Javascript trace context propagation][17] | An Express controller server calling two Flask servers | Standalone Host |
 
 
 [1]: https://opentelemetry.io/
@@ -35,7 +36,8 @@ The repository includes example applications and configurations for Datadog user
 [10]: ./apps/rest-services/py/
 [11]: ./apps/rpc/
 [12]: ./apps/span-links/
-[13]: ./apps/w3-trace-context/
+[13]: ./apps/w3c-trace-context/
 [14]: ./guides/common-mistakes.md
 [15]: ./configurations/
-[16]: ./apps/kubernetes-express-otel/
+[16]: ./apps/kubernetes-express-otel/
+[17]: ./apps/w3c-trace-context-ex2/

apps/rolldice-game/README.md

@@ -0,0 +1,32 @@
+# W3C Trace Context Example
+This project consists of two Flask servers and one Express server instrumented with Opentelemetry on a standalone host. (This is not using k8s or containers)
+
+## Start the Demo
+### Option 1 (Standalone Host)
+There are a few required steps to get this example working. 
+1. Install and set up the OpenTelemetry Collector on the host of your choice. https://opentelemetry.io/docs/collector/installation/
+2. Set up the Collector configuration. An example collector configuration can be found at [Config File](./config.yaml).
+    * The config.yaml is set up to send traces and metrics from OTLP Collector to the Datadog Exporter.
+    * Update the DATADOG_API_KEY as well.
+3. Run this collector  ~ `./otelcol-contrib --config=config.yaml`
+4. Once the collector is up and running. Set up the 3 servers. (Can be found in each of the servers README)
+
+### Option 2 (Docker)
+1. Update DATADOG_API_KEY in [Config File](./config.yaml).
+2. Run docker-compose up
+
+To trigger the service call
+
+### Success
+```bash
+curl -X POST http://localhost:5002/play_game \
+     -H "Content-Type: application/json" \
+     -d '{"player": "John Doe"}'
+```
+### Error
+``` bash
+curl -X POST http://localhost:5002/play_game \
+     -H "Content-Type: application/json" \
+     -d '{}'
+```
+View traces & standalone host in app.datadoghq.com

apps/rolldice-game/config.yml

@@ -0,0 +1,44 @@
+receivers:
+  otlp:
+    protocols:
+      grpc:
+        endpoint: 0.0.0.0:4317
+      http:
+        endpoint: 0.0.0.0:4318
+  hostmetrics:
+    # collect metrics every 10 seconds.
+    collection_interval: 10s
+    scrapers:
+      cpu:
+      disk:
+      filesystem:
+      memory:
+      network:
+      load:
+      paging:
+      processes:
+
+exporters:
+  # NOTE: Prior to v0.86.0 use `logging` instead of `debug`.
+  debug:
+    verbosity: detailed
+  datadog/exporter:
+    api:
+      site: datadoghq.com
+      key: <DATADOG_API_KEY>
+
+processors:
+  batch:
+connectors:
+  datadog/connector:
+service:
+  pipelines:
+    traces:
+      receivers: [otlp]
+      processors: [batch]
+      exporters: [datadog/connector, datadog/exporter]
+    metrics:
+      receivers: [datadog/connector, otlp]
+      processors: [batch]
+      exporters: [datadog/exporter]
+

apps/rolldice-game/docker-compose.yml

@@ -0,0 +1,66 @@
+version: '3'
+services:
+  game_controller:
+    build:
+      context: ./game_controller
+      dockerfile: Dockerfile
+    ports:
+      - "5002:5002"
+    depends_on:
+      otelcol:
+        condition: service_started
+      rolling:
+        condition: service_started
+      scoring:
+        condition: service_started
+    environment:
+      - OTEL_SERVICE_NAME=controller
+      - OTEL_EXPORTER_OTLP_ENDPOINT=http://otelcol:4317
+
+
+  rolling:
+    build:
+      context: ./rolling
+      dockerfile: Dockerfile
+    ports:
+      - "5004:5004"
+    depends_on:
+      otelcol:
+        condition: service_started
+    environment:
+      - OTEL_SERVICE_NAME=rolly
+      - OTEL_EXPORTER_OTLP_ENDPOINT=http://otelcol:4317
+
+
+  scoring:
+    build:
+      context: ./scoring
+      dockerfile: Dockerfile
+    ports:
+      - "5001:5001"
+    depends_on:
+      otelcol:
+        condition: service_started
+    environment:
+      - OTEL_SERVICE_NAME=scorey
+      - OTEL_EXPORTER_OTLP_ENDPOINT=http://otelcol:4317
+
+
+  otelcol:
+    image: otel/opentelemetry-collector-contrib
+    deploy:
+      resources:
+        limits:
+          memory: 200M
+    restart: unless-stopped
+    command: [ "--config=/etc/otelcol-config.yml"]
+    volumes:
+      - ./config.yml:/etc/otelcol-config.yml
+    ports:
+      - "4318:4318" # OTLP http receiver
+      - "4317:4317"
+    environment:
+      - DD_OTLP_CONFIG_RECEIVER_PROTOCOLS_GRPC_ENDPOINT=0.0.0.0:4317
+      - DD_OTLP_CONFIG_RECEIVER_PROTOCOLS_HTTP_ENDPOINT=0.0.0.0:4318
+
+

apps/rolldice-game/game_controller/Dockerfile

@@ -0,0 +1,23 @@
+# Use an official Node.js runtime as the base image
+FROM node:14-alpine
+
+# Set the working directory
+WORKDIR /game_controller
+
+# Copy the project files to the working directory
+COPY . ./game_controller
+COPY package*.json ./game_controller/
+
+WORKDIR /game_controller
+
+# Install the project dependencies
+RUN npm install
+ENV service_name=controller
+ENV logs_exporter=otlp
+
+
+# Expose port 5002 for the app to be accessible
+EXPOSE 5002
+
+# Define the command to run the app
+CMD [ "node", "game_controller/controller.js" ]

apps/rolldice-game/game_controller/README.md

@@ -0,0 +1,19 @@
+# Game Controller
+This project is a simple Express.js application that uses the OpenTelemetry API for tracing and axios for HTTP requests.
+
+
+## Installation
+* Node.js (v12 or later)
+* npm (v6 or later)
+
+
+```bash
+npm install
+```
+
+## Run the server
+
+```bash
+opentelemetry-instrument --service_name controller --logs_exporter otlp node controller.js
+```
+

apps/rolldice-game/game_controller/controller.js

@@ -0,0 +1,47 @@
+const express = require('express');
+const axios = require('axios');
+const { context, trace, propagation } = require('@opentelemetry/api');
+const { NodeSDK } = require('@opentelemetry/sdk-node');
+const { getNodeAutoInstrumentations } = require('@opentelemetry/auto-instrumentations-node');
+
+const sdk = new NodeSDK({
+  instrumentations: [getNodeAutoInstrumentations()],
+});
+
+sdk.start();
+const app = express();
+app.use(express.json());
+
+app.post('/play_game', async (req, res) => {
+  const tracer = trace.getTracer('express-game-controller');
+  const span = tracer.startSpan('play_game');
+
+  const ctx = trace.setSpan(context.active(), span);
+
+  context.with(ctx, async () => {
+    try {
+      const player = req.body.player;
+      const headers = {};
+      propagation.inject(context.active(), headers);
+      const diceRollResult = await axios.get(`http://rolling:5004/rolldice?player=${player}`, { headers });
+      const updateScoreResult = await axios.post('http://scoring:5001/update_score', {
+        player: player,
+        result: diceRollResult.data
+      }, { headers });
+
+      span.addEvent('score_updated');
+      span.end();
+      res.json(updateScoreResult.data);
+    } catch (error) {
+      span.recordException(error);
+      span.end();
+      console.error(error);
+      res.status(500).send('An error occurred');
+    }
+  });
+});
+
+const PORT = process.env.PORT || 5002;
+app.listen(PORT, () => {
+  console.log(`Game Controller service listening at http://localhost:${PORT}`);
+});