[w3c-trace-context] Update dependencies, align with OTel/DD best prac…

apps/w3c-trace-context/.env.example

@@ -0,0 +1,5 @@
+# Required: Your Datadog API key
+DD_API_KEY=your_api_key_here
+
+# Optional: Datadog site (default: datadoghq.com)
+# DD_SITE=datadoghq.com

apps/w3c-trace-context/Dockerfile.calendar.java.dd

@@ -1,21 +1,27 @@
 # Unless explicitly stated otherwise all files in this repository are licensed
 # under the Apache 2.0 License.
 #
-FROM openjdk:17-buster
+FROM eclipse-temurin:17-jdk AS builder
 
-RUN apt-get update -y; apt-get install curl -y
+RUN apt-get update -y && apt-get install -y --no-install-recommends curl && rm -rf /var/lib/apt/lists/*
 
 WORKDIR /home/otel
+RUN curl -Lo dd-java-agent.jar https://dtdg.co/latest-java-tracer
 
-RUN curl -Lo dd-java-agent.jar https://dtdg.co/latest-java-tracer 
-
-
-COPY java/calendar calendar/  
+COPY java/calendar calendar/
 
 WORKDIR /home/otel/calendar
 
-#Compile with gradle
+# Compile with gradle
 RUN ./gradlew build
 
-ENTRYPOINT ["java","-javaagent:../dd-java-agent.jar",  "-jar" , "build/libs/calendar-0.0.1-SNAPSHOT.jar"]
+FROM eclipse-temurin:17-jre
+
+WORKDIR /app
+COPY --from=builder /home/otel/dd-java-agent.jar /app/dd-java-agent.jar
+COPY --from=builder /home/otel/calendar/build/libs/calendar-0.0.1-SNAPSHOT.jar /app/calendar.jar
+
+STOPSIGNAL SIGTERM
+
+ENTRYPOINT ["java", "-javaagent:/app/dd-java-agent.jar", "-jar", "/app/calendar.jar"]
 EXPOSE 8080

apps/w3c-trace-context/Dockerfile.calendar.java.otel

@@ -1,19 +1,27 @@
 # Unless explicitly stated otherwise all files in this repository are licensed
 # under the Apache 2.0 License.
 #
-FROM openjdk:17-buster
+FROM eclipse-temurin:17-jdk AS builder
 
-RUN apt-get update -y; apt-get install curl -y
+RUN apt-get update -y && apt-get install -y --no-install-recommends curl && rm -rf /var/lib/apt/lists/*
 
 WORKDIR /home/otel
 RUN curl -Lo opentelemetry-javaagent.jar https://github.com/open-telemetry/opentelemetry-java-instrumentation/releases/latest/download/opentelemetry-javaagent.jar
 
-COPY java/calendar calendar/  
+COPY java/calendar calendar/
 
 WORKDIR /home/otel/calendar
 
-#Compile with gradle
+# Compile with gradle
 RUN ./gradlew build
 
-ENTRYPOINT ["java","-javaagent:../opentelemetry-javaagent.jar",  "-jar" , "build/libs/calendar-0.0.1-SNAPSHOT.jar"]
+FROM eclipse-temurin:17-jre
+
+WORKDIR /app
+COPY --from=builder /home/otel/opentelemetry-javaagent.jar /app/opentelemetry-javaagent.jar
+COPY --from=builder /home/otel/calendar/build/libs/calendar-0.0.1-SNAPSHOT.jar /app/calendar.jar
+
+STOPSIGNAL SIGTERM
+
+ENTRYPOINT ["java", "-javaagent:/app/opentelemetry-javaagent.jar", "-jar", "/app/calendar.jar"]
 EXPOSE 8080

apps/w3c-trace-context/Dockerfile.calendar.py.dd

@@ -1,14 +1,15 @@
 # Unless explicitly stated otherwise all files in this repository are dual-licensed
 # under the Apache 2.0 or BSD3 Licenses.
-FROM python:3
-
+FROM python:3.12-slim
 
 WORKDIR /home
 
 COPY py /home/py
 WORKDIR /home/py
 
-RUN pip install -r requirements.txt
+RUN pip install --no-cache-dir -r requirements.txt
+
+STOPSIGNAL SIGTERM
 
-# Run the application with Datadog
-CMD ["ddtrace-run", "python", "-m", "calendar_app.app"] 
+# Run the application with Datadog auto-instrumentation
+CMD ["ddtrace-run", "python", "-m", "calendar_app.app"]

apps/w3c-trace-context/Dockerfile.calendar.py.otel

@@ -1,18 +1,20 @@
 # Unless explicitly stated otherwise all files in this repository are dual-licensed
 # under the Apache 2.0 or BSD3 Licenses.
-FROM python:3
+FROM python:3.12-slim
 
 WORKDIR /home
 
 COPY py /home/py
 WORKDIR /home/py
 
-RUN pip install -r requirements.txt
-RUN pip install opentelemetry-distro
-RUN pip install opentelemetry-instrumentation-flask
-RUN pip install	opentelemetry-exporter-otlp
-RUN pip install opentelemetry-instrumentation-system-metrics
+RUN pip install --no-cache-dir -r requirements.txt && \
+    pip install --no-cache-dir \
+        opentelemetry-distro==0.60b1 \
+        opentelemetry-instrumentation-flask==0.60b1 \
+        opentelemetry-exporter-otlp==1.39.1 \
+        opentelemetry-instrumentation-requests==0.60b1
 
+STOPSIGNAL SIGTERM
 
-# Run the application with OTel
-CMD ["opentelemetry-instrument", "python", "-m", "calendar_app.app"] 
+# Run the application with OTel auto-instrumentation
+CMD ["opentelemetry-instrument", "python", "-m", "calendar_app.app"]

apps/w3c-trace-context/README.md

@@ -1,38 +1,117 @@
-## Calendar Application
+## W3C Trace Context Propagation Example
+
+Demonstrates [W3C Trace Context](https://www.w3.org/TR/trace-context/) propagation
+between OpenTelemetry-instrumented and Datadog-instrumented services. A Java
+(Spring Boot) "frontend" calendar service calls a Python (Flask) "backend"
+calendar service. Both agents -- OTel and Datadog -- inject and extract
+`traceparent` and `tracestate` HTTP headers automatically so that a single
+distributed trace spans both services regardless of which instrumentation
+library each one uses.
+
+### API
+
 ```
-GET /calendar
-Returns a random date in 2022.
+GET /calendar   -> returns a random date in 2022
+GET /health     -> health check endpoint
 ```
 
-Request
-curl 'http://localhost:8080/calendar'
+Request:
+```bash
+curl http://localhost:8080/calendar
+```
 
-Response
+Response:
+```json
 {"date":"3/22/2022"}
+```
 
+### Prerequisites
 
-## Docker Compose
-
-Retrieve API_KEY from datadoghq, and expose same on Shell
+Set your Datadog API key:
 
-```
-export DD_API_KEY=xx
+```bash
+export DD_API_KEY=<your-api-key>
 ```
 
-Bring up java & py services with DD agent. Java service is instrumented with otel, py service is instrumented with datadog
+Optionally copy `.env.example` to `.env` and fill in the values.
 
-```
+### Deployment Modes
+
+The example ships three docker-compose files, each showing a different
+combination of OTel and Datadog instrumentation. All three use the Datadog
+Agent as the backend for both OTLP and DD trace intake.
+
+#### Mode 1 -- OTel Java, DD Python
+
+Java service instrumented with the OTel Java agent sends traces via OTLP.
+Python service instrumented with ddtrace sends traces via the DD trace API.
+W3C `traceparent`/`tracestate` headers link the two.
+
+```bash
 docker compose -f docker-compose-otel-java-dd-py.yaml up
 ```
 
-Bring up java & py services with DD agent. Java service is instrumented with dd-trace, py service is instrumented with otel
+| Service | Port | Instrumentation |
+|---------|------|-----------------|
+| calendar-java-otel | 8080 | OpenTelemetry Java agent |
+| calendar-py-dd | 9090 | ddtrace |
 
-```
+#### Mode 2 -- DD Java, OTel Python
+
+Java service instrumented with dd-java-agent; Python service instrumented
+with the OTel Python SDK. `DD_TRACE_PROPAGATION_STYLE=tracecontext` on the
+Java side ensures W3C headers are emitted.
+
+```bash
 docker compose -f docker-compose-dd-java-otel-py.yaml up
 ```
 
-Bring up two sets of java and py services with DD agent. One set is instrumented with dd-trace, the other set is instrumented with otel
+| Service | Port | Instrumentation |
+|---------|------|-----------------|
+| calendar-java-dd | 8080 | dd-java-agent |
+| calendar-py-otel | 9090 | OpenTelemetry Python |
 
-```
+#### Mode 3 -- Both side by side
+
+Two parallel request chains through a single Datadog Agent, proving
+cross-instrumentation interoperability in both directions.
+
+```bash
 docker compose -f docker-compose-dd-otel-both.yaml up
-```
+```
+
+| Service | Port | Instrumentation |
+|---------|------|-----------------|
+| calendar-java-dd (chain A) | 8080 | dd-java-agent |
+| calendar-py-otel (chain A) | 9091 | OpenTelemetry Python |
+| calendar-java-otel (chain B) | 8081 | OpenTelemetry Java agent |
+| calendar-py-dd (chain B) | 9090 | ddtrace |
+
+### How W3C Trace Context works here
+
+Both the OpenTelemetry agents and the Datadog agents handle `traceparent`
+and `tracestate` injection/extraction automatically:
+
+- **OTel services** use `OTEL_PROPAGATORS=tracecontext,baggage` (the default)
+  to propagate W3C headers.
+- **DD services** use `DD_TRACE_PROPAGATION_STYLE=tracecontext` to switch
+  from the Datadog-native propagation format to W3C Trace Context.
+- **128-bit trace IDs** are enabled on DD services via
+  `DD_TRACE_128_BIT_TRACEID_GENERATION_ENABLED=true` so that trace IDs are
+  compatible with the 32-hex-character trace-id field in the `traceparent`
+  header.
+
+The Datadog Agent accepts both OTLP (ports 4317/4318) and DD APM traces
+(port 8126), correlating them into unified traces in the Datadog UI.
+
+### Configuration reference
+
+| Variable | Used by | Purpose |
+|----------|---------|---------|
+| `DD_API_KEY` | DD Agent | Datadog API key |
+| `DD_SITE` | DD Agent | Datadog site (default `datadoghq.com`) |
+| `DD_TRACE_PROPAGATION_STYLE` | DD services | Set to `tracecontext` for W3C |
+| `DD_TRACE_128_BIT_TRACEID_GENERATION_ENABLED` | DD services | Full 128-bit trace IDs |
+| `OTEL_PROPAGATORS` | OTel services | Propagator chain (`tracecontext,baggage`) |
+| `OTEL_EXPORTER_OTLP_ENDPOINT` | OTel services | OTLP endpoint on the DD Agent |
+| `OTEL_EXPORTER_OTLP_PROTOCOL` | OTel services | `grpc` or `http/protobuf` |

apps/w3c-trace-context/docker-compose-dd-java-otel-py.yaml

@@ -1,9 +1,21 @@
-version: "3.9"
+# Mode 2: DD-instrumented Java service -> OTel-instrumented Python service
+#
+# Demonstrates W3C Trace Context propagation from a Datadog-instrumented
+# Java service to an OpenTelemetry-instrumented Python service. The DD Java
+# agent injects traceparent/tracestate headers (when DD_TRACE_PROPAGATION_STYLE
+# is set to tracecontext); the OTel Python agent extracts them to continue
+# the distributed trace.
+#
+# Usage:
+#   export DD_API_KEY=<your-api-key>
+#   docker compose -f docker-compose-dd-java-otel-py.yaml up
 services:
   calendar-java-dd:
     depends_on:
-      - datadog-agent
-      - calendar-py-otel
+      datadog-agent:
+        condition: service_healthy
+      calendar-py-otel:
+        condition: service_healthy
     container_name: calendar-java-dd
     build:
       context: .
@@ -18,8 +30,23 @@ services:
       - SERVER_PORT=8080
     ports:
       - "8080:8080"
+    healthcheck:
+      test: ["CMD-SHELL", "curl -f http://localhost:8080/health || exit 1"]
+      interval: 10s
+      timeout: 5s
+      retries: 5
+      start_period: 30s
+    deploy:
+      resources:
+        limits:
+          memory: 512M
+          cpus: "1.0"
+    stop_grace_period: 15s
 
   calendar-py-otel:
+    depends_on:
+      datadog-agent:
+        condition: service_healthy
     container_name: calendar-py-otel
     build:
       context: .
@@ -28,12 +55,25 @@ services:
       - OTEL_SERVICE_NAME=calendar-py-otel
       - OTEL_EXPORTER_OTLP_ENDPOINT=http://datadog-agent:4317
       - OTEL_EXPORTER_OTLP_PROTOCOL=grpc
+      - OTEL_PROPAGATORS=tracecontext,baggage
       - OTEL_RESOURCE_ATTRIBUTES=deployment.environment=docker,host.name=otelcol-docker
       - OTEL_TRACES_EXPORTER=otlp
       - OTEL_METRICS_EXPORTER=otlp
       - SERVER_PORT=9090
     ports:
       - "9090:9090"
+    healthcheck:
+      test: ["CMD-SHELL", "curl -f http://localhost:9090/health || exit 1"]
+      interval: 10s
+      timeout: 5s
+      retries: 5
+      start_period: 15s
+    deploy:
+      resources:
+        limits:
+          memory: 256M
+          cpus: "0.5"
+    stop_grace_period: 15s
 
   datadog-agent:
     container_name: datadog-agent
@@ -46,7 +86,7 @@ services:
       - 4318:4318
     environment:
       - DD_API_KEY
-      - DD_SITE=datadoghq.com
+      - DD_SITE=${DD_SITE:-datadoghq.com}
       - DD_APM_NON_LOCAL_TRAFFIC=true
       - DD_DOGSTATSD_NON_LOCAL_TRAFFIC=true
       - DD_OTLP_CONFIG_RECEIVER_PROTOCOLS_GRPC_ENDPOINT=0.0.0.0:4317
@@ -55,3 +95,14 @@ services:
       - /var/run/docker.sock:/var/run/docker.sock
       - /proc/:/host/proc/:ro
       - /sys/fs/cgroup:/host/sys/fs/cgroup:ro
+    healthcheck:
+      test: ["CMD-SHELL", "agent health"]
+      interval: 10s
+      timeout: 5s
+      retries: 5
+      start_period: 15s
+    deploy:
+      resources:
+        limits:
+          memory: 512M
+          cpus: "1.0"