Split dice example into instrumented and uninstrumented (#6300)

As discussed in this thread, we want to have two different examples, one
with instrumentation and one without it.

Fixes
#6296

---------

Signed-off-by: Igor Eulalio <[email protected]>
Co-authored-by: Robert Pająk <[email protected]>

.gitignore

@@ -12,7 +12,8 @@ coverage.*
 go.work
 go.work.sum
 
-examples/dice/dice
+examples/dice/instrumented/instrumented
+examples/dice/uninstrumented/uninstrumented
 examples/namedtracer/namedtracer
 examples/otel-collector/otel-collector
 examples/opencensus/opencensus

examples/dice/README.md

@@ -0,0 +1,32 @@
+# Dice example
+
+This is the foundation example for [Getting Started](https://opentelemetry.io/docs/languages/go/getting-started/) with OpenTelemetry.
+
+Below, you will see instructions on how to run this application, either with or without instrumentation.
+
+## Usage
+
+The `run.sh` script accepts one argument to determine which example to run:
+
+- `uninstrumented`
+- `instrumented`
+
+### Running the Uninstrumented Example
+
+The uninstrumented example is a very simple dice application, without OpenTelemetry instrumentation.
+
+To run the uninstrumented example, execute:
+
+```bash
+./run.sh uninstrumented
+```
+
+### Running the Instrumented Example
+
+The instrumented example is exactly the same application, which includes OpenTelemetry instrumentation. 
+
+To run the instrumented example, execute:
+
+```bash
+./run.sh instrumented
+```

examples/dice/instrumented/get.sh

@@ -0,0 +1,17 @@
+# Copyright The OpenTelemetry Authors
+# SPDX-License-Identifier: Apache-2.0
+
+#!/bin/bash
+
+go get "go.opentelemetry.io/otel" \
+  "go.opentelemetry.io/otel/exporters/stdout/stdoutmetric" \
+  "go.opentelemetry.io/otel/exporters/stdout/stdouttrace" \
+  "go.opentelemetry.io/otel/exporters/stdout/stdoutlog" \
+  "go.opentelemetry.io/otel/sdk/log" \
+  "go.opentelemetry.io/otel/log/global" \
+  "go.opentelemetry.io/otel/propagation" \
+  "go.opentelemetry.io/otel/sdk/metric" \
+  "go.opentelemetry.io/otel/sdk/resource" \
+  "go.opentelemetry.io/otel/sdk/trace" \
+  "go.opentelemetry.io/contrib/instrumentation/net/http/otelhttp"\
+  "go.opentelemetry.io/contrib/bridges/otelslog"

examples/dice/go.mod → examples/dice/instrumented/go.mod

@@ -1,4 +1,4 @@
-module go.opentelemetry.io/contrib/examples/dice
+module go.opentelemetry.io/contrib/examples/dice/instrumented
 
 go 1.22
 
@@ -26,6 +26,6 @@ require (
 )
 
 replace (
-	go.opentelemetry.io/contrib/bridges/otelslog => ../../bridges/otelslog
-	go.opentelemetry.io/contrib/instrumentation/net/http/otelhttp => ../../instrumentation/net/http/otelhttp
+	go.opentelemetry.io/contrib/bridges/otelslog => ../../../bridges/otelslog
+	go.opentelemetry.io/contrib/instrumentation/net/http/otelhttp => ../../../instrumentation/net/http/otelhttp
 )

examples/dice/instrumented/init.sh

@@ -0,0 +1,6 @@
+# Copyright The OpenTelemetry Authors
+# SPDX-License-Identifier: Apache-2.0
+
+#!/bin/bash
+
+go mod init go.opentelemetry.io/contrib/examples/dice/instrumented

examples/dice/instrumented/run.sh

@@ -0,0 +1,8 @@
+# Copyright The OpenTelemetry Authors
+# SPDX-License-Identifier: Apache-2.0
+
+#!/bin/bash
+
+go mod tidy
+export OTEL_RESOURCE_ATTRIBUTES="service.name=dice,service.version=0.1.0"
+go run .

examples/dice/instrumented/tidy.sh

@@ -0,0 +1,6 @@
+# Copyright The OpenTelemetry Authors
+# SPDX-License-Identifier: Apache-2.0
+
+#!/bin/bash
+
+go mod tidy

examples/dice/run.sh

@@ -0,0 +1,29 @@
+# Copyright The OpenTelemetry Authors
+# SPDX-License-Identifier: Apache-2.0
+
+#!/bin/bash
+
+# Check if at least one argument is provided
+if [ -z "$1" ]; then
+  echo "Usage: $0 {instrumented|uninstrumented}"
+  exit 1
+fi
+
+# Switch based on the first argument
+case "$1" in
+  instrumented)
+    echo "Running instrumented example..."
+    cd instrumented || exit
+    source tidy.sh
+    source run.sh
+    ;;
+  uninstrumented)
+    echo "Running uninstrumented example..."
+    cd uninstrumented || exit
+    source run.sh
+    ;;
+  *)
+    echo "Invalid argument: $1. Use 'instrumented' or 'uninstrumented'."
+    exit 1
+    ;;
+esac

examples/dice/uninstrumented/go.mod

@@ -0,0 +1,3 @@
+module go.opentelemetry.io/otel/example/dice/uninstrumented
+
+go 1.22

examples/dice/uninstrumented/main.go

@@ -0,0 +1,65 @@
+// Copyright The OpenTelemetry Authors
+// SPDX-License-Identifier: Apache-2.0
+
+package main
+
+import (
+	"context"
+	"log"
+	"net"
+	"net/http"
+	"os"
+	"os/signal"
+	"time"
+)
+
+func main() {
+	if err := run(); err != nil {
+		log.Fatalln(err)
+	}
+}
+
+func run() (err error) {
+	// Handle SIGINT (CTRL+C) gracefully.
+	ctx, stop := signal.NotifyContext(context.Background(), os.Interrupt)
+	defer stop()
+
+	// Start HTTP server.
+	srv := &http.Server{
+		Addr:         ":8080",
+		BaseContext:  func(_ net.Listener) context.Context { return ctx },
+		ReadTimeout:  time.Second,
+		WriteTimeout: 10 * time.Second,
+		Handler:      newHTTPHandler(),
+	}
+	srvErr := make(chan error, 1)
+	go func() {
+		log.Println("Running HTTP server...")
+		srvErr <- srv.ListenAndServe()
+	}()
+
+	// Wait for interruption.
+	select {
+	case err = <-srvErr:
+		// Error when starting HTTP server.
+		return
+	case <-ctx.Done():
+		// Wait for first CTRL+C.
+		// Stop receiving signal notifications as soon as possible.
+		stop()
+	}
+
+	// When Shutdown is called, ListenAndServe immediately returns ErrServerClosed.
+	err = srv.Shutdown(context.Background())
+	return
+}
+
+func newHTTPHandler() http.Handler {
+	mux := http.NewServeMux()
+
+	// Register handlers.
+	mux.HandleFunc("/rolldice/", rolldice)
+	mux.HandleFunc("/rolldice/{player}", rolldice)
+
+	return mux
+}

examples/dice/uninstrumented/rolldice.go

@@ -0,0 +1,29 @@
+// Copyright The OpenTelemetry Authors
+// SPDX-License-Identifier: Apache-2.0
+
+package main
+
+import (
+	"io"
+	"log"
+	"math/rand"
+	"net/http"
+	"strconv"
+)
+
+func rolldice(w http.ResponseWriter, r *http.Request) {
+	roll := 1 + rand.Intn(6) //nolint:gosec // G404: Use of weak random number generator (math/rand instead of crypto/rand) is ignored as this is not security-sensitive.
+
+	var msg string
+	if player := r.PathValue("player"); player != "" {
+		msg = player + " is rolling the dice"
+	} else {
+		msg = "Anonymous player is rolling the dice"
+	}
+	log.Printf("%s, result: %d", msg, roll)
+
+	resp := strconv.Itoa(roll) + "\n"
+	if _, err := io.WriteString(w, resp); err != nil {
+		log.Printf("Write failed: %v", err)
+	}
+}

examples/dice/uninstrumented/run.sh

@@ -0,0 +1,6 @@
+# Copyright The OpenTelemetry Authors
+# SPDX-License-Identifier: Apache-2.0
+
+#!/bin/bash
+
+go run .