From 8dfe488cdf79076f2f7762aa867abcba2de0658a Mon Sep 17 00:00:00 2001
From: Zach <3724288+zedkipp@users.noreply.github.com>
Date: Fri, 6 Feb 2026 16:55:33 -0700
Subject: [PATCH] feat: add mock telemetry server for local development
 (#21932)

Adds a standalone command that acts as a mock telemetry server,
receiving snapshots and printing them as a JSON stream to stdout. Useful
for local development testing with scripts/develop.sh by setting
CODER_TELEMETRY_ENABLE and CODER_TELEMETRY_URL environment variabless.
---
 codersdk/deployment.go           |  2 +
 scripts/telemetry-server/main.go | 74 ++++++++++++++++++++++++++++++++
 2 files changed, 76 insertions(+)
 create mode 100644 scripts/telemetry-server/main.go

diff --git a/codersdk/deployment.go b/codersdk/deployment.go
index 6b450058e6..c7c60ae1db 100644
--- a/codersdk/deployment.go
+++ b/codersdk/deployment.go
@@ -2380,6 +2380,8 @@ func (c *DeploymentValues) Options() serpent.OptionSet {
 			Group:      &deploymentGroupTelemetry,
 			UseInstead: []serpent.Option{telemetryEnable},
 		},
+		// For local development testing, see scripts/telemetry-server which
+		// provides a mock server that prints received telemetry as JSON.
 		{
 			Name:        "Telemetry URL",
 			Description: "URL to send telemetry.",
diff --git a/scripts/telemetry-server/main.go b/scripts/telemetry-server/main.go
new file mode 100644
index 0000000000..4fccf592b3
--- /dev/null
+++ b/scripts/telemetry-server/main.go
@@ -0,0 +1,74 @@
+// telemetry-server is a standalone HTTP server that receives telemetry
+// snapshots and prints them as a JSON stream to stdout. This is useful for
+// local development. Test with scripts/develop.sh by setting:
+//
+//	CODER_TELEMETRY_ENABLE=true CODER_TELEMETRY_URL=http://127.0.0.1:8081
+//
+// Usage:
+//
+//	go run ./scripts/telemetry-server [--port 8081]
+package main
+
+import (
+	"encoding/json"
+	"errors"
+	"flag"
+	"fmt"
+	"io"
+	"net"
+	"net/http"
+	"os"
+	"os/signal"
+	"time"
+)
+
+func main() {
+	port := flag.String("port", "8081", "Port to listen on")
+	flag.Parse()
+
+	enc := json.NewEncoder(os.Stdout)
+
+	mux := http.NewServeMux()
+
+	handleTelemetry := func(telemetryType string) http.HandlerFunc {
+		return func(w http.ResponseWriter, r *http.Request) {
+			body, err := io.ReadAll(r.Body)
+			if err != nil {
+				http.Error(w, err.Error(), http.StatusBadRequest)
+				return
+			}
+
+			output := map[string]any{
+				"type":    telemetryType,
+				"version": r.Header.Get("X-Telemetry-Version"),
+				"data":    json.RawMessage(body),
+			}
+			_ = enc.Encode(output)
+
+			w.WriteHeader(http.StatusAccepted)
+		}
+	}
+
+	mux.HandleFunc("POST /snapshot", handleTelemetry("snapshot"))
+	mux.HandleFunc("POST /deployment", handleTelemetry("deployment"))
+
+	addr := net.JoinHostPort("127.0.0.1", *port)
+	server := &http.Server{
+		Addr:              addr,
+		Handler:           mux,
+		ReadHeaderTimeout: 10 * time.Second,
+	}
+
+	go func() {
+		c := make(chan os.Signal, 1)
+		signal.Notify(c, os.Interrupt)
+		<-c
+		_ = server.Close()
+	}()
+
+	_, _ = fmt.Fprintf(os.Stdout, "Mock telemetry server listening on %s\n", addr)
+	if err := server.ListenAndServe(); err != nil && !errors.Is(err, http.ErrServerClosed) {
+		_, _ = fmt.Fprintf(os.Stderr, "Error: %v\n", err)
+		os.Exit(1)
+	}
+}