[minor] ping lightsout (#3)

* ping lightsout

* Add ping test

Author: joecorall

LICENSE

@@ -0,0 +1,69 @@
+DUAL LICENSE
+
+This software is available under two licenses:
+
+================================================================================
+NON-PROFIT & EDUCATIONAL LICENSE (MIT-BASED)
+================================================================================
+
+For non-profit organizations, educational institutions, and personal use:
+
+Copyright (c) 2025 LibOps, LLC.
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.
+
+This license applies ONLY to:
+✅ 501(c)(3) and other registered non-profit organizations
+✅ Educational institutions (schools, universities, libraries)
+✅ Personal/hobby use (non-commercial)
+✅ Open-source projects (also licensed under compatible terms)
+
+================================================================================
+COMMERCIAL LICENSE REQUIRED
+================================================================================
+
+For-profit companies, businesses, and commercial use require a separate
+commercial license.
+
+❌ This includes:
+
+- For-profit corporations and LLCs
+- Consulting companies and contractors
+- SaaS providers and cloud services
+- Any commercial or revenue-generating use
+
+💰 Commercial License Benefits:
+
+- Right to use without restrictions
+- Legal warranties and indemnification
+- Technical support and updates
+- Custom features and professional services
+
+📞 Contact for Commercial License:
+Email: [info@libops.io]
+Website: [www.libops.io]
+
+================================================================================
+COPYRIGHT NOTICE
+================================================================================
+
+Copyright (C) 2025 LibOps, LLC.
+All rights reserved.
+
+Unauthorized use by for-profit entities is prohibited without a commercial license.

README.md

@@ -7,12 +7,23 @@ This service is designed to run on **Google Cloud Run as an ingress layer** in f
 ## Architecture
 
 ```
-Internet → Cloud Run (PPB) → Google Compute Engine (Full App Stack)
+Internet → Cloud Run (PPB) → Google Compute Engine (Full App Stack + lightsout)
 ```
 
 - **Cloud Run**: Runs PPB as serverless ingress, scales to zero when no traffic
 - **GCE VM**: Runs your complete application (web server, database, etc.), can power off when idle
 - **PPB**: Powers on the VM when requests arrive, proxies traffic through with IP authorization
+- **lightsout**: Monitors activity and automatically shuts down VMs during idle periods (optional companion service)
+
+### Complete On-Demand Infrastructure
+
+PPB works seamlessly with [lightsout](https://github.com/libops/lightsout) to create a complete on-demand infrastructure solution:
+
+- **PPB handles startup**: Automatically powers on GCE instances when traffic arrives
+- **lightsout handles shutdown**: Monitors activity and automatically suspends instances during idle periods
+- **Cost optimization**: Only pay for compute resources when actively serving traffic
+
+Deploy lightsout alongside your application on the GCE instance to complete the automation cycle.
 
 ## Cloud Run Behavior
 

main.go

@@ -6,7 +6,11 @@ import (
 	"log/slog"
 	"net/http"
 	"os"
+	"os/signal"
 	"strings"
+	"sync"
+	"syscall"
+	"time"
 
 	"github.com/libops/ppb/pkg/config"
 	"github.com/libops/ppb/pkg/proxy"
@@ -31,6 +35,45 @@ func init() {
 	slog.SetDefault(handler)
 }
 
+func startPingRoutine(ctx context.Context, wg *sync.WaitGroup, c *config.Config, interval time.Duration) {
+	defer wg.Done()
+
+	ticker := time.NewTicker(interval)
+	defer ticker.Stop()
+
+	slog.Info("Starting ping routine to GCE instance", "interval", interval)
+
+	for {
+		select {
+		case <-ctx.Done():
+			slog.Info("Ping routine shutting down")
+			return
+		case <-ticker.C:
+			host := c.Machine.Host()
+			if host == "" {
+				slog.Debug("No GCE host IP available for ping")
+				continue
+			}
+
+			pingURL := fmt.Sprintf("http://%s:8808/ping", host)
+			slog.Debug("Pinging GCE instance", "url", pingURL)
+
+			client := &http.Client{
+				Timeout: 5 * time.Second,
+			}
+
+			resp, err := client.Get(pingURL)
+			if err != nil {
+				slog.Debug("Ping failed", "url", pingURL, "error", err)
+				continue
+			}
+			resp.Body.Close()
+
+			slog.Debug("Ping successful", "url", pingURL, "status", resp.StatusCode)
+		}
+	}
+}
+
 func main() {
 	c, err := config.LoadConfig()
 	if err != nil {
@@ -45,6 +88,14 @@ func main() {
 		c.PowerOnCooldown = 30
 	}
 
+	ctx, cancel := context.WithCancel(context.Background())
+	defer cancel()
+	sigChan := make(chan os.Signal, 1)
+	signal.Notify(sigChan, syscall.SIGTERM, syscall.SIGINT)
+	var wg sync.WaitGroup
+	wg.Add(1)
+	go startPingRoutine(ctx, &wg, c, 30*time.Second)
+
 	http.HandleFunc("/healthcheck", func(w http.ResponseWriter, r *http.Request) {
 		w.WriteHeader(http.StatusOK)
 		_, _ = fmt.Fprintln(w, "OK")
@@ -58,8 +109,8 @@ func main() {
 		}
 
 		// Attempt to power on machine with cooldown protection
-		ctx := context.Background()
-		err := c.Machine.PowerOnWithCooldown(ctx, c.PowerOnCooldown)
+		reqCtx := context.Background()
+		err := c.Machine.PowerOnWithCooldown(reqCtx, c.PowerOnCooldown)
 		if err != nil {
 			slog.Error("Power-on attempt failed", "err", err)
 			http.Error(w, "Backend not available", http.StatusServiceUnavailable)
@@ -71,8 +122,24 @@ func main() {
 		p.ServeHTTP(w, r)
 	})
 
-	slog.Info("Server listening on :8080")
-	if err := http.ListenAndServe(":8080", nil); err != nil {
-		panic(err)
+	server := &http.Server{Addr: ":8080"}
+	go func() {
+		slog.Info("Server listening on :8080")
+		if err := server.ListenAndServe(); err != nil && err != http.ErrServerClosed {
+			slog.Error("Server error", "err", err)
+		}
+	}()
+
+	<-sigChan
+	slog.Info("Received shutdown signal, gracefully shutting down...")
+	cancel()
+
+	shutdownCtx, shutdownCancel := context.WithTimeout(context.Background(), 10*time.Second)
+	defer shutdownCancel()
+	if err := server.Shutdown(shutdownCtx); err != nil {
+		slog.Error("Server shutdown error", "err", err)
 	}
+
+	wg.Wait()
+	slog.Info("Shutdown complete")
 }

main_test.go

@@ -0,0 +1,128 @@
+package main
+
+import (
+	"context"
+	"log/slog"
+	"net/http"
+	"os"
+	"strings"
+	"sync"
+	"testing"
+	"time"
+
+	"github.com/libops/ppb/pkg/config"
+	"github.com/libops/ppb/pkg/machine"
+)
+
+func TestStartPingRoutine_Integration(t *testing.T) {
+	// Track ping requests
+	var pingCount int
+	var pingURLs []string
+	var mu sync.Mutex
+
+	mux := http.NewServeMux()
+	mux.HandleFunc("/ping", func(w http.ResponseWriter, r *http.Request) {
+		mu.Lock()
+		defer mu.Unlock()
+		pingCount++
+		pingURLs = append(pingURLs, r.URL.Path)
+
+		w.WriteHeader(http.StatusOK)
+		_, err := w.Write([]byte("pong"))
+		if err != nil {
+			slog.Error("Unable to write ping response", "err", err)
+			os.Exit(1)
+		}
+	})
+	server := &http.Server{
+		Addr:    ":8808",
+		Handler: mux,
+	}
+	go func() {
+		if err := server.ListenAndServe(); err != nil && err != http.ErrServerClosed {
+			// Ignore "address already in use" errors during testing
+			if !strings.Contains(err.Error(), "address already in use") {
+				t.Errorf("Mock server error: %v", err)
+			}
+		}
+	}()
+
+	time.Sleep(1 * time.Second)
+
+	defer func() {
+		ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
+		defer cancel()
+		err := server.Shutdown(ctx)
+		if err != nil {
+			slog.Error("Server shutdown failed", "err", err)
+			os.Exit(1)
+		}
+	}()
+
+	mockMachine := machine.NewGceMachine()
+	mockMachine.SetHostForTesting("127.0.0.1")
+
+	config := &config.Config{
+		Machine: mockMachine,
+	}
+
+	ctx, cancel := context.WithTimeout(context.Background(), 350*time.Millisecond)
+	defer cancel()
+
+	var wg sync.WaitGroup
+	wg.Add(1)
+
+	go startPingRoutine(ctx, &wg, config, 100*time.Millisecond)
+	wg.Wait()
+
+	mu.Lock()
+	defer mu.Unlock()
+
+	if pingCount == 0 {
+		t.Error("Expected at least one ping request, got none")
+	}
+
+	// Verify all requests were to /ping endpoint
+	for _, url := range pingURLs {
+		if url != "/ping" {
+			t.Errorf("Expected ping to /ping endpoint, got %s", url)
+		}
+	}
+
+	// Should have made multiple pings (at least 2-3 in 350ms with 100ms interval)
+	if pingCount < 2 {
+		t.Errorf("Expected at least 2 ping requests, got %d", pingCount)
+	}
+}
+
+func TestStartPingRoutine_ContextCancellation(t *testing.T) {
+	mockMachine := machine.NewGceMachine()
+	mockMachine.SetHostForTesting("127.0.0.1")
+
+	config := &config.Config{
+		Machine: mockMachine,
+	}
+
+	ctx, cancel := context.WithCancel(context.Background())
+	var wg sync.WaitGroup
+	wg.Add(1)
+
+	routineFinished := make(chan bool, 1)
+
+	go func() {
+		startPingRoutine(ctx, &wg, config, 50*time.Millisecond)
+		routineFinished <- true
+	}()
+
+	time.Sleep(100 * time.Millisecond)
+	cancel()
+
+	wg.Wait()
+
+	// Verify the routine actually finished
+	select {
+	case <-routineFinished:
+	case <-time.After(1 * time.Second):
+		t.Error("Ping routine did not finish within expected time after context cancellation")
+	}
+}