add rate limiting, CSRF, newsletter, auto-checker, /uses and /projects pages

internal/checker/checker.go

@@ -0,0 +1,88 @@
+// Package checker periodically HTTP-checks services and updates status.json.
+package checker
+
+import (
+	"log"
+	"net/http"
+	"path/filepath"
+	"time"
+
+	"ridgwaysystems.org/website/internal/status"
+)
+
+// Start launches the background checker. It checks services every interval
+// and updates status.json in dataDir. Services without a CheckURL are skipped.
+func Start(dataDir string, interval time.Duration) {
+	go run(dataDir, interval)
+}
+
+func run(dataDir string, interval time.Duration) {
+	client := &http.Client{
+		Timeout: 10 * time.Second,
+		CheckRedirect: func(req *http.Request, via []*http.Request) error {
+			if len(via) >= 3 {
+				return http.ErrUseLastResponse
+			}
+			return nil
+		},
+	}
+	path := filepath.Join(dataDir, "status.json")
+
+	for {
+		check(client, path)
+		time.Sleep(interval)
+	}
+}
+
+func check(client *http.Client, path string) {
+	page, err := status.Load(path)
+	if err != nil {
+		log.Printf("checker: load %s: %v", path, err)
+		return
+	}
+
+	changed := false
+	for i, svc := range page.Services {
+		if svc.CheckURL == "" {
+			continue
+		}
+
+		prev := svc.Status
+		newStatus := probe(client, svc.CheckURL)
+		if newStatus != prev {
+			log.Printf("checker: %s %s → %s", svc.Name, prev, newStatus)
+			page.Services[i].Status = newStatus
+			changed = true
+		}
+	}
+
+	if changed {
+		if err := status.Save(path, page); err != nil {
+			log.Printf("checker: save %s: %v", path, err)
+		}
+	} else {
+		// Still update last_checked timestamp so the status page shows freshness
+		page.LastChecked = time.Now().UTC()
+		if err := status.Save(path, page); err != nil {
+			log.Printf("checker: save %s: %v", path, err)
+		}
+	}
+}
+
+func probe(client *http.Client, url string) string {
+	resp, err := client.Get(url)
+	if err != nil {
+		return "down"
+	}
+	defer resp.Body.Close()
+
+	switch {
+	case resp.StatusCode < 400:
+		return "up"
+	case resp.StatusCode >= 500:
+		return "down"
+	default:
+		// 4xx could mean the service is up but the URL is wrong; treat as degraded
+		return "degraded"
+	}
+}