implemnted the registration-cache endpoint

hscontrol/debug.go

@@ -105,10 +105,9 @@ func (h *Headscale) debugHTTPServer() *http.Server {
 		w.Write(dmJSON)
 	}))
 	debug.Handle("registration-cache", "Pending registrations", http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
-		// TODO(kradalby): This should be replaced with a proper state method that returns registration info
+		w.Header().Set("Content-Type", "text/plain")
-		w.Header().Set("Content-Type", "application/json")
 		w.WriteHeader(http.StatusOK)
-		w.Write([]byte("{}")) // For now, return empty object
+		w.Write([]byte(h.state.GetRegistrationCacheDebug()))
 	}))
 	debug.Handle("routes", "Routes", http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
 		w.Header().Set("Content-Type", "text/plain")

hscontrol/state/state.go

@@ -9,6 +9,7 @@ import (
 	"io"
 	"net/netip"
 	"os"
+	"strings"
 	"time"
 
 	hsdb "github.com/juanfont/headscale/hscontrol/db"
@@ -736,6 +737,43 @@ func (s *State) SetRegistrationCacheEntry(id types.RegistrationID, entry types.R
 	s.registrationCache.Set(id, entry)
 }
 
+// GetRegistrationCacheDebug returns all registration cache entries as a formatted string
+func (s *State) GetRegistrationCacheDebug() string {
+	s.mu.RLock()
+	defer s.mu.RUnlock()
+
+	items := s.registrationCache.Items()
+	if len(items) == 0 {
+		return "No pending registrations"
+	}
+
+	var result strings.Builder
+	result.WriteString(fmt.Sprintf("Registration Cache (%d entries):\n", len(items)))
+	result.WriteString("=====================================\n")
+	
+	for id, item := range items {
+		regNode := item.Object
+		result.WriteString(fmt.Sprintf("  ID: %s\n", id))
+		result.WriteString(fmt.Sprintf("  Node ID: %d\n", regNode.Node.ID))
+		result.WriteString(fmt.Sprintf("  Hostname: %s\n", regNode.Node.Hostname))
+		result.WriteString(fmt.Sprintf("  Given Name: %s\n", regNode.Node.GivenName))
+		result.WriteString(fmt.Sprintf("  User ID: %d\n", regNode.Node.UserID))
+		result.WriteString(fmt.Sprintf("  Register Method: %s\n", regNode.Node.RegisterMethod))
+		result.WriteString(fmt.Sprintf("  Expires: %v\n", item.Expiration))
+		result.WriteString(fmt.Sprintf("  Channel Status: %s\n", func() string {
+			select {
+			case <-regNode.Registered:
+				return "closed"
+			default:
+				return "open"
+			}
+		}()))
+		result.WriteString("-------------------------------------\n")
+	}
+	
+	return result.String()
+}
+
 // HandleNodeFromAuthPath handles node registration through authentication flow (like OIDC).
 func (s *State) HandleNodeFromAuthPath(
 	registrationID types.RegistrationID,

hscontrol/types/common.go

@@ -188,6 +188,19 @@ type RegisterNode struct {
 	Registered chan *Node
 }
 
+// RegisterNodeDebug is a JSON-serializable version of RegisterNode
+// that excludes the channel field to prevent JSON marshaling errors
+type RegisterNodeDebug struct {
+	Node Node `json:"node"`
+}
+
+// ToDebug converts a RegisterNode to its JSON-serializable form
+func (rn *RegisterNode) ToDebug() RegisterNodeDebug {
+	return RegisterNodeDebug{
+		Node: rn.Node,
+	}
+}
+
 // DefaultBatcherWorkers returns the default number of batcher workers.
 // Default to 3/4 of CPU cores, minimum 1, no maximum.
 func DefaultBatcherWorkers() int {