forward mode, cache opt, ACL, rate limit, admin/health, systemd, fix UDP reply

1 files changed, 62 insertions, 0 deletions

diff --git a/internal/server/admin.go b/internal/server/admin.go
new file mode 100644
index 0000000..46242d4
--- /dev/null
+++ b/internal/server/admin.go
@@ -0,0 +1,62 @@
+package server
+
+import (
+	"fmt"
+	"log/slog"
+	"net/http"
+)
+
+type Admin struct {
+	server *http.Server
+	s      *Server
+}
+
+func NewAdmin(listen string, s *Server) *Admin {
+	if listen == "" {
+		return nil
+	}
+
+	mux := http.NewServeMux()
+	a := &Admin{
+		server: &http.Server{
+			Addr:    listen,
+			Handler: mux,
+		},
+		s: s,
+	}
+	mux.HandleFunc("/health", a.healthHandler)
+	return a
+}
+
+func (a *Admin) Start() {
+	if a == nil {
+		return
+	}
+	go func() {
+		slog.Info("admin server listening", "addr", a.server.Addr)
+		if err := a.server.ListenAndServe(); err != nil &&
+			err != http.ErrServerClosed {
+			slog.Error("admin server failed", "error", err)
+		}
+	}()
+}
+
+func (a *Admin) Close() error {
+	if a == nil {
+		return nil
+	}
+	return a.server.Close()
+}
+
+func (a *Admin) healthHandler(w http.ResponseWriter, r *http.Request) {
+	if a.s == nil {
+		http.Error(w, "not ready", http.StatusServiceUnavailable)
+		return
+	}
+	if a.s.Ready() {
+		w.WriteHeader(http.StatusOK)
+		fmt.Fprint(w, "ok\n")
+		return
+	}
+	http.Error(w, "not ready", http.StatusServiceUnavailable)
+}