feat: Add POST /api/reload endpoint for config reload

- Add /api/reload endpoint that triggers configuration reload
- Always requires API key authentication (even if api.access is public)
- Returns error if no API keys are configured
- Update config.example.yaml with new endpoint and {group}/{name} format docs

1 files changed, 79 insertions, 26 deletions

diff --git a/internal/server/server.go b/internal/server/server.go
index b47bf79..ab9ff24 100644
--- a/internal/server/server.go
+++ b/internal/server/server.go
@@ -28,14 +28,18 @@ var templatesFS embed.FS
 //go:embed static/*
 var staticFS embed.FS
 
+// ReloadFunc is a callback function for reloading configuration
+type ReloadFunc func() error
+
 // Server handles HTTP requests for the status page
 type Server struct {
-	config    *config.Config
-	storage   *storage.Storage
-	scheduler *monitor.Scheduler
-	logger    *slog.Logger
-	server    *http.Server
-	templates *template.Template
+	config       *config.Config
+	storage      *storage.Storage
+	scheduler    *monitor.Scheduler
+	logger       *slog.Logger
+	server       *http.Server
+	templates    *template.Template
+	reloadConfig ReloadFunc
 }
 
 // New creates a new HTTP server
@@ -89,6 +93,9 @@ func New(cfg *config.Config, store *storage.Storage, sched *monitor.Scheduler, l
 		mux.HandleFunc("GET /api/page", s.withAPIAuth(s.handleAPIPage))
 	}
 
+	// Config reload endpoint - always requires authentication
+	mux.HandleFunc("POST /api/reload", s.withStrictAuth(s.handleAPIReload))
+
 	// Create HTTP server
 	s.server = &http.Server{
 		Addr:         fmt.Sprintf("%s:%d", cfg.Server.Host, cfg.Server.Port),
@@ -145,39 +152,59 @@ func (s *Server) withAPIAuth(handler http.HandlerFunc) http.HandlerFunc {
 			return
 
 		case "authenticated":
-			// Check for API key in header or query param
-			apiKey := r.Header.Get("X-API-Key")
-			if apiKey == "" {
-				apiKey = r.URL.Query().Get("api_key")
-			}
-
-			if apiKey == "" {
+			if !s.checkAPIKey(r) {
 				w.Header().Set("WWW-Authenticate", "API-Key")
 				s.jsonError(w, "API key required", http.StatusUnauthorized)
 				return
 			}
 
-			// Check if key is valid
-			valid := false
-			for _, key := range s.config.API.Keys {
-				if key == apiKey {
-					valid = true
-					break
-				}
-			}
+			// case "public" or default: allow access
+		}
 
-			if !valid {
-				s.jsonError(w, "Invalid API key", http.StatusUnauthorized)
-				return
-			}
+		handler(w, r)
+	}
+}
 
-			// case "public" or default: allow access
+// withStrictAuth wraps an API handler that always requires authentication,
+// regardless of the api.access setting. Used for sensitive operations like config reload.
+func (s *Server) withStrictAuth(handler http.HandlerFunc) http.HandlerFunc {
+	return func(w http.ResponseWriter, r *http.Request) {
+		// Always require API key, even if api.access is "public"
+		if len(s.config.API.Keys) == 0 {
+			s.jsonError(w, "No API keys configured. Add keys to api.keys in config to use this endpoint.", http.StatusForbidden)
+			return
+		}
+
+		if !s.checkAPIKey(r) {
+			w.Header().Set("WWW-Authenticate", "API-Key")
+			s.jsonError(w, "API key required", http.StatusUnauthorized)
+			return
 		}
 
 		handler(w, r)
 	}
 }
 
+// checkAPIKey validates the API key from request header or query parameter
+func (s *Server) checkAPIKey(r *http.Request) bool {
+	apiKey := r.Header.Get("X-API-Key")
+	if apiKey == "" {
+		apiKey = r.URL.Query().Get("api_key")
+	}
+
+	if apiKey == "" {
+		return false
+	}
+
+	for _, key := range s.config.API.Keys {
+		if key == apiKey {
+			return true
+		}
+	}
+
+	return false
+}
+
 // PageData contains data for rendering the status page
 type PageData struct {
 	Site               config.SiteConfig
@@ -991,6 +1018,32 @@ func (s *Server) handleAPIIncidents(w http.ResponseWriter, r *http.Request) {
 	})
 }
 
+// SetReloadFunc sets the callback function for reloading configuration
+func (s *Server) SetReloadFunc(fn ReloadFunc) {
+	s.reloadConfig = fn
+}
+
+// handleAPIReload triggers a configuration reload (always requires authentication)
+func (s *Server) handleAPIReload(w http.ResponseWriter, r *http.Request) {
+	if s.reloadConfig == nil {
+		s.jsonError(w, "Reload function not configured", http.StatusServiceUnavailable)
+		return
+	}
+
+	s.logger.Info("config reload triggered via API", "remote_addr", r.RemoteAddr)
+
+	if err := s.reloadConfig(); err != nil {
+		s.logger.Error("config reload failed", "error", err)
+		s.jsonError(w, fmt.Sprintf("Reload failed: %v", err), http.StatusInternalServerError)
+		return
+	}
+
+	s.jsonResponse(w, map[string]string{
+		"status":  "ok",
+		"message": "Configuration reloaded successfully",
+	})
+}
+
 // jsonResponse writes a JSON response
 func (s *Server) jsonResponse(w http.ResponseWriter, data interface{}) {
 	w.Header().Set("Content-Type", "application/json")