oidc: Add /api/v1/config route for determining whether to display a login button on the UI

controller/handler/config.go

@@ -0,0 +1,26 @@
+package handler
+
+import (
+	"fmt"
+	"net/http"
+
+	"github.com/TwiN/gatus/v3/security"
+)
+
+// ConfigHandler is a handler that returns information for the front end of the application.
+type ConfigHandler struct {
+	securityConfig *security.Config
+}
+
+func (handler ConfigHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
+	hasOIDC := false
+	isAuthenticated := false // Default to true if no security config is set
+	if handler.securityConfig != nil {
+		hasOIDC = handler.securityConfig.OIDC != nil
+		isAuthenticated = handler.securityConfig.IsAuthenticated(r)
+	}
+	// Return the config
+	w.Header().Set("Content-Type", "application/json")
+	w.WriteHeader(http.StatusOK)
+	_, _ = w.Write([]byte(fmt.Sprintf(`{"oidc":%v,"authenticated":%v}`, hasOIDC, isAuthenticated)))
+}