Implement pathPrefix handling

Signed-off-by: Julius Volz <julius.volz@gmail.com>

web/ui/mantine-ui/src/App.tsx

@@ -60,9 +60,26 @@ import ErrorBoundary from "./ErrorBoundary";
 import { ThemeSelector } from "./ThemeSelector";
 import { SettingsContext } from "./settings";
 import { Notifications } from "@mantine/notifications";
+import { useAppDispatch } from "./state/hooks";
+import { updateSettings } from "./state/settingsSlice";
 
 const queryClient = new QueryClient();
 
+const mainNavPages = [
+  {
+    title: "Query",
+    path: "/query",
+    icon: <IconDatabaseSearch style={{ width: rem(14), height: rem(14) }} />,
+    element: <QueryPage />,
+  },
+  {
+    title: "Alerts",
+    path: "/alerts",
+    icon: <IconBellFilled style={{ width: rem(14), height: rem(14) }} />,
+    element: <AlertsPage />,
+  },
+];
+
 const monitoringStatusPages = [
   {
     title: "Targets",
@@ -114,6 +131,7 @@ const serverStatusPages = [
 ];
 
 const allStatusPages = [...monitoringStatusPages, ...serverStatusPages];
+const allPages = [...mainNavPages, ...allStatusPages];
 
 const theme = createTheme({
   colors: {
@@ -132,6 +150,21 @@ const theme = createTheme({
   },
 });
 
+// This dynamically/generically determines the pathPrefix by stripping the first known
+// endpoint suffix from the window location path. It works out of the box for both direct
+// hosting and reverse proxy deployments with no additional configurations required.
+const getPathPrefix = (path: string) => {
+  if (path.endsWith("/")) {
+    path = path.slice(0, -1);
+  }
+
+  const pagePath = allPages.find((p) => path.endsWith(p.path))?.path;
+  if (pagePath === undefined) {
+    throw new Error(`Could not find base path for ${path}`);
+  }
+  return path.slice(0, path.length - pagePath.length);
+};
+
 const navLinkIconSize = 15;
 const navLinkXPadding = "md";
 
@@ -139,26 +172,24 @@ function App() {
   const [opened, { toggle }] = useDisclosure();
   const { agentMode } = useContext(SettingsContext);
 
+  const pathPrefix = getPathPrefix(window.location.pathname);
+  const dispatch = useAppDispatch();
+  dispatch(updateSettings({ pathPrefix }));
+
   const navLinks = (
     <>
-      <Button
-        component={NavLink}
-        to="/query"
-        className={classes.link}
-        leftSection={<IconDatabaseSearch size={navLinkIconSize} />}
-        px={navLinkXPadding}
-      >
-        Query
-      </Button>
-      <Button
-        component={NavLink}
-        to="/alerts"
-        className={classes.link}
-        leftSection={<IconBellFilled size={navLinkIconSize} />}
-        px={navLinkXPadding}
-      >
-        Alerts
-      </Button>
+      {mainNavPages.map((p) => (
+        <Button
+          key={p.path}
+          component={NavLink}
+          to={p.path}
+          className={classes.link}
+          leftSection={p.icon}
+          px={navLinkXPadding}
+        >
+          {p.title}
+        </Button>
+      ))}
 
       <Menu shadow="md" width={230}>
         <Routes>
@@ -246,7 +277,7 @@ function App() {
   );
 
   return (
-    <BrowserRouter>
+    <BrowserRouter basename={pathPrefix}>
       <MantineProvider defaultColorScheme="auto" theme={theme}>
         <Notifications position="top-right" />
 

web/ui/mantine-ui/src/api/api.ts

@@ -1,4 +1,5 @@
 import { useQuery, useSuspenseQuery } from "@tanstack/react-query";
+import { useAppSelector } from "../state/hooks";
 
 export const API_PATH = "api/v1";
 
@@ -17,18 +18,29 @@ export type ErrorAPIResponse = {
 export type APIResponse<T> = SuccessAPIResponse<T> | ErrorAPIResponse;
 
 const createQueryFn =
-  <T>({ path, params }: { path: string; params?: Record<string, string> }) =>
+  <T>({
+    pathPrefix,
+    path,
+    params,
+  }: {
+    pathPrefix: string;
+    path: string;
+    params?: Record<string, string>;
+  }) =>
   async ({ signal }: { signal: AbortSignal }) => {
     const queryString = params
       ? `?${new URLSearchParams(params).toString()}`
       : "";
 
     try {
-      const res = await fetch(`/${API_PATH}/${path}${queryString}`, {
-        cache: "no-store",
-        credentials: "same-origin",
-        signal,
-      });
+      const res = await fetch(
+        `${pathPrefix}/${API_PATH}${path}${queryString}`,
+        {
+          cache: "no-store",
+          credentials: "same-origin",
+          signal,
+        }
+      );
 
       if (
         !res.ok &&
@@ -74,21 +86,32 @@ type QueryOptions = {
   enabled?: boolean;
 };
 
-export const useAPIQuery = <T>({ key, path, params, enabled }: QueryOptions) =>
-  useQuery<SuccessAPIResponse<T>>({
+export const useAPIQuery = <T>({
+  key,
+  path,
+  params,
+  enabled,
+}: QueryOptions) => {
+  const pathPrefix = useAppSelector((state) => state.settings.pathPrefix);
+
+  return useQuery<SuccessAPIResponse<T>>({
     queryKey: key ? [key] : [path, params],
     retry: false,
     refetchOnWindowFocus: false,
     gcTime: 0,
     enabled,
-    queryFn: createQueryFn({ path, params }),
+    queryFn: createQueryFn({ pathPrefix, path, params }),
   });
+};
 
-export const useSuspenseAPIQuery = <T>({ key, path, params }: QueryOptions) =>
-  useSuspenseQuery<SuccessAPIResponse<T>>({
+export const useSuspenseAPIQuery = <T>({ key, path, params }: QueryOptions) => {
+  const pathPrefix = useAppSelector((state) => state.settings.pathPrefix);
+
+  return useSuspenseQuery<SuccessAPIResponse<T>>({
     queryKey: key ? [key] : [path, params],
     retry: false,
     refetchOnWindowFocus: false,
     gcTime: 0,
-    queryFn: createQueryFn({ path, params }),
+    queryFn: createQueryFn({ pathPrefix, path, params }),
   });
+};

web/ui/mantine-ui/src/state/settingsSlice.ts

@@ -0,0 +1,23 @@
+import { PayloadAction, createSlice } from "@reduxjs/toolkit";
+
+interface Settings {
+  pathPrefix: string;
+}
+
+const initialState: Settings = {
+  pathPrefix: "",
+};
+
+export const settingsSlice = createSlice({
+  name: "settings",
+  initialState,
+  reducers: {
+    updateSettings: (state, { payload }: PayloadAction<Partial<Settings>>) => {
+      Object.assign(state, payload);
+    },
+  },
+});
+
+export const { updateSettings } = settingsSlice.actions;
+
+export default settingsSlice.reducer;

web/ui/mantine-ui/src/state/store.ts

@@ -1,9 +1,11 @@
 import { configureStore } from "@reduxjs/toolkit";
 import queryPageSlice from "./queryPageSlice";
 import { prometheusApi } from "./api";
+import settingsSlice from "./settingsSlice";
 
 const store = configureStore({
   reducer: {
+    settings: settingsSlice,
     queryPage: queryPageSlice,
     [prometheusApi.reducerPath]: prometheusApi.reducer,
   },