infisical/backend/src/server/plugins/serve-ui.ts

import path from "node:path";

import staticServe from "@fastify/static";

import { getConfig, IS_PACKAGED } from "@app/lib/config/env";

// to enabled this u need to set standalone mode to true
export const registerServeUI = async (
  server: FastifyZodProvider,
  {
    standaloneMode,
    dir
  }: {
    standaloneMode?: boolean;
    dir: string;
  }
) => {
  // use this only for frontend runtime static non-sensitive configuration in standalone mode
  // that app needs before loading like posthog dsn key
  // for most of the other usecase use server config
  server.route({
    method: "GET",
    url: "/runtime-ui-env.js",
    schema: {
      hide: true
    },
    handler: (_req, res) => {
      const appCfg = getConfig();
      void res.type("application/javascript");
      const config = {
        CAPTCHA_SITE_KEY: appCfg.CAPTCHA_SITE_KEY,
        POSTHOG_API_KEY: appCfg.POSTHOG_PROJECT_API_KEY,
        INTERCOM_ID: appCfg.INTERCOM_ID,
        TELEMETRY_CAPTURING_ENABLED: appCfg.TELEMETRY_ENABLED
      };
      const js = `window.__INFISICAL_RUNTIME_ENV__ = Object.freeze(${JSON.stringify(config)});`;
      return res.send(js);
    }
  });

  if (standaloneMode) {
    const frontendName = IS_PACKAGED ? "frontend" : "frontend-build";
    const frontendPath = path.join(dir, frontendName);
    await server.register(staticServe, {
      root: frontendPath,
      wildcard: false
    });

    server.route({
      method: "GET",
      url: "/*",
      schema: {
        hide: true
      },
      handler: (request, reply) => {
        if (request.url.startsWith("/api")) {
          reply.callNotFound();
          return;
        }

        // This should help avoid caching any chunks (temp fix)
        void reply.header("Cache-Control", "no-cache, no-store, must-revalidate, private, max-age=0");
        void reply.header("Pragma", "no-cache");
        void reply.header("Expires", "0");
        return reply.sendFile("index.html");
      }
    });
  }
};