index.js

import app from "./app.js";
import { logger, initLogCorrelation } from "./utils/logging.js";
import { fetchProjectId } from "./utils/metadata.js";

/**
 * Initialize app and start Express server
 */
const main = async () => {
  let project = process.env.GOOGLE_CLOUD_PROJECT;
  if (!project) {
    try {
      project = await fetchProjectId();
    } catch (err) {
      logger.warn("Could not fetch Project Id for tracing.");
    }
  }
  // Initialize request-based logger with project Id
  initLogCorrelation(project);

  // Start server listening on PORT env var
  const PORT = process.env.PORT || 8080;
  app.listen(PORT, () => logger.info(`Listening on port ${PORT}`));
};

/**
 * Listen for termination signal
 */
process.on("SIGTERM", () => {
  // Clean up resources on shutdown
  logger.info("Caught SIGTERM.");
  logger.flush();
});

main();