anvil/striker-ui-api/src/index.ts

import { getgid, getuid, setgid, setuid } from 'process';

import { PGID, PUID, PORT, ECODE_DROP_PRIVILEGES } from './lib/consts';

import app from './app';
import { stderr, stdout } from './lib/shell';

stdout(`Starting process with ownership ${getuid()}:${getgid()}`);

app.listen(PORT, () => {
  try {
    // Group must be set before user to avoid permission error.
    setgid(PGID);
    setuid(PUID);

    stdout(`Process ownership changed to ${getuid()}:${getgid()}.`);
  } catch (error) {
    stderr(`Failed to change process ownership; CAUSE: ${error}`);

    process.exit(ECODE_DROP_PRIVILEGES);
  }

  stdout(`Listening on localhost:${PORT}.`);
});