backend/scripts/websites-agent/server.js

const http = require('http');
const { spawn } = require('child_process');
const { timingSafeEqual } = require('crypto');
const fs = require('fs');
const path = require('path');

const PORT = Number(process.env.PORT || 9050);
const ENV_FILE = path.join(__dirname, '.env');

function loadEnvFile() {
  try {
    const raw = fs.readFileSync(ENV_FILE, 'utf8');
    for (const line of raw.split('\n')) {
      const trimmed = line.trim();
      if (!trimmed || trimmed.startsWith('#')) continue;
      const i = trimmed.indexOf('=');
      if (i <= 0) continue;
      const key = trimmed.slice(0, i).trim();
      const val = trimmed.slice(i + 1).trim();
      process.env[key] = val;
    }
  } catch (_) {
    /* optional */
  }
}

loadEnvFile();

function token() {
  return String(process.env.DEPLOY_TOKEN || '').trim();
}

function allowedSlugs() {
  loadEnvFile();
  return new Set(
    String(process.env.ALLOWED_SLUGS || '')
      .split(',')
      .map((s) => s.trim())
      .filter(Boolean),
  );
}

function safeEqual(a, b) {
  const x = Buffer.from(a);
  const y = Buffer.from(b);
  if (x.length !== y.length) return false;
  return timingSafeEqual(x, y);
}

function readJson(req) {
  return new Promise((resolve, reject) => {
    const chunks = [];
    req.on('data', (c) => chunks.push(c));
    req.on('end', () => {
      try {
        const raw = Buffer.concat(chunks).toString('utf8') || '{}';
        resolve(JSON.parse(raw));
      } catch (e) {
        reject(e);
      }
    });
    req.on('error', reject);
  });
}

function send(res, status, body) {
  const data = JSON.stringify(body);
  res.writeHead(status, {
    'Content-Type': 'application/json',
    'Content-Length': Buffer.byteLength(data),
  });
  res.end(data);
}

function assertAuth(req, res) {
  const provided = String(req.headers['x-deploy-token'] || '').trim();
  const expected = token();
  if (!expected || !provided || !safeEqual(provided, expected)) {
    send(res, 401, { error: 'unauthorized' });
    return false;
  }
  return true;
}

function runScript(script, args) {
  return new Promise((resolve, reject) => {
    const child = spawn(script, args, {
      stdio: ['ignore', 'pipe', 'pipe'],
    });
    let stdout = '';
    let stderr = '';
    child.stdout.on('data', (d) => {
      stdout += d.toString();
    });
    child.stderr.on('data', (d) => {
      stderr += d.toString();
    });
    child.on('error', reject);
    child.on('close', (code) => {
      if (code === 0) resolve({ stdout, stderr });
      else reject(new Error(stderr || stdout || `exit ${code}`));
    });
  });
}

const server = http.createServer(async (req, res) => {
  if (req.method === 'GET' && req.url === '/health') {
    return send(res, 200, { ok: true, allowed: [...allowedSlugs()] });
  }

  if (req.method === 'POST' && req.url === '/deploy') {
    if (!assertAuth(req, res)) return;

    let body;
    try {
      body = await readJson(req);
    } catch {
      return send(res, 400, { error: 'invalid json' });
    }

    const slug = String(body.slug || '').trim();
    if (!slug || !allowedSlugs().has(slug)) {
      return send(res, 400, { error: 'unknown or disallowed slug' });
    }

    const child = spawn('/opt/websites-agent/deploy.sh', [slug], {
      detached: true,
      stdio: 'ignore',
    });
    child.unref();

    return send(res, 202, { status: 'accepted', slug });
  }

  if (req.method === 'POST' && req.url === '/provision') {
    if (!assertAuth(req, res)) return;

    let body;
    try {
      body = await readJson(req);
    } catch {
      return send(res, 400, { error: 'invalid json' });
    }

    const slug = String(body.slug || '').trim();
    const host = String(body.host || '').trim().toLowerCase();
    const gitRepoUrl = String(body.gitRepoUrl || body.git_repo_url || '').trim();

    if (!slug || !host || !gitRepoUrl) {
      return send(res, 400, { error: 'slug, host, and gitRepoUrl are required' });
    }

    if (!/^[a-z0-9]+(-[a-z0-9]+)*$/.test(slug)) {
      return send(res, 400, { error: 'invalid slug' });
    }

    try {
      const result = await runScript('/opt/websites-agent/provision.sh', [
        slug,
        host,
        gitRepoUrl,
      ]);
      // Reload allowlist from .env (provision.sh appends slug)
      loadEnvFile();
      return send(res, 200, {
        status: 'provisioned',
        slug,
        host,
        log: (result.stdout || '').slice(-2000),
      });
    } catch (err) {
      return send(res, 500, {
        error: 'provision failed',
        detail: err instanceof Error ? err.message.slice(0, 2000) : String(err),
      });
    }
  }

  return send(res, 404, { error: 'not found' });
});

server.listen(PORT, '0.0.0.0', () => {
  console.log('websites-deploy-agent listening on :' + PORT);
});