Files
trade-frontend/services/frontend/server.mjs

281 lines
8.4 KiB
JavaScript

import crypto from 'node:crypto';
import fs from 'node:fs';
import http from 'node:http';
import https from 'node:https';
import path from 'node:path';
const PORT = Number.parseInt(process.env.PORT || '8081', 10);
if (!Number.isInteger(PORT) || PORT <= 0) throw new Error(`Invalid PORT: ${process.env.PORT}`);
const APP_VERSION = String(process.env.APP_VERSION || 'v1').trim() || 'v1';
const BUILD_TIMESTAMP = String(process.env.BUILD_TIMESTAMP || '').trim() || undefined;
const STARTED_AT = new Date().toISOString();
const STATIC_DIR = process.env.STATIC_DIR || '/srv';
const BASIC_AUTH_FILE = process.env.BASIC_AUTH_FILE || '/tokens/frontend.json';
const API_READ_TOKEN_FILE = process.env.API_READ_TOKEN_FILE || '/tokens/read.json';
const API_UPSTREAM = process.env.API_UPSTREAM || process.env.API_URL || 'http://api:8787';
const BASIC_AUTH_MODE = String(process.env.BASIC_AUTH_MODE || 'on')
.trim()
.toLowerCase();
const BASIC_AUTH_ENABLED = !['off', 'false', '0', 'disabled', 'none'].includes(BASIC_AUTH_MODE);
function readJson(filePath) {
const raw = fs.readFileSync(filePath, 'utf8');
return JSON.parse(raw);
}
function timingSafeEqualStr(a, b) {
const aa = Buffer.from(String(a), 'utf8');
const bb = Buffer.from(String(b), 'utf8');
if (aa.length !== bb.length) return false;
return crypto.timingSafeEqual(aa, bb);
}
function loadBasicAuth() {
const j = readJson(BASIC_AUTH_FILE);
const username = (j?.username || '').toString();
const password = (j?.password || '').toString();
if (!username || !password) throw new Error(`Invalid BASIC_AUTH_FILE: ${BASIC_AUTH_FILE}`);
return { username, password };
}
function loadApiReadToken() {
const j = readJson(API_READ_TOKEN_FILE);
const token = (j?.token || '').toString();
if (!token) throw new Error(`Invalid API_READ_TOKEN_FILE: ${API_READ_TOKEN_FILE}`);
return token;
}
function send(res, status, headers, body) {
res.statusCode = status;
for (const [k, v] of Object.entries(headers || {})) res.setHeader(k, v);
if (body == null) return void res.end();
res.end(body);
}
function basicAuthRequired(res) {
res.setHeader('www-authenticate', 'Basic realm="trade"');
send(res, 401, { 'content-type': 'text/plain; charset=utf-8' }, 'unauthorized');
}
function isAuthorized(req, creds) {
const auth = req.headers.authorization || '';
const m = String(auth).match(/^Basic\s+(.+)$/i);
if (!m?.[1]) return false;
let decoded;
try {
decoded = Buffer.from(m[1], 'base64').toString('utf8');
} catch {
return false;
}
const idx = decoded.indexOf(':');
if (idx < 0) return false;
const u = decoded.slice(0, idx);
const p = decoded.slice(idx + 1);
return timingSafeEqualStr(u, creds.username) && timingSafeEqualStr(p, creds.password);
}
const MIME = {
'.html': 'text/html; charset=utf-8',
'.css': 'text/css; charset=utf-8',
'.js': 'application/javascript; charset=utf-8',
'.mjs': 'application/javascript; charset=utf-8',
'.json': 'application/json; charset=utf-8',
'.svg': 'image/svg+xml',
'.png': 'image/png',
'.jpg': 'image/jpeg',
'.jpeg': 'image/jpeg',
'.gif': 'image/gif',
'.ico': 'image/x-icon',
'.txt': 'text/plain; charset=utf-8',
'.map': 'application/json; charset=utf-8',
};
function contentTypeFor(filePath) {
return MIME[path.extname(filePath).toLowerCase()] || 'application/octet-stream';
}
function safePathFromUrlPath(urlPath) {
const decoded = decodeURIComponent(urlPath);
const cleaned = decoded.replace(/\0/g, '');
// strip leading slash so join() doesn't ignore STATIC_DIR
const rel = cleaned.replace(/^\/+/, '');
const normalized = path.normalize(rel);
// prevent traversal
if (normalized.startsWith('..') || path.isAbsolute(normalized)) return null;
return normalized;
}
function serveStatic(req, res) {
if (req.method !== 'GET' && req.method !== 'HEAD') {
send(res, 405, { 'content-type': 'text/plain; charset=utf-8' }, 'method_not_allowed');
return;
}
const url = new URL(req.url || '/', `http://${req.headers.host || 'localhost'}`);
const rel = safePathFromUrlPath(url.pathname);
if (rel == null) {
send(res, 400, { 'content-type': 'text/plain; charset=utf-8' }, 'bad_request');
return;
}
const root = path.resolve(STATIC_DIR);
const fileCandidate = path.resolve(root, rel);
if (!fileCandidate.startsWith(root)) {
send(res, 400, { 'content-type': 'text/plain; charset=utf-8' }, 'bad_request');
return;
}
const trySend = (filePath) => {
try {
const st = fs.statSync(filePath);
if (st.isDirectory()) return trySend(path.join(filePath, 'index.html'));
res.statusCode = 200;
res.setHeader('content-type', contentTypeFor(filePath));
res.setHeader('cache-control', filePath.endsWith('index.html') ? 'no-cache' : 'public, max-age=31536000');
if (req.method === 'HEAD') return void res.end();
fs.createReadStream(filePath).pipe(res);
return true;
} catch {
return false;
}
};
// exact file, otherwise SPA fallback
if (trySend(fileCandidate)) return;
const indexPath = path.join(root, 'index.html');
if (trySend(indexPath)) return;
send(res, 404, { 'content-type': 'text/plain; charset=utf-8' }, 'not_found');
}
function stripHopByHopHeaders(headers) {
const hop = new Set([
'connection',
'keep-alive',
'proxy-authenticate',
'proxy-authorization',
'te',
'trailer',
'transfer-encoding',
'upgrade',
]);
const out = {};
for (const [k, v] of Object.entries(headers || {})) {
if (hop.has(k.toLowerCase())) continue;
out[k] = v;
}
return out;
}
function proxyApi(req, res, apiReadToken) {
const upstreamBase = new URL(API_UPSTREAM);
const inUrl = new URL(req.url || '/', `http://${req.headers.host || 'localhost'}`);
const prefix = '/api';
const strippedPath = inUrl.pathname === prefix ? '/' : inUrl.pathname.startsWith(prefix + '/') ? inUrl.pathname.slice(prefix.length) : null;
if (strippedPath == null) {
send(res, 404, { 'content-type': 'text/plain; charset=utf-8' }, 'not_found');
return;
}
const target = new URL(upstreamBase.toString());
target.pathname = strippedPath || '/';
target.search = inUrl.search;
const isHttps = target.protocol === 'https:';
const lib = isHttps ? https : http;
const headers = stripHopByHopHeaders(req.headers);
delete headers.authorization; // basic auth from client must not leak upstream
headers.host = target.host;
headers.authorization = `Bearer ${apiReadToken}`;
const upstreamReq = lib.request(
{
protocol: target.protocol,
hostname: target.hostname,
port: target.port || (isHttps ? 443 : 80),
method: req.method,
path: target.pathname + target.search,
headers,
},
(upstreamRes) => {
const outHeaders = stripHopByHopHeaders(upstreamRes.headers);
res.writeHead(upstreamRes.statusCode || 502, outHeaders);
upstreamRes.pipe(res);
}
);
upstreamReq.on('error', (err) => {
if (!res.headersSent) {
send(res, 502, { 'content-type': 'text/plain; charset=utf-8' }, `bad_gateway: ${err?.message || err}`);
} else {
res.destroy();
}
});
req.pipe(upstreamReq);
}
function handler(req, res) {
if (req.method === 'GET' && (req.url === '/healthz' || req.url?.startsWith('/healthz?'))) {
send(
res,
200,
{ 'content-type': 'application/json; charset=utf-8' },
JSON.stringify({ ok: true, version: APP_VERSION, buildTimestamp: BUILD_TIMESTAMP, startedAt: STARTED_AT })
);
return;
}
if (BASIC_AUTH_ENABLED) {
let creds;
try {
creds = loadBasicAuth();
} catch (e) {
send(res, 500, { 'content-type': 'text/plain; charset=utf-8' }, String(e?.message || e));
return;
}
if (!isAuthorized(req, creds)) {
basicAuthRequired(res);
return;
}
}
if (req.url?.startsWith('/api') && (req.url === '/api' || req.url.startsWith('/api/'))) {
let token;
try {
token = loadApiReadToken();
} catch (e) {
send(res, 500, { 'content-type': 'text/plain; charset=utf-8' }, String(e?.message || e));
return;
}
proxyApi(req, res, token);
return;
}
serveStatic(req, res);
}
const server = http.createServer(handler);
server.listen(PORT, () => {
console.log(
JSON.stringify(
{
service: 'trade-frontend',
port: PORT,
staticDir: STATIC_DIR,
apiUpstream: API_UPSTREAM,
basicAuthFile: BASIC_AUTH_FILE,
basicAuthMode: BASIC_AUTH_MODE,
apiReadTokenFile: API_READ_TOKEN_FILE,
},
null,
2
)
);
});