matrix-public-archive/server/routes/timeout-middleware.js

100 lines
3.5 KiB
JavaScript

'use strict';
const assert = require('assert');
const urlJoin = require('url-join');
const asyncHandler = require('../lib/express-async-handler');
const { getSerializableSpans, getActiveTraceId } = require('../tracing/tracing-middleware');
const sanitizeHtml = require('../lib/sanitize-html');
const safeJson = require('../lib/safe-json');
const config = require('../lib/config');
const basePath = config.get('basePath');
assert(basePath);
const requestTimeoutMs = config.get('requestTimeoutMs');
assert(requestTimeoutMs);
// Based off of the `connect-timeout` middleware,
// https://github.com/expressjs/timeout/blob/f2f520f335f2f2ae255d4778e908e8d38e3a4e68/index.js
async function timeoutMiddleware(req, res, next) {
const timeoutId = setTimeout(() => {
const traceId = getActiveTraceId();
const serializableSpans = getSerializableSpans();
const serializedSpans = JSON.stringify(serializableSpans);
let humanReadableSpans;
if (serializableSpans.length > 0) {
humanReadableSpans = serializableSpans.map((serializableSpan) => {
const method = serializableSpan.attributes['http.method'];
const url = serializableSpan.attributes['http.url'];
const statusCode = serializableSpan.attributes['http.status_code'];
let durationString = `request is still running (${
Date.now() - serializableSpan.startTimeInMs
}ms so far)`;
if (serializableSpan.durationInMs) {
durationString = `took ${serializableSpan.durationInMs}ms`;
}
return `<li class="tracing-span-list-item">
<div class="tracing-span-item-http-details">${statusCode ?? '🏃'}: ${method} ${url}</div>
<div class="tracing-span-item-sub-details">${durationString}</div>
</li>`;
});
} else {
const noTracingDataAvailableItem = `<li class="tracing-span-list-item">
<div class="tracing-span-item-http-details">No tracing data available</div>
</li>`;
humanReadableSpans = [noTracingDataAvailableItem];
}
const hydrogenStylesUrl = urlJoin(basePath, '/hydrogen-styles.css');
const stylesUrl = urlJoin(basePath, '/css/styles.css');
const pageHtml = `
<!doctype html>
<html lang="en">
<head>
<meta name="viewport" content="width=device-width, initial-scale=1">
<title>Server timeout - Matrix Public Archive</title>
<link href="${hydrogenStylesUrl}" rel="stylesheet">
<link href="${stylesUrl}" rel="stylesheet">
</head>
${/* We add the .hydrogen class here just to get normal body styles */ ''}
<body class="hydrogen">
<h1>504: Server timeout</h1>
<p>Server was unable to respond in time (${requestTimeoutMs / 1000}s)</p>
<h3>These are the external API requests that made it slow:</h3>
${sanitizeHtml(`<ul class="tracing-span-list">
${humanReadableSpans.join('\n')}
</ul>`)}
${sanitizeHtml(
`<h2>Trace ID: <span class="heading-sub-detail">${
traceId ?? `none (tracing is probably not enabled)`
}</span></h2>`
)}
<script type="text/javascript">window.tracingSpansForRequest = ${safeJson(
serializedSpans
)};</script>
</body>
</html>
`;
// 504 Gateway timeout
res.status(504);
res.set('Content-Type', 'text/html');
res.send(pageHtml);
}, requestTimeoutMs);
res.on('finish', function () {
clearTimeout(timeoutId);
});
next();
}
module.exports = asyncHandler(timeoutMiddleware);