const onFinished = require('on-finished'); const promClient = require('prom-client'); const normalizePath = require('./normalizePath'); const normalizeStatusCode = require('./normalizeStatusCode'); function matchVsRegExps(element, regexps) { for (const regexp of regexps) { if (regexp instanceof RegExp) { if (element.match(regexp)) { return true; } } else if (element === regexp) { return true; } } return false; } function clusterMetrics() { const aggregatorRegistry = new promClient.AggregatorRegistry(); const metricsMiddleware = function(req, res) { function sendClusterMetrics(clusterMetrics) { res.set('Content-Type', aggregatorRegistry.contentType); res.send(clusterMetrics); } function sendClusterMetricsError(err) { console.error(err); return res.sendStatus(500); } // since prom-client@13 clusterMetrics() method doesn't take cb param, // but we provide it anyway, as at this stage it's unknown which version of prom-client is used const response = aggregatorRegistry.clusterMetrics((err, clusterMetrics) => { if (err) { return sendClusterMetricsError(err); } sendClusterMetrics(clusterMetrics); }); // if we find out that it was a promise and our cb was useless... if (response && response.then) { response .then(result => sendClusterMetrics(result)) .catch(err => sendClusterMetricsError(err)); } }; return metricsMiddleware; } function main(opts) { if (arguments[2] && arguments[1] && arguments[1].send) { arguments[1].status(500) .send('

# 500 Error

\n' + '

Unexpected 3rd param in express-prom-bundle.\n' + '

Did you just put express-prom-bundle into app.use ' + 'without calling it as a function first?'); return; } opts = Object.assign( { autoregister: true, includeStatusCode: true, normalizePath: main.normalizePath, formatStatusCode: main.normalizeStatusCode, metricType: 'histogram', promClient: {}, promRegistry: promClient.register, metricsApp: null, }, opts ); if (opts.prefix || opts.keepDefaultMetrics !== undefined || opts.whitelist !== undefined || opts.blacklist !== undefined ) { throw new Error( 'express-prom-bundle detected one of the obsolete options: ' + 'prefix, keepDefaultMetrics, whitelist, blacklist. ' + 'Please refer to oficial docs. ' + 'Most likely you upgraded the module without the necessary code changes' ); } if (opts.promClient.collectDefaultMetrics) { promClient.collectDefaultMetrics(opts.promClient.collectDefaultMetrics); } const httpMetricName = opts.httpDurationMetricName || 'http_request_duration_seconds'; function makeHttpMetric() { const labels = ['status_code']; if (opts.includeMethod) { labels.push('method'); } if (opts.includePath) { labels.push('path'); } if (opts.customLabels) { labels.push.apply(labels, Object.keys(opts.customLabels)); } if (opts.metricType === 'summary') { return new promClient.Summary({ name: httpMetricName, help: 'duration summary of http responses labeled with: ' + labels.join(', '), labelNames: labels, percentiles: opts.percentiles || [0.5, 0.75, 0.95, 0.98, 0.99, 0.999], maxAgeSeconds: opts.maxAgeSeconds, ageBuckets: opts.ageBuckets, registers: [opts.promRegistry], pruneAgedBuckets: opts.pruneAgedBuckets }); } else if (opts.metricType === 'histogram' || !opts.metricType) { return new promClient.Histogram({ name: httpMetricName, help: 'duration histogram of http responses labeled with: ' + labels.join(', '), labelNames: labels, buckets: opts.buckets || [0.003, 0.03, 0.1, 0.3, 1.5, 10], registers: [opts.promRegistry] }); } else { throw new Error('metricType option must be histogram or summary'); } } const metrics = { [httpMetricName]: makeHttpMetric() }; if (opts.includeUp !== false) { let prefix = ''; if (opts.promClient && opts.promClient.collectDefaultMetrics) { prefix = opts.promClient.collectDefaultMetrics.prefix || ''; } metrics.up = new promClient.Gauge({ name: `${prefix}up`, help: '1 = up, 0 = not up', registers: [opts.promRegistry] }); metrics.up.set(1); } const metricsMiddleware = function(req, res, next) { const sendSuccesss = (output) => { res.writeHead(200, {'Content-Type': 'text/plain'}); res.end(output); }; const metricsResponse = opts.promRegistry.metrics(); // starting from prom-client@13 .metrics() returns a Promise if (metricsResponse.then) { metricsResponse .then(output => sendSuccesss(output)) .catch(err => next(err)); } else { // compatibility fallback for previous versions of prom-client@<=12 sendSuccesss(metricsResponse); } }; const metricsMatch = opts.metricsPath instanceof RegExp ? opts.metricsPath : new RegExp('^' + (opts.metricsPath || '/metrics') + '/?$'); if (typeof opts.bypass === 'function') { opts.bypass = { onRequest: opts.bypass }; } else if (!opts.bypass) { opts.bypass = {}; } const middleware = function (req, res, next) { const path = req.originalUrl || req.url; // originalUrl gets lost in koa-connect? if (opts.autoregister && path.match(metricsMatch)) { return metricsMiddleware(req, res, next); } // bypass() is checked only after /metrics was processed // if you wish to disable /metrics use autoregister:false instead if (opts.bypass.onRequest && opts.bypass.onRequest(req)) { return next(); } if (opts.excludeRoutes && matchVsRegExps(path, opts.excludeRoutes)) { return next(); } const labels = {}; const timer = metrics[httpMetricName].startTimer(labels); onFinished(res, () => { if (opts.bypass.onFinish && opts.bypass.onFinish(req, res)) { return; } if (opts.includeStatusCode) { labels.status_code = opts.formatStatusCode(res, opts); } if (opts.includeMethod) { labels.method = req.method; } if (opts.includePath) { labels.path = opts.normalizePath instanceof Function ? opts.normalizePath(req, opts) : main.normalizePath(req, opts); } if (opts.customLabels) { Object.assign(labels, opts.customLabels); } if (opts.transformLabels) { opts.transformLabels(labels, req, res); } timer(); }); next(); }; if (opts.metricsApp) { opts.metricsApp.get(opts.metricsPath || '/metrics', (req, res) => { res.set('Content-Type', opts.promRegistry.contentType); opts.promRegistry.metrics() .then(metrics => res.end(metrics)); }); } middleware.metrics = metrics; middleware.promClient = promClient; middleware.metricsMiddleware = metricsMiddleware; return middleware; } // this is kept only for compatibility with the code relying on older version main.promClient = promClient; main.normalizePath = normalizePath; main.normalizeStatusCode = normalizeStatusCode; main.clusterMetrics = clusterMetrics; module.exports = main;