import express from 'express' import puppeteer from 'puppeteer' const captureUrl = process.env.CAPTURE_URL || 'http://host.docker.internal:3000/' const port = process.env.PORT || 5678 const maxPages = Number(process.env.MAX_PAGES) || 5 const timeout = Number(process.env.TIMEOUT) || 10000 const cache = process.env.CACHE || 60000 const width = process.env.WIDTH || 600 const height = process.env.HEIGHT || 315 const deviceScaleFactor = process.env.SCALE_FACTOR || 2 // from https://www.bannerbear.com/blog/ways-to-speed-up-puppeteer-screenshots/ const args = [ '--autoplay-policy=user-gesture-required', '--disable-background-networking', '--disable-background-timer-throttling', '--disable-backgrounding-occluded-windows', '--disable-breakpad', '--disable-client-side-phishing-detection', '--disable-component-update', '--disable-default-apps', '--disable-dev-shm-usage', '--disable-domain-reliability', '--disable-extensions', '--disable-features=AudioServiceOutOfProcess', '--disable-hang-monitor', '--disable-ipc-flooding-protection', '--disable-notifications', '--disable-offer-store-unmasked-wallet-cards', '--disable-popup-blocking', '--disable-print-preview', '--disable-prompt-on-repost', '--disable-renderer-backgrounding', '--disable-setuid-sandbox', '--disable-speech-api', '--disable-sync', '--hide-scrollbars', '--ignore-gpu-blacklist', '--metrics-recording-only', '--mute-audio', '--no-default-browser-check', '--no-first-run', '--no-pings', '--no-sandbox', '--no-zygote', '--password-store=basic', '--use-gl=swiftshader', '--use-mock-keychain' ] let browser const app = express() app.get('/health', (req, res) => { res.status(200).end() }) app.get('/*', async (req, res) => { const url = new URL(req.originalUrl, captureUrl) const timeLabel = `${Date.now()}-${url.href}` let page, pages try { console.time(timeLabel) browser ||= await puppeteer.launch({ headless: 'new', useDataDir: './data', executablePath: 'google-chrome-stable', args, protocolTimeout: timeout, defaultViewport: { width, height, deviceScaleFactor } }) pages = (await browser.pages()).length console.timeLog(timeLabel, 'capturing', 'current pages', pages) // limit number of active pages if (pages > maxPages + 1) { console.timeLog(timeLabel, 'too many pages') return res.writeHead(503, { 'Retry-After': 1 }).end() } page = await browser.newPage() await page.emulateMediaFeatures([{ name: 'prefers-color-scheme', value: 'dark' }]) await page.goto(url.href, { waitUntil: 'load', timeout }) console.timeLog(timeLabel, 'page loaded') const file = await page.screenshot({ type: 'png', captureBeyondViewport: false }) console.timeLog(timeLabel, 'screenshot complete') res.setHeader('Content-Type', 'image/png') res.setHeader('Cache-Control', `public, max-age=${cache}, immutable, stale-while-revalidate=${cache * 24}, stale-if-error=${cache * 24}`) return res.status(200).end(file) } catch (err) { console.timeLog(timeLabel, 'error', err) return res.status(500).end() } finally { console.timeEnd(timeLabel, 'pages at start', pages) page?.close().catch(console.error) } }) app.listen(port, () => console.log(`Screenshot listen on http://:${port}`) )