graph-image.js

const chromium = require('chrome-aws-lambda')
const { builder } = require('@netlify/functions')

async function handler(event, context) {
    // Default response.
    let response = {
        statusCode: 200,
        body: 'No image found.',
    }

    // Get asset from request path.
    let pathParts = event.path.split('/').filter((entry) => !!entry)
    const asset = pathParts[0]

    // Build page url.
    const url = process.env.URL + '/' + asset + '/?display=full'

    // Load Puppeteer.
    let browser = null
    try {
        browser = await chromium.puppeteer.launch({
            args: chromium.args,
            defaultViewport: {
                width: 1200,
                height: 630,
                deviceScaleFactor: 1,
            },
            executablePath: await chromium.executablePath,
            headless: chromium.headless,
            ignoreHTTPSErrors: true,
        })
        let page = await browser.newPage()

        // Get page.
        const loadpage = await page.goto(url)
        if (loadpage.status() == 200) {
            // Wait for chart to load.
            await page.waitForSelector('.chart-wrapper canvas', { visible: true, timeout: 5000 })

            // Add screenshot to response body.
            response.body = await page.screenshot({
                type: 'png',
                encoding: 'base64',
            })
            response.isBase64Encoded = true
            response.headers = {
                'content-type': 'image/png',
            }
        }
    } catch (error) {
        return response
    } finally {
        return response
    }
}

exports.handler = builder(handler)