Screenshot as a service

Node.js server with REST API built on top of GoogleChrome/puppeteer.

Running screenshot in Docker

cd screenshot/server
sudo docker build -t screenshot .
sudo docker run -p 8787:3000 screenshot

Set the number of browsers running in Dockerfile as an argument to server.js

REST API

Important url query param needs to be url_encoded for all endpoints

using https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/encodeURIComponent and https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/decodeURIComponent

definitions of encoding and decoding

/PNG
Query Params

• url: valid url (including https://) - required
• window: string composed of "{Int}x{Int}" - defaults to 800x600
  • the size of the browser window
• x: Int - defaults to 1
• y: Int - defaults to 1
• crop: string composed of "{Int}x{Int}" - defaults to 800x600
• waitUntil: one of the following strings
  • "load" - page loads
  • "domcontentloaded" - dom loaded
  • "networkidle0" - network is idle with 0 requests for 500ms
  • "networkidle2" - network is idle with 2 requests for 500ms Example

GET localhost:{port}/png?url=https://www.google.com&window=500x500&crop=75x80&x=350&y=190

/JPEG Query Params

• url: valid url (including https://) - required
• window: string composed of "{Int}x{Int}" - defaults to 800x600
  • the size of the browser window
• x: Int - defaults to 1
• y: Int - defaults to 1
• crop: string composed of "{Int}x{Int}" - defaults to 800x600
• waitUntil: one of the following strings
  • "load" - page loads
  • "domcontentloaded" - dom loaded
  • "networkidle0" - network is idle with 0 requests for 500ms
  • "networkidle2" - network is idle with 2 requests for 500ms
• jpegQuality: Int - 0 to 100 inclusive Example

GET localhost:{port}/jpeg?url=https://www.google.com&window=500x500&crop=75x80&x=350&y=190&jpegQuality=50

/PDF
Query Params

• url: valid url (including https://) - required
• window: string composed of "{Int}x{Int}" - defaults to 800x600
• waitUntil: one of the following strings
  • "load" - page loads
  • "domcontentloaded" - dom loaded
  • "networkidle0" - network is idle with 0 requests for 500ms
  • "networkidle2" - network is idle with 2 requests for 500ms
• format: one of the following strings
  • Letter: 8.5in x 11in
  • Legal: 8.5in x 14in
  • Tabloid: 11in x 17in
  • Ledger: 17in x 11in
  • A0: 33.1in x 46.8in
  • A1: 23.4in x 33.1in
  • A2: 16.5in x 23.4in
  • A3: 11.7in x 16.5in
  • A4: 8.27in x 11.7in
  • A5: 5.83in x 8.27in
• scale: Float - Scale of the webpage rendering. Defaults to 1.
• displayHeaderFooter: Boolean - Display header and footer. Defaults to false.
• printBackground: Boolean - Defaults to false
• landscape: Boolean - Paper orientation Defaults to false
• path: String - The file path to save the PDF to. If path is a relative path, then it is resolved relative to current working directory. If no path is provided, the PDF won't be saved to the disk. -- note this is only on the server
• pageRanges: String - Ranges to capture ex: '1-5,8,11-13' defaults to ''
• margin: in format 'top:{val};bottom:{val};left:{val};right{val}' - type of val is string ('50' or '50px' or '50%')

Example

GET localhost:{port}/pdf?url=https://www.google.com&format=Letter

result: https://www.docdroid.net/223cLO0/pdf.pdf

NOTES

crop is picked from moving the x, y from top left of the window and the crop size defines the rectangle [(x, y), (x + cropx, y), (x + cropx, y + cropy), (x, y + cropy)].

There is a rate limiter set to limit the number of requests in a 3 second window to number of browsers open (set in Dockerfile) so if 10 browsers are open and 11 requests get made within 3 seconds the 11th will fail, it will be up to the client to retry.

Each endpoint forwards the giving http headers to puppeteer so you can access pages that require auth

LICENSE

Screenshot is licensed under the MIT license. GoogleChrome/puppeteer is licensed under the Apache License 2.0.