This quick little script can extract map tiles from an HTTP WMTS source.
Specifically, it was designed to generate a local version of the IGN 1:500k VFR charts for personal use.
It has provisions for spreading requests out in time (we're not DoS-ing, here), and using commonly expected headers (to bypass 403 errors).
MIT - Pierre Boyer, 2016.
npm install
node ign-crawler.js
# go for a walk
du -sh data/
81M data