This is a bash script that uses curl to warm up Varnish by targeting the sitemap.xml of the website
It uses the curl package and the website should have a sitemap.xml to work.
You can pass as many URLs or IP as you want to the script like this:
$ sudo chmod +x varnish-cache-warmer.sh
$ ./varnish-cache-warmer.sh example1.com example2.com example3.com
If you happen to find something not to your liking, you are welcome to send a PR.