If your HTTP server is running behind Cloudflare, it is recommended to only allow traffic from Cloudflare IP addresses. We can configure this systematically using iptables. However, it's also flexible to white list Cloudflare IPs just inside the Nginx service.
2020.06.15
Cloudflared is an open source golang DNS over HTTPS client developed by Cloudflare, which allow us quick start DoH for macOS system.
Although Netlify provides CDN service, Cloudflare has more edge locations around the world. What's more, Netlify hosted sites are hardly reached in China, while Cloudflare still lives. With this in mind, I decided to switch to Cloudflare for load balancing. However, pushing post/file changes to Netlify did not clear Cloudflare's cache, that's a mess. So, I'm going to use Cloudflare's API together with Netlify's outgoing webhook to make them in the same pace.
