Knowledge base for software setup, errors, and daily tool work.

Docker Compose Environment Variable Not Set in Dockerfile

You set an environment variable in your docker-compose.yml file, but when you try to...

Fix Chrome Black Screen During Videos: Hardware Acceleration

If you're watching a video in Chrome and the screen goes black (but audio continues), hardwar...

Fix Nginx 502 Bad Gateway on Docker Ubuntu

Cloudflare DNS Propagation Time: What to Expect and How to Check

After changing DNS records on Cloudflare, you might wonder how long it takes for the changes to t...

Fixing Cloudflare 521 Error: Origin Unreachable

When you see Cloudflare error 521, it means your origin server is refusing the connection from Cl...