The disk that filled itself
Homelab box said 100 percent full, du said half the disk was free. Docker was holding open a log file I had rm'd months ago. lsof +L1 untangles the knot.
The Sentry signup nobody could finish
A colleague signed up on our self-hosted Sentry and never got the email. I had been getting Sentry mail forever, so I assumed he was missing something. He was not. DMARC was silently dropping every message to our Workspace inboxes, and the 'workaround' I shared with him broke too. Here is the bug, the lie my inbox had been telling me, and the shell command that finally got him in.
I upgraded our 2.5-year-old self-hosted Sentry without losing a single byte
A self-hosted Sentry instance, 2.5 years behind, 0 bytes of swap free, 4 mandatory version hops, 78 containers, and one afternoon where I learned that enabling a feature and using a feature are not the same thing.