Docker images quietly filled my disk until every service on my VPS went down

I run a few small apps on a VPS with Dokploy. At some point the automatic Docker image cleanup got disabled, I still don't know exactly when or why. Every time I pushed to GitHub and something redeployed, the old images just piled up instead of getting cleaned. Slowly, silently, the disk kept filling.

Eventually it hit 100%. Every service on that box went down at once. No disk space left for anything to even write logs properly.

I had no idea. I found out almost a full day later because I'd signed up for UptimeRobot months earlier on a whim and added one free monitor. It pinged me, I logged in, saw the disk was maxed out, cleared some space, and everything came back up.

The part that actually scares me: without that one free monitor, I might not have noticed until a user emailed me or worse, not noticed at all for days.

It made me realize how many of us ship stuff and just assume it stays up. No monitoring, no alerting, nothing. One disabled cron job and you're down for a day and don't even know it.

Curious how other people here handle this

do you have monitoring set up on your side projects, or are you also one angry DM away from finding out something's broken?