I’ve dabbled with some monitoring tools in the past, but never really stuck with anything proper for very long. I usually notice issues myself. I self-host my own custom new-tab page that I use across all my devices and between that, Nextcloud clients, and my home-assistant reverse proxy on the same vps, when I do have unexpected downtime, I usually notice within a few minutes.

Other than that I run fail2ban, and have my vps configured to send me a text message/notification whenever someone successfully logs in to a shell via ssh, just in case.

Based on the logs over the years, most bots that try to login try with usernames like admin or root, I have root login disabled for ssh, and the one account that can be used over ssh has a non-obvious username that would also have to be guessed before an attacker could even try passwords, and fail2ban does a good job of blocking ips that fail after a few tries.

If I used containers, I would probably want a way to monitor them, but I personally dislike containers (for myself, I’m not here to “yuck” anyone’s “yum”) and deliberately avoid them.