Ask HN: Tool suggestions for keeping track of your servers?

Can you recommend an online tool (preferably free, or possibly self-hosted), that is not an Excel spreadsheet or Google Doc, which is capable of helping keep track of the servers I have, and the services I run on them (domains + subdomains + possible other micro-service detail-information)?

I have about 9 - 12 servers (and a few custom-VPNs) with various providers, some are actual hardware servers, others are cheap virtual servers or AWS instances or buckets.

Then, I have lots of smaller and larger projects distributed across those servers. Some are just 1 service / 1 server, others are distributed across several servers and need each other to work.

Not everything's super reboot-safe and automated with god and such, the smaller micro-service things aren't as uptime-monitored as the bigger sites on those machines.

Now with the reboots of spectre/meltdown fixes, I am basically getting a lot of "random server name is being rebooted today!"or "ip such and such has been forced to reboot" — and now I am having to log in to each and every server to see if things booted back up, and what is actually running where (I keep losing track of the smaller things from time to time).

Something that'd let me document all of this before the new year speeds up again would be great!

I use uptimerobot — but that's just for the things I care to monitor.