vegetaaaaaaa

libvirt/virt-manager is a nice VM management tool.

Their cheap 1-6€/month VPS offers are actually fine. Not much to say about it, it just works.

https://awesome-selfhosted.net/ is hosted on a Ionos VPS.

• ansible playbook for automated/self-documenting setup
• for one-off bugs or ongoing/long-term problems, open an issue on my gitea instnce and track the investigations and solutions there.

allows my mail clients to connect via IMAP to view and search emails

dovecot will be able to handle this part. This is what I use as a mail archive (once a year, archive all mail from the previous year from various mailboxes to my self-hosted dovecot instance). I wrote this ansible role for it.

downloads new emails via IMAP

As others recommended, imapsync should be able to handle that part.

docker solution

These tools are simple enough to install and manage (one package, one config file), Docker is not needed. If you really need it to fit into your docker-based setup, build and maintain your own images.

What's your existing setup? For such a simple task, check if any of the tools you use currently can be adapted (simple text files on a web server? File sharing like Nextcloud and text files? Pastebin-like? Wiki? ...). Otherwise a simple Shaarli instance could do the trick (just post "notes" aka. bookmarks without an URL). I use this theme to make it nicer. Or maybe a static site generator/blog.

I would never recommend Odoo anymore, given how painful it is to upgrade from a major version to another. Their answer to it is basically "yeah, some complex migrations need to be done, just send us a copy of your database with highly sensitive company data, pay us to do the migration and we'll send it back to you". Yeah, lol, no.

• monitoring: https://github.com/awesome-foss/awesome-sysadmin?tab=readme-ov-file#monitoring
• sending commands: https://github.com/OliveTin/OliveTin

example preseed file which I use to provision new servers (VMs)

Shaarli + stack theme

Windows Servers

No

setup automatic responses to the alerts

It should be possible using script to execute on alarm = /your/custom/remediation-script https://learn.netdata.cloud/docs/alerts-&-notifications/notifications/agent-dispatched-notifications/agent-notifications-reference. I have not experimented with this yet, but soon will (implementing a custom notification channel for specific alarms)

restarting a service if it isn’t answering requests

I'd rather find the root cause of the downtime/malfunction instead of blindly restarting the service, just my 2 cents.

I use netdata (the FOSS agent only, not the cloud offering) on all my servers (physical, VMs...) and stream all metrics to a parent netdata instance. It works extremely well for me.

Other solutions are too cumbersome and heavy on maintenance for me. You can query netdata from prometheus/grafana [1] if you really need custom dashboards.

I guess you wouldn't be able to install it on the router/switch but there is a SNMP collector which should be able to query bandwidth info from the network appliances.

• rsync + basic scripting for periodic sync, or
• distributed/replicated filesystems for real-time sync (I would start with Ceph)