I use sar for historical, my own scripts running under cron on the hosts for specific things I’m interested in keeping an eye on and my on scripts under cron on my monitoring machines for alerting me when something’s wrong. I don’t use a dashboard.

I run Wireguard at my public VPS. I run Wireguard on my clients at home. I have Wireguard on the server configured to route via iptables, the ports I desire to send that traffic to my home machines.

This is a good resource: https://www.linuxbabe.com/ubuntu/wireguard-vpn-server-ubuntu

If this pastes correctly, here is a redacted version of my server and client config:

#
# Client (the actual self-host local server)
#
[Interface]
## This Desktop/client’s private key ##
PrivateKey =

## Client ip address ##
Address = 10.10.123.2/24

[Peer]
## Ubuntu 20.04 server public key ##
PublicKey =

## set ACL ##
#AllowedIPs = 10.10.123.0/24
# setting to 0.0.0.0/0 routes all outbound through the vpn and out the public vps
AllowedIPs = 0.0.0.0/0

## Your Ubuntu 20.04 LTS server’s public IPv4/IPv6 address and port ##
Endpoint = :12345

## Key connection alive ##
PersistentKeepalive = 15
#
# Server (in the Wireguard context, exposed to the Internet)
#
[Interface]
## My VPN server private IP address ##
Address = 10.10.123.1/24

## My VPN server port ##
ListenPort = 12345

## VPN server’s private key i.e. /etc/wireguard/privatekey ##
PrivateKey =
PostUp = iptables -i eth0 -t nat -A PREROUTING -p tcp --dport 80 -j DNAT --to-destination 10.10.123.2
PostUp = iptables -i eth0 -t nat -A PREROUTING -p tcp --dport 25 -j DNAT --to-destination 10.10.123.2
PostUp = iptables -i eth0 -t nat -A PREROUTING -p tcp --dport 443 -j DNAT --to-destination 10.10.123.2
PostUp = iptables -i eth0 -t nat -A PREROUTING -p tcp --dport 465 -j DNAT --to-destination 10.10.123.2
PostUp = iptables -i eth0 -t nat -A PREROUTING -p tcp --dport 993 -j DNAT --to-destination 10.10.123.2
PostUp = iptables -i eth0 -t nat -A PREROUTING -p tcp --dport 995 -j DNAT --to-destination 10.10.123.2
PostUp = iptables -A FORWARD -i wg0 -j ACCEPT; iptables -t nat -A POSTROUTING -o eth0 -j MASQUERADE
PostDown = iptables -i eth0 -t nat -D PREROUTING -p tcp --dport 80 -j DNAT --to-destination 10.10.123.2
PostDown = iptables -i eth0 -t nat -D PREROUTING -p tcp --dport 25 -j DNAT --to-destination 10.10.123.2
PostDown = iptables -i eth0 -t nat -D PREROUTING -p tcp --dport 443 -j DNAT --to-destination 10.10.123.2
PostDown = iptables -i eth0 -t nat -D PREROUTING -p tcp --dport 465 -j DNAT --to-destination 10.10.123.2
PostDown = iptables -i eth0 -t nat -D PREROUTING -p tcp --dport 993 -j DNAT --to-destination 10.10.123.2
PostDown = iptables -i eth0 -t nat -D PREROUTING -p tcp --dport 995 -j DNAT --to-destination 10.10.123.2
PostDown = iptables -D FORWARD -i wg0 -j ACCEPT; iptables -t nat -D POSTROUTING -o eth0 -j MASQUERADE
[Peer]
## Desktop/client VPN public key ##
PublicKey =

## client VPN IP address (note the /32 subnet) ##
AllowedIPs = 10.10.123.2/32
#
# Server - Ensure these are set in the server if using Ubuntu ufw firewall (or similar?)
#
Anywhere on ens3 ALLOW FWD Anywhere on wg0
Anywhere on wg0 ALLOW FWD Anywhere on ens3
Anywhere on wg0 ALLOW FWD Anywhere on wg0
Anywhere (v6) on ens3 ALLOW FWD Anywhere (v6) on wg0
Anywhere (v6) on wg0 ALLOW FWD Anywhere (v6) on ens3
Anywhere (v6) on wg0 ALLOW FWD Anywhere (v6) on wg0
#
# Server - Ensure ipv4 routing is on (and ipv6 if you’re using it)
#
# In /etc/sysctl.conf
net.ipv4.ip_forward=1

It looks like my favorite bug and task tool Jira can be selfhosted, if I’m reading it right: https://community.atlassian.com/t5/Jira-articles/How-to-run-Jira-in-a-docker-container/ba-p/752697

You could do what I did and move the mail server to a local machine or VM then use Wireguard on the VPS which tells iptables to route incoming mail traffic ports to the now local mail server. Then you can use as much space as you want.

Dewey decimal system IIRC from my school librarian days in the 70’s. I’d search like this:

https://github.com/topics/dewey-decimal

This might be a start:

https://github.com/SardineDude1

I’ve self-hosted for over two decades and most of the apps you mentioned I’ve not heard of or used. I self host email and my web apps and system services I wrote. I do it because I like it.