How to Install Tailscale on OPNsense

Instructions

echo 'PermitRootLogin yes' >> /etc/ssh/sshd_config
service sshd restart

# Set root password
passwd

Increase the disk size of OPNsense to at least 12 GB to avoid DiskPressure and Evicted Pods issues.

df -h

# If the usage is high, add more space to the disk
# For example, to add 10 GB of space:
gpart add -s 10G -t freebsd-ufs da0
growfs /dev/da0p2

Update OPNsense to the latest version by going into the default menu via console or SSH and selecting 12. You might need to do this a few times to get to the final version.
```
opnsense-update -T opnsense-devel
```

When asked for updating to a major version, do not select 'y' as this will only cause a minor update. Type in the version number instead (it will be shown in the shell).

Additionally, enable Swap.

mdconfig -a -t swap -s 4g
swapon /dev/md0

Follow the tutorial: WireGuard mesh network using OPNsense. You can use the following command to set it up in one step (adjust IP range to your exposed IP range):
```
cd /usr/ports/security/tailscale
make install clean
service tailscaled enable
service tailscaled start
tailscale up --advertise-routes=172.16.103.1/24
```

Note: If you still encounter problems regarding missing swap, you can shut down the k3OS VM and temporarily increase the CPU and memory of OPNsense.