Unable to add advertised route when using tailscale

[aacebedo]

Environmental Info:
K3s Version:
k3s version v1.32.1+k3s1 (6a322f1)
go version go1.23.5

Node(s) CPU architecture, OS, and Version:

Linux scheat 6.12.12 #1-NixOS SMP PREEMPT_DYNAMIC Sat Feb 1 17:39:40 UTC 2025 x86_64 GNU/Linux

Cluster Configuration:

1 server, 2 agents
Describe the bug:

Route advertised by tailscale cannot be modified. I added a route to extraArgs of vpnAuth arg but it is replaced by k3s because it executes a PostStartupCommand containing tailscale set with a $SUBNET variable. I do not know how to modify this var but it overwrites the argument given in the extraArgs.

Steps To Reproduce:

• Installed K3s:
• add extraArgs to vpnAuth with --advertised-routes arg

Expected behavior:

advertised routes contains the values given in extraArgs

Actual behavior:

advertised routes only contains k3s subnet

Additional context / logs: