Today I’ve got this error

SysctlForbidden kubelet forbidden sysctl: "net.ipv6.conf.all.disable_ipv6" not whitelisted

Rancher desktop will not accept all sysctls. Some are allowed, but most options are not. To get this working you have to add the setting to the allowed-unsafe-sysctls list.

podSecurityContext:                        
  sysctls:                                 
    - name: net.ipv6.conf.all.disable_ipv6 
      value: '1' 

⭐️ Tip: you can see hidden files in Finder on Mac by pressing CMD + Shift + .

Open ~/library/Application Support/rancher-desktop/lima/_config/override.yaml and add the extra options to K3S_EXEC. Be sure to specify the complete value since the setting is overwritten not appended. Use commas with multiple values.

In the example below I’ve added the option to specify net.ipv6.conf.all.disable_ipv6 next to the default setting values net.ipv4.ip_forward and net.ipv6.conf.all.forwarding. Scroll horizontal to see everything.

env:
  K3S_EXEC: --kubelet-arg=allowed-unsafe-sysctls=net.ipv4.ip_forward,net.ipv6.conf.all.forwarding,net.ipv6.conf.all.disable_ipv6

You can validate the change has been applied by looking at the logfile ~/Library/Logs/rancher-desktop/k3s.log. Here you can find the “default” value before you change it with the override.yaml edit above.

time="2023-12-01T11:35:33Z" level=info msg="Running kubelet --address=0.0.0.0 --allowed-unsafe-sysctls=net.ipv4.ip_forward,net.ipv6.conf.all.forwarding,net.ipv6.conf.all.disable_ipv6 --anonymous-auth=false

References

https://docs.rancherdesktop.io/how-to-guides/provisioning-scripts/