Add support for IPv6 addresses

CC007 commented 1 year ago

Why do you need this?

My node only has a reachable IPv6 address, so I tried to use k3sup with the following command:

k3sup install --context <cluster context> --user <vm user> --ip <IPv6>

Expected Behaviour

I expect this to work the same way as for an IPv4 address

Current Behaviour

I get the following output:

Running: k3sup install
2022/12/24 xx:xx:xx <IPv6>
Public IP: <IPv6>
Error: unable to connect to <IPv6> over ssh: dial tcp: address <IPv6>:22: too many colons in address

Possible Solution

Add a -6 flag for when the user wants to provide an IPv6 address. In such cases it might also be needed to specify the network adapter, like <IPv6>%eth0. This seems to be the case for ssh, but not for ping, so you'd have to check if you need this.

Steps to Reproduce

Download k3sup
Run k3sup install --context <cluster context> --user <vm user> --ip <IPv6> (with everything between <> filled in ofc.)

Your Environment

k3sup version:

0.12.12

What Kubernetes distribution, client and server version are you using?

N/A

What OS or type or VM are you using for your cluster? Where is it hosted? (for k3sup install/join):
Operating System and version (e.g. Linux, Windows, MacOS):

Self-hosted. 
Host OS: Windows 11 22H2 (build: 22621.963), using Hyper-V (Configuration version: 11.0) + multipass (for creating the VMs)

VM OS instances: 
Linux <vmname> 5.15.0-56-generic #62-Ubuntu SMP Tue Nov 22 19:54:14 UTC 2022 x86_64 x86_64 x86_64 GNU/Linux

PRETTY_NAME="Ubuntu 22.04.1 LTS"
NAME="Ubuntu"
VERSION_ID="22.04"
VERSION="22.04.1 LTS (Jammy Jellyfish)"
VERSION_CODENAME=jammy
ID=ubuntu
ID_LIKE=debian
HOME_URL="https://www.ubuntu.com/"
SUPPORT_URL="https://help.ubuntu.com/"
BUG_REPORT_URL="https://bugs.launchpad.net/ubuntu/"
PRIVACY_POLICY_URL="https://www.ubuntu.com/legal/terms-and-policies/privacy-policy"
UBUNTU_CODENAME=jammy

Do you want to work on this?

Subject to design approval, are you willing to work on a Pull Request for this issue or feature request?

I would be willing, but I don't have very much experience with GoLang.

alexellis commented 1 year ago

Hi, have you tried --host instead of --ip?

CC007 commented 1 year ago

With --host I get the same error.

I also tried --host with the <vmname>.mshome.net, but since this is from inside WSL2, the DNS doesn't resolve.

Charlio99 commented 1 year ago

I would be also interested in this. Most of VPS servers are quite cheaper when paying for IPv6 only

Charlio99 commented 1 year ago

I have no idea on the matter because I don't know much about the ssh library in go, but in a quick search I found this: https://github.com/kubernetes/minikube/pull/625 and https://github.com/kubernetes/minikube/pull/6110 they used to solve the same error in minikube

alexellis commented 1 year ago

Thanks for your interest @Charlio99

How cheap is your IPv6-only VPS?

DO and Scaleway have VMs for 3-5 EUR/USD/mo.

Is it cheaper than that? And is that the only driver here?

Charlio99 commented 1 year ago

Hello @alexellis,

The price difference it’s 1,7EUR/mo in the 1vCPU 2GB RAM config, the thing is that if I spin up 3 clusters with 3 workers 1 cp each, it’s 20EUR/month I could be having almost 2 clusters more for that.

Given that the main purpose of k3sup is to quickly spin up a k3s cluster, I think this is the ideal scenario.

I would be willing to help implement it but I never used go before.

CC007 commented 1 year ago

I'm not in the position to test right now, since I fully changed my k8s server setup to harvester/rancher, rather than Windows+hyperv/multipass/k3sup, but I didn't test back then if ipv6 worked if you put square brackets around the address, similar to how you go to ipv6 addresses in the browser.

@Charlio99 , could you test that?

Charlio99 commented 1 year ago

I tried that also, I did some more debugging today and it seems that github.com is a non IPv6 domain, so when get.k3s.io tried to fetch the last version, it can't...

$ nslookup github.com
Server:     2606:4700:4700::1111
Address:    2606:4700:4700::1111#53

Non-authoritative answer:
Name:   github.com
Address: 140.82.121.4

Charlio99 commented 1 year ago

I found a way around, I've created this PR, it's a simple change to the docs explaining how to do it, feel free to edit anything you want.

CC007 commented 1 year ago

Great work!

alexellis / k3sup