Check for lxd ipv6 is failing for various cases

[Christian Ehrhardt ]

While debugging an issue with juju on lxd always running into an error like:
ERROR creating LXD client: juju doesn't support ipv6. Please disable LXD's IPV6

Yet we have disabled ipv6 in LXD.
In newer LXd that is rather easy via:
$ lxc network edit lxdbr0

If you delete all ipv6 statements there that is pretty much the same as if you would have done
$ sudo lxd init
And did not enable ipv6 there.

But, the check of today in juju expects the format to be exactly as the script places it, which is:
ipv6.address: none

BUT, that is no hard requirement.

For now as a workaround you can add that line "ipv6.address: none" into your lxd network config.
That makes juju happy.

But eventually juju should fix the check for ipv6 network to not check for that explicit value.

[Christian Ehrhardt  (paelzer)]

As just discussed, also the message might be improved as on newer lxd reconfiguring can be done as shown above.

Since the currently recommended "sudo lxd init" forces users to delete all containers and images that is something people don't like. But with newer lxd this could be:
"You can do do by removing all ipv6 from lxc network edit lxdbr0"

If you happen to know the name of the bridge in juju insert the right name in the message.

[Horacio Durán (hduran-8)]

I proposed https://github.com/juju/juju/pull/6916