net.is_ip_address could not solve ipv6 has URL encode %25

[volehuy1998]

Bug report

Cloud-init is not possible with IPv6 because the net.is_ip_address function cannot resolve fe80::a9fe:a9fe%25{iface}, instead of fe80::a9fe:a9fe%{iface}. Leading to the removal of IPv6 from the metadata retrieval list.

# cloudinit/sources/DataSourceOpenStack.py
DEF_MD_URLS = [
            "http://[fe80::a9fe:a9fe%25{iface}]".format(
                iface=self.distro.fallback_interface
            ),
            "http://169.254.169.254",
        ]

# cloudinit/util.py
with suppress(ValueError):
            if net.is_ip_address(parsed_url.netloc.strip("[]")):
                return True

Fix by

# cloudinit/sources/DataSourceOpenStack.py
DEF_MD_URLS = [
            "http://[fe80::a9fe:a9fe%{iface}]".format(
                iface=self.distro.fallback_interface
            ),
            "http://169.254.169.254",
        ]

# cloudinit/util.py
with suppress(ValueError):
            if net.is_ip_address(parsed_url.netloc.strip("[]")):
                return True

Steps to reproduce the problem

$ cloud-init init

Environment details

• Cloud-init version: 24.3.1-0ubuntu0~20.04.1
• Operating System Distribution: ubuntu 20.04
• Cloud provider, platform or installer type: OpenStack