Ipaddress Unicode Error

[Promaethius]

On some systems, the following error occurs resulting in cloud-init never resolving:

Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/usr/lib/python2.7/site-packages/ipaddress.py", line 163, in ip_address
    ' a unicode object?' % address)
ipaddress.AddressValueError: '172.16.4.144' does not appear to be an IPv4 or IPv6 address. Did you pass in a bytes (str in Python 2) instead of a unicode object?

[akutz]

Hi @Promaethius,

On some systems

Which systems? The function you used unicode appears to be a Python 2 built-in, but I do not see it listed for Python 3. Will this change work for Python 2 and not 3? We are trying to maintain compatibility between both versions for now. Can you please ensure any patch works for both versions of Python? Thank you.

[Promaethius]

@akutz Any Red Hat system with FIPS enabled. I have no idea why, maybe it sets a system default that python2 picks up on but this change does work. Did a comparison between RHEL7 and RHEL7 with FIPS boot option.

Using Str.encode('utf-8') method instead which should be cross compatible.

[akutz]

Hi @Promaethius,

Thank you!

Using Str.encode('utf-8') method instead which should be cross compatible.

Hmm, while it works in Python 2:

$ python2 -c 'print("hi".encode("utf-8"))'
hi

it appears the function in Python 3 returns a bytes representation of the unicode string:

$ python3 -c 'print("hi".encode("utf-8"))'
b'hi'

See if you can get it to work with both. Meanwhile I think I will conduct a poll to find out how many people are still using this with CentOS 6 and 7. It is past time to EOL support for Python 2 if we can do so with zero to marginal impact.

[Promaethius]

@akutz ok I implemented a nested exception structure that looks better than a python version check. It'll at least retry on python2 fails with a unicode string. Python3 should pass right through.

[marcusportmann]

Hello,

This fix isn't working on CentOS 7 with Python 2.7.5. I fixed it by replacing the encode call with a unicode() call in the nested exception structure.

def is_valid_ip_addr(val):
    """
    Returns false if the address is loopback, link local or unspecified;
    otherwise true is returned.
    """
    addr = None
    try:
        try:
            addr = ipaddress.ip_address(val)
        except ipaddress.AddressValueError:
            addr = ipaddress.ip_address(unicode(val))
    except:
        return False
    if addr.is_link_local or addr.is_loopback or addr.is_unspecified:
        return False
    return True