[20.05][xenial] AttributeError: 'NoneType' object has no attribute 'ver_str'

[Dmitrii Shcherbakov]

Version comparison during upgrade-charm handling fails as follows:

Traceback (most recent call last):
  File "./hooks/upgrade-charm", line 973, in <module>
    try:
  File "/var/lib/juju/agents/unit-rabbitmq-server-2/charm/charmhelpers/core/hookenv.py", line 934, in execute
    self._hooks[hook_name]()
  File "/var/lib/juju/agents/unit-rabbitmq-server-2/charm/charmhelpers/contrib/hardening/harden.py", line 93, in _harden_inner2
    return f(*args, **kwargs)
  File "./hooks/upgrade-charm", line 758, in upgrade_charm
    rabbit.cluster_with()
  File "/var/lib/juju/agents/unit-rabbitmq-server-2/charm/hooks/rabbit_utils.py", line 536, in cluster_with
    if node in running_nodes():
  File "/var/lib/juju/agents/unit-rabbitmq-server-2/charm/charmhelpers/core/hookenv.py", line 84, in wrapper
    res = func(*args, **kwargs)
  File "/var/lib/juju/agents/unit-rabbitmq-server-2/charm/hooks/rabbit_utils.py", line 833, in running_nodes
    return nodes(get_running=True)
  File "/var/lib/juju/agents/unit-rabbitmq-server-2/charm/charmhelpers/core/hookenv.py", line 84, in wrapper
    res = func(*args, **kwargs)
  File "/var/lib/juju/agents/unit-rabbitmq-server-2/charm/hooks/rabbit_utils.py", line 808, in nodes
    if caching_cmp_pkgrevno('rabbitmq-server', '3.8.2') >= 0:
  File "/var/lib/juju/agents/unit-rabbitmq-server-2/charm/charmhelpers/core/hookenv.py", line 84, in wrapper
    res = func(*args, **kwargs)
  File "/var/lib/juju/agents/unit-rabbitmq-server-2/charm/hooks/rabbit_utils.py", line 308, in caching_cmp_pkgrevno
    return cmp_pkgrevno(package, revno, pkgcache)
  File "/var/lib/juju/agents/unit-rabbitmq-server-2/charm/charmhelpers/core/host_factory/ubuntu.py", line 103, in cmp_pkgrevno
    return apt_pkg.version_compare(pkg.current_ver.ver_str, revno)
AttributeError: 'NoneType' object has no attribute 'ver_str'

[Dmitrii Shcherbakov (dmitriis)]

[10] > /var/lib/juju/agents/unit-rabbitmq-server-2/charm/hooks/rabbit_utils.py(308)caching_cmp_pkgrevno()
-> return cmp_pkgrevno(package, revno, pkgcache)
(Pdb++) s
--Call--
[11] > /var/lib/juju/agents/unit-rabbitmq-server-2/charm/charmhelpers/core/host_factory/ubuntu.py(87)cmp_pkgrevno()
-> def cmp_pkgrevno(package, revno, pkgcache=None):
(Pdb++) l
 82 :rtype: str
 83 """
 84 return lsb_release()['DISTRIB_CODENAME'].lower()
 85
 86
 87 -> def cmp_pkgrevno(package, revno, pkgcache=None):
 88 """Compare supplied revno with the revno of the installed package.
 89
 90 * 1 => Installed revno is greater than supplied arg
 91 * 0 => Installed revno is the same as supplied arg
 92 * -1 => Installed revno is less than supplied arg
(Pdb++) package
'rabbitmq-server'
(Pdb++) revno
'3.8.2'
(Pdb++) n
[11] > /var/lib/juju/agents/unit-rabbitmq-server-2/charm/charmhelpers/core/host_factory/ubuntu.py(98)cmp_pkgrevno()
-> from charmhelpers.fetch import apt_pkg
(Pdb++) n
[11] > /var/lib/juju/agents/unit-rabbitmq-server-2/charm/charmhelpers/core/host_factory/ubuntu.py(99)cmp_pkgrevno()
-> if not pkgcache:
(Pdb++) n
[11] > /var/lib/juju/agents/unit-rabbitmq-server-2/charm/charmhelpers/core/host_factory/ubuntu.py(100)cmp_pkgrevno()
-> from charmhelpers.fetch import apt_cache
(Pdb++) n
[11] > /var/lib/juju/agents/unit-rabbitmq-server-2/charm/charmhelpers/core/host_factory/ubuntu.py(101)cmp_pkgrevno()
-> pkgcache = apt_cache()
(Pdb++) n
[11] > /var/lib/juju/agents/unit-rabbitmq-server-2/charm/charmhelpers/core/host_factory/ubuntu.py(102)cmp_pkgrevno()
-> pkg = pkgcache[package]
(Pdb++) n
[11] > /var/lib/juju/agents/unit-rabbitmq-server-2/charm/charmhelpers/core/host_factory/ubuntu.py(103)cmp_pkgrevno()
-> return apt_pkg.version_compare(pkg.current_ver.ver_str, revno)
(Pdb++) pkg
{'name': 'rabbitmq-server', 'homepage': 'http://www.rabbitmq.com/', 'version': '3.5.7-1ubuntu0.16.04.2', 'sha256': 'e75f8948813db79a3d384bad7bf7ecf96a6a5ab565fa6f4095
b5d6755ac36dfd', 'depends': 'adduser, erlang-nox (>= 1:13.b.3) | esl-erlang, logrotate, init-system-helpers (>= 1.18~)', 'current_ver': None, 'bugs': 'https://bugs.la
unchpad.net/ubuntu/+filebug', 'supported': '5y', 'architecture': None, 'sha1': '3eaf4e69802ce7ecc26bad71f6f6cc46b3dbead5', 'description-md5': '78e91bfb996ee4ae5d16c93
298f5f6e8', 'filename': 'pool/main/r/rabbitmq-server/rabbitmq-server_3.5.7-1ubuntu0.16.04.2_all.deb', 'maintainer': 'Ubuntu Developers <<email address hidden>
ntu.com>', 'description-en': 'AMQP server written in Erlang\nRabbitMQ is an implementation of AMQP, the emerging standard for high\nperformance enterprise messaging.
The RabbitMQ server is a robust and\nscalable implementation of an AMQP broker.', 'installed-size': '5120', 'md5sum': '21b25f9cb60e61cb0f585c9916675426', 'priority':
'extra', 'original-maintainer': 'PKG OpenStack <email address hidden>', 'size': '4251634', 'section': 'net', 'origin': 'Ubuntu'}
(Pdb++) pkg.current_ver
(Pdb++) pkg.current_ver.ver_str
*** AttributeError: 'NoneType' object has no attribute 'ver_str'

[Dmitrii Shcherbakov (dmitriis)]

This would work on xenial:

apt_pkg.version_compare(pkg.version, revno)