Comment 1 for bug 1951094

# A dict of valid ceph upgrade paths. Mapping is old -> new
UPGRADE_PATHS = collections.OrderedDict([
    ('firefly', 'hammer'),
    ('hammer', 'jewel'),
    ('jewel', 'luminous'),
    ('luminous', 'mimic'),
    ('mimic', 'nautilus'),
    ('nautilus', 'octopus'),
])

# Map UCA codenames to ceph codenames
UCA_CODENAME_MAP = {
    'icehouse': 'firefly',
    'juno': 'firefly',
    'kilo': 'hammer',
    'liberty': 'hammer',
    'mitaka': 'jewel',
    'newton': 'jewel',
    'ocata': 'jewel',
    'pike': 'luminous',
    'queens': 'luminous',
    'rocky': 'mimic',
    'stein': 'mimic',
    'train': 'nautilus',
    'ussuri': 'octopus',
}

releases past ussuri need to be added to charms.ceph to support upgrades.