Support upgrade: luminous -> mimic

Provide UCA mappings and upgrade path for Ceph Mimic release,
enabling upgrades on Bionic from Luminous to Mimic.

Change-Id: I73a283b86dec6a84c2a5bdfb6be5a7d263aaf070

ceph/utils.py

@@ -2540,6 +2540,7 @@ UPGRADE_PATHS = collections.OrderedDict([
     ('firefly', 'hammer'),
     ('hammer', 'jewel'),
     ('jewel', 'luminous'),
+    ('luminous', 'mimic'),
 ])
 
 # Map UCA codenames to ceph codenames
@@ -2553,6 +2554,7 @@ UCA_CODENAME_MAP = {
     'ocata': 'jewel',
     'pike': 'luminous',
     'queens': 'luminous',
+    'rocky': 'mimic',
 }
 
 

unit_tests/test_utils.py

@@ -715,6 +715,7 @@ class CephTestCase(unittest.TestCase):
             'firefly -> hammer',
             'hammer -> jewel',
             'jewel -> luminous',
+            'luminous -> mimic',
         ])
         self.assertEqual(utils.pretty_print_upgrade_paths(), expected)