ganeti_web/caps.py

   1 """
   2 Capabilities for clusters.
   3
   4 This module can classify clusters into a capability group, and provides some
   5 helpful utility functions for determining what clusters are capable of doing.
   6
   7 Versions recognized by this module (and GWM at large):
   8
   9  * ANCIENT: Ganeti from before the dawn of time. Ganeti 2.1 and earlier, as
  10    well as any unrecognized versions.
  11  * GANETI22: Ganeti 2.2.x
  12  * GANETI23: Ganeti 2.3.x
  13  * GANETI24: Ganeti 2.4.x prior to 2.4.2
  14  * GANETI242: Ganeti 2.4.2 and newer in the 2.4.x series
  15  * GANETI25: Ganeti 2.5.x
  16  * GANETI26: Ganeti 2.6.x
  17  * FUTURE: Ganeti which probably is newer than, and somewhat
  18    backwards-compatible with, the newest version of Ganeti which GWM
  19    officially supports.
  20
  21 Note that all bets are off if the cluster's version doesn't correspond to the
  22 x.y.z (major.minor.patch) versioning pattern.
  23 """
  24
  25 (
  26     ANCIENT,
  27     GANETI22,
  28     GANETI23,
  29     GANETI24,
  30     GANETI242,
  31     GANETI25,
  32     GANETI26,
  33     FUTURE,
  34 ) = range(8)
  35
  36
  37 def classify(cluster):
  38     """
  39     Determine the class of a cluster by examining its version.
  40     """
  41
  42     # Extract the version string from the cluster.
  43     s = cluster.info["software_version"]
  44
  45     # First, try the whole splitting thing. If we can't do it that way, assume
  46     # it's ancient.
  47     try:
  48         version = tuple(int(x) for x in s.split("."))
  49     except ValueError:
  50         return ANCIENT
  51
  52     if version >= (2, 7, 0):
  53         return FUTURE
  54     if version >= (2, 6, 0):
  55         return GANETI26
  56     elif version >= (2, 5, 0):
  57         return GANETI25
  58     elif version >= (2, 4, 2):
  59         return GANETI242
  60     elif version >= (2, 4, 0):
  61         return GANETI24
  62     elif version >= (2, 3, 0):
  63         return GANETI23
  64     elif version >= (2, 2, 0):
  65         return GANETI22
  66     else:
  67         return ANCIENT
  68
  69
  70 def has_shutdown_timeout(cluster):
  71     """
  72     Determine whether a cluster supports timeouts for shutting down VMs.
  73     """
  74
  75     return classify(cluster) >= GANETI25
  76
  77
  78 def has_cdrom2(cluster):
  79     """
  80     Determine whether a cluster supports a second CDROM device.
  81     """
  82
  83     return classify(cluster) >= GANETI242
  84
  85
  86 def has_balloonmem(cluster):
  87     """
  88     Determine whether a cluster requires min/maxmem rather than
  89     just memory.
  90     """
  91
  92     return classify(cluster) >= GANETI26
  93
  94
  95 def has_sharedfile(cluster):
  96     """
  97     Determine whether a cluster supports the sharedfile disk template.
  98     """
  99
 100     return classify(cluster) >= GANETI25