Upgrade configuration wrt enabled storage types

This implements an online update of the configuration for when a configuration
is loaded that does not yet contain the 'enabled_storage_types' attribute.
Note that this will require more changes as dis/enabling of (shared) file
storage at configure time will be removed.
This patch includes adding a mapping from disk templates to storage types. While
I was on it, I also reordered the disk template and storage type parameters
alphabetically, to make dealing with those easier.
Also, this mentions the configuration change in the NEWS file.

Signed-off-by: Helga Velroyen <helgav@google.com>
Reviewed-by: Guido Trotter <ultrotter@google.com>

diff --git a/NEWS b/NEWS
index dd823c0..09fc29e 100644 (file)
--- a/NEWS
+++ b/NEWS
@@ -11,6 +11,13 @@ Version 2.8.0 beta1
 - The :doc:`Remote API <rapi>` daemon now supports a command line flag
   to always require authentication, ``--require-authentication``. It can
   be specified in ``$sysconfdir/default/ganeti``.
+- A new cluster attribute 'enabled_storage_types' is introduced. It will
+  be used to manage the storage types to be used by instances in the cluster.
+  Initially, it will be set to a list that includes lvm, file and sharedfile
+  if those are enabled. Additionally, it will include all storage types that
+  are currently used by instances. The order of storage types will be based
+  on Ganeti's history of supporting them. In the future, the first entry of
+  the list will be used as a default storage type on instance creation.
 
 
 Version 2.7.0 beta1

diff --git a/lib/constants.py b/lib/constants.py
index 458ee2c..5a4e465 100644 (file)
--- a/lib/constants.py
+++ b/lib/constants.py
@@ -373,24 +373,24 @@ HKR_FAIL = 1
 HKR_SUCCESS = 2
 
 # Storage types
+ST_BLOCK = "blockdev"
+ST_DISKLESS = "diskless"
+ST_EXT = "ext"
 ST_FILE = "file"
 ST_LVM_PV = "lvm-pv"
 ST_LVM_VG = "lvm-vg"
-ST_DISKLESS = "diskless"
-ST_SHARED_FILE = "sharedfile"
-ST_BLOCK = "blockdev"
 ST_RADOS = "rados"
-ST_EXT = "ext"
+ST_SHARED_FILE = "sharedfile"
 
 VALID_STORAGE_TYPES = compat.UniqueFrozenset([
+  ST_BLOCK,
+  ST_DISKLESS,
+  ST_EXT,
   ST_FILE,
   ST_LVM_PV,
   ST_LVM_VG,
-  ST_DISKLESS,
-  ST_SHARED_FILE,
-  ST_BLOCK,
   ST_RADOS,
-  ST_EXT,
+  ST_SHARED_FILE,
   ])
 
 # Per default, only lvm is enabled.
@@ -398,6 +398,18 @@ DEFAULT_ENABLED_STORAGE_TYPES = compat.UniqueFrozenset([
   ST_LVM_VG,
   ])
 
+# This is used to order determine the default storage type when the list
+# of enabled storage types is inferred from the current state of the cluster.
+# This only happens on an upgrade from a version of Ganeti that did not
+# support the 'enabled_storage_methods' so far.
+STORAGE_TYPES_PREFERENCE = [
+  ST_LVM_VG,
+  ST_FILE,
+  ST_SHARED_FILE,
+  ST_RADOS,
+  ST_BLOCK,
+  ]
+
 # Storage fields
 # first two are valid in LU context only, not passed to backend
 SF_NODE = "node"
@@ -437,14 +449,26 @@ VALID_STORAGE_OPERATIONS = {
  LDS_FAULTY) = range(1, 4)
 
 # disk template types
+DT_BLOCK = "blockdev"
 DT_DISKLESS = "diskless"
-DT_PLAIN = "plain"
 DT_DRBD8 = "drbd"
+DT_EXT = "ext"
 DT_FILE = "file"
-DT_SHARED_FILE = "sharedfile"
-DT_BLOCK = "blockdev"
+DT_PLAIN = "plain"
 DT_RBD = "rbd"
-DT_EXT = "ext"
+DT_SHARED_FILE = "sharedfile"
+
+# mapping of disk templates to storage types
+DISK_TEMPLATES_STORAGE_TYPE = {
+  DT_BLOCK: ST_BLOCK,
+  DT_DISKLESS: ST_DISKLESS,
+  DT_DRBD8: ST_LVM_VG,
+  DT_EXT: ST_EXT,
+  DT_FILE: ST_FILE,
+  DT_PLAIN: ST_LVM_VG,
+  DT_RBD: ST_RADOS,
+  DT_SHARED_FILE: ST_SHARED_FILE,
+  }
 
 # the set of network-mirrored disk templates
 DTS_INT_MIRROR = compat.UniqueFrozenset([DT_DRBD8])

diff --git a/lib/objects.py b/lib/objects.py
index 2fdf7bc..782dacc 100644 (file)
--- a/lib/objects.py
+++ b/lib/objects.py
@@ -463,6 +463,37 @@ class ConfigData(ConfigObject):
       self.networks = {}
     for network in self.networks.values():
       network.UpgradeConfig()
+    self._UpgradeStorageTypes()
+
+  def _UpgradeStorageTypes(self):
+    """Upgrade the cluster's enabled storage types by inspecting the currently
+       enabled and/or used storage types.
+
+    """
+    # enabled_storage_types in the cluster config were introduced in 2.8. Remove
+    # this code once upgrading from earlier versions is deprecated.
+    if not self.cluster.enabled_storage_types:
+      storage_type_set = \
+        set([constants.DISK_TEMPLATES_STORAGE_TYPE[inst.disk_template]
+               for inst in self.instances.values()])
+      # Add lvm, file and shared file storage, if they are enabled, even though
+      # they might currently not be used.
+      if self.cluster.volume_group_name:
+        storage_type_set.add(constants.ST_LVM_VG)
+      # FIXME: Adapt this when dis/enabling at configure time is removed.
+      if constants.ENABLE_FILE_STORAGE:
+        storage_type_set.add(constants.ST_FILE)
+      if constants.ENABLE_SHARED_FILE_STORAGE:
+        storage_type_set.add(constants.ST_SHARED_FILE)
+      # Set enabled_storage_types to the inferred storage types. Order them
+      # according to a preference list that is based on Ganeti's history of
+      # supported storage types.
+      self.cluster.enabled_storage_types = []
+      for preferred_type in constants.STORAGE_TYPES_PREFERENCE:
+        if preferred_type in storage_type_set:
+          self.cluster.enabled_storage_types.append(preferred_type)
+          storage_type_set.remove(preferred_type)
+      self.cluster.enabled_storage_types.extend(list(storage_type_set))
 
 
 class NIC(ConfigObject):