fix: Show better error when trying to create RAID w/o enough disks

Resolves: RHEL-95757

Author: vojtechtrefny

library/blivet.py

@@ -389,6 +389,7 @@
     from blivet3 import devices
     from blivet3.deviceaction import ActionConfigureFormat, ActionResizeFormat, ActionAddMember, ActionRemoveMember
     from blivet3.devicefactory import DEFAULT_THPOOL_RESERVE
+    from blivet3.errors import RaidError
     from blivet3.flags import flags as blivet_flags
     from blivet3.formats import fslib, get_format
     from blivet3.partitioning import do_partitioning
@@ -405,6 +406,7 @@
         from blivet import devices
         from blivet.deviceaction import ActionConfigureFormat, ActionResizeFormat, ActionAddMember, ActionRemoveMember
         from blivet.devicefactory import DEFAULT_THPOOL_RESERVE
+        from blivet.errors import RaidError
         from blivet.flags import flags as blivet_flags
         from blivet.formats import fslib, get_format
         from blivet.partitioning import do_partitioning
@@ -538,6 +540,17 @@ def _new_mdarray(self, members, raid_name=""):
         if raid_name == "":
             raid_name = self._spec_dict["name"]
 
+
+        raid_level = self._spec_dict["raid_level"]
+        try:
+            blivet_level = devicelibs.raid.get_raid_level(raid_level)
+        except RaidError:
+            raise BlivetAnsibleError("%s is not a valid RAID level" % raid_level)
+        else:
+            if len(members) < blivet_level.min_members:
+                raise BlivetAnsibleError("not enough disks selected to create %s array, at least %d "
+                                         "disks needed" % (raid_level, blivet_level.min_members))
+
         # calculate and verify active and spare devices counts
         active_count = len(members)
         spare_count = 0
@@ -571,7 +584,7 @@ def _new_mdarray(self, members, raid_name=""):
 
         try:
             raid_array = self._blivet.new_mdarray(name=raid_name,
-                                                  level=self._spec_dict["raid_level"],
+                                                  level=raid_level,
                                                   member_devices=active_count,
                                                   total_devices=len(members),
                                                   parents=members,

tests/tests_fatals_raid_pool.yml

@@ -37,6 +37,10 @@
     - name: Try to create a raid pool with invalid raid_level (expect failure)
       include_tasks: verify-role-failed.yml
       vars:
+        __storage_failed_regex: >-
+          fail is not a valid RAID level
+        __storage_failed_msg: >-
+          Unexpected behavior w/ invalid RAID level
         __storage_failed_params:
           storage_pools:
             - name: vg1
@@ -54,3 +58,28 @@
                 - name: lv3
                   size: "{{ volume3_size }}"
                   mount_point: "{{ mount_location3 }}"
+
+    - name: Try to create a raid pool without enough disks (expect failure)
+      include_tasks: verify-role-failed.yml
+      vars:
+        __storage_failed_regex: >-
+          not enough disks selected to create raid5 array, at least 3 disks needed
+        __storage_failed_msg: >-
+          Unexpected behavior w/ invalid number of disks
+        __storage_failed_params:
+          storage_pools:
+            - name: vg1
+              disks: "{{ unused_disks }}"
+              type: lvm
+              raid_level: raid5
+              state: present
+              volumes:
+                - name: lv1
+                  size: "{{ volume1_size }}"
+                  mount_point: "{{ mount_location1 }}"
+                - name: lv2
+                  size: "{{ volume2_size }}"
+                  mount_point: "{{ mount_location2 }}"
+                - name: lv3
+                  size: "{{ volume3_size }}"
+                  mount_point: "{{ mount_location3 }}"