Allow lookup of pool by name only.

library/blivet.py

@@ -704,7 +704,7 @@ def _type_check(self):  # pylint: disable=no-self-use
 
     def _look_up_disks(self):
         """ Look up the pool's disks in blivet's device tree. """
-        if not self._pool['disks']:
+        if not self._device and not self._pool['disks']:
             raise BlivetAnsibleError("no disks specified for pool '%s'" % self._pool['name'])
         elif not isinstance(self._pool['disks'], list):
             raise BlivetAnsibleError("pool disks must be specified as a list")
@@ -715,7 +715,7 @@ def _look_up_disks(self):
             if device is not None:  # XXX fail if any disk isn't resolved?
                 disks.append(device)
 
-        if self._pool['disks'] and not disks:
+        if self._pool['disks'] and not self._device and not disks:
             raise BlivetAnsibleError("unable to resolve any disks specified for pool '%s' (%s)" % (self._pool['name'], self._pool['disks']))
 
         self._disks = disks
@@ -820,9 +820,9 @@ def _manage_volumes(self):
     def manage(self):
         """ Schedule actions to configure this pool according to the yaml input. """
         # look up the device
-        self._look_up_disks()
         self._look_up_device()
         self._apply_defaults()
+        self._look_up_disks()
 
         # schedule destroy if appropriate, including member type change
         if not self.ultimately_present or self._member_management_is_destructive():

tests/test-verify-pool-members.yml

@@ -24,7 +24,7 @@
   assert:
     that: "{{ ansible_lvm.pvs|dict2items|json_query('[?value.vg==`\"{}\"`]'.format(storage_test_pool.name))|length == _storage_test_expected_pv_count|int }}"
     msg: "Unexpected PV count for pool {{ storage_test_pool.name }}"
-  when: storage_test_pool.type == 'lvm'
+  when: storage_test_pool.type == 'lvm' and storage_test_pool.disks
 
 - set_fact:
     _storage_test_expected_pv_type: "{{ 'crypt' if storage_test_pool.encryption else 'disk' }}"

tests/tests_existing_lvm_pool.yml

@@ -0,0 +1,54 @@
+---
+- hosts: all
+  become: true
+  vars:
+    mount_location: '/opt/test1'
+    volume_group_size: '5g'
+    volume_size: '4g'
+    pool_name: foo
+
+  tasks:
+    - include_role:
+        name: storage
+
+    - include_tasks: get_unused_disk.yml
+      vars:
+        min_size: "{{ volume_group_size }}"
+        max_return: 1
+
+    - name: Create one LVM logical volume under one volume group
+      include_role:
+        name: storage
+      vars:
+          storage_pools:
+            - name: "{{ pool_name }}"
+              disks: "{{ unused_disks }}"
+              volumes:
+                - name: test1
+                  size: "{{ volume_size }}"
+
+    - include_tasks: verify-role-results.yml
+
+    - name: Create another volume in the existing pool, identified only by name.
+      include_role:
+        name: storage
+      vars:
+        storage_pools:
+          - name: "{{ pool_name }}"
+            volumes:
+              - name: newvol
+                size: '2 GiB'
+                fs_type: ext4
+                fs_label: newvol
+
+    - include_tasks: verify-role-results.yml
+
+    - name: Clean up.
+      include_role:
+        name: storage
+      vars:
+        storage_pools:
+          - name: "{{ pool_name }}"
+            state: absent
+
+    - include_tasks: verify-role-results.yml