fix(storages): a new directory pool starts when its directory does not exist

create_storage built only logical pools, so a dir pool whose target path
was missing failed to start ("cannot open directory"): the page showed the
libvirt error and the pool stayed defined, inactive and without autostart.
The pool is now started with VIR_STORAGE_POOL_CREATE_WITH_BUILD, which
makes the directory, or for a logical pool the volume group as the
separate build call did.

A live test creates a dir pool at a missing path on the storages page;
the LVM live test still creates its logical pool the same way.

storages/tests/test_live_pools.py

@@ -0,0 +1,53 @@
+"""Live check that a directory pool created on the storages page starts
+when its directory does not exist yet: libvirt builds it. Runs only with
+TEST_LIBVIRT_HOST set."""
+
+import os
+import unittest
+
+import libvirt
+from computes.models import Compute
+from django.contrib.auth import get_user_model
+from django.test import TestCase
+from django.urls import reverse
+from instances.tests import livetest
+from vrtManager.connection import connection_manager
+
+POOL = livetest.PREFIX + "dir"
+PATH = f"/var/lib/libvirt/{POOL}"
+
+
+@unittest.skipUnless(livetest.enabled(), "Set TEST_LIBVIRT_HOST to run the live libvirt tests")
+class LivePoolsTestCase(TestCase):
+    def setUp(self):
+        args = dict(
+            hostname=os.environ["TEST_LIBVIRT_HOST"],
+            login=os.environ.get("TEST_LIBVIRT_LOGIN", ""),
+            password=os.environ.get("TEST_LIBVIRT_PASSWORD", ""),
+            type=int(os.environ.get("TEST_LIBVIRT_TYPE", 1)),
+        )
+        self.conn = connection_manager.get_connection(*args.values())
+        self.remove_pool()
+        self.addCleanup(self.remove_pool)
+        self.compute = Compute.objects.create(name="live-pools", **args)
+        self.client.force_login(get_user_model().objects.create_superuser("live-pools", "lp@example.com", "x"))
+
+    def remove_pool(self):
+        try:
+            pool = self.conn.storagePoolLookupByName(POOL)
+        except libvirt.libvirtError:
+            return
+        if pool.isActive():
+            pool.destroy()
+            pool.delete(0)  # removes the directory
+        pool.undefine()
+
+    def test_a_missing_directory_is_built(self):
+        response = self.client.post(
+            reverse("storages", args=[self.compute.id]),
+            {"create": "", "name": POOL, "stg_type": "dir", "target": PATH},
+        )
+        self.assertRedirects(response, reverse("storage", args=[self.compute.id, POOL]), fetch_redirect_response=False)
+        pool = self.conn.storagePoolLookupByName(POOL)
+        self.assertTrue(pool.isActive())
+        self.assertTrue(pool.autostart())

vrtManager/storage.py

@@ -1,5 +1,6 @@
 import contextlib
 
+import libvirt
 from vrtManager import util
 from vrtManager.connection import wvmConnect
 
@@ -56,9 +57,8 @@ class wvmStorages(wvmConnect):
                 </pool>"""
         self.define_storage(xml, 0)
         stg = self.get_storage(name)
-        if stg_type == "logical":
-            stg.build(0)
-        stg.create(0)
+        # builds the dir pool's directory or the logical pool's volume group
+        stg.create(libvirt.VIR_STORAGE_POOL_CREATE_WITH_BUILD)
         stg.setAutostart(1)
 
         return stg