storage: Add ensure_pool_is_running

We pretty much require a referenced storage pool to be running if
it's intended to be used as a virt-install or virt-manager requested
disk. So add a helper to start a pool if needed and optionally refresh
it

virtinst/cli.py

@@ -2346,6 +2346,7 @@ class ParserDisk(VirtCLIParser):
                 if poolxml:
                     poolname = poolxml.name
             poolobj = self.guest.conn.storagePoolLookupByName(poolname)
+            StoragePool.ensure_pool_is_running(poolobj)
 
         if volname:
             vol_object = poolobj.storageVolLookupByName(volname)

virtinst/diskbackend.py

@@ -17,23 +17,6 @@ import libvirt
 from .storage import StoragePool, StorageVolume
 
 
-def _lookup_pool_by_dirname(conn, path):
-    """
-    Try to find the parent pool for the passed path.
-    If found, and the pool isn't running, attempt to start it up.
-
-    return pool, or None if not found
-    """
-    pool = StoragePool.lookup_pool_by_path(conn, os.path.dirname(path))
-    if not pool:
-        return None
-
-    # Ensure pool is running
-    if pool.info()[0] != libvirt.VIR_STORAGE_POOL_RUNNING:
-        pool.create(0)
-    return pool
-
-
 def _lookup_vol_by_path(conn, path):
     """
     Try to find a volume matching the full passed path. Call info() on
@@ -96,15 +79,15 @@ def _check_if_path_managed(conn, path):
     if vol:
         return vol, vol.storagePoolLookupByVolume()
 
-    pool = _lookup_pool_by_dirname(conn, path)
+    pool = StoragePool.lookup_pool_by_path(conn, os.path.dirname(path))
     if not pool:
         return None, None
 
     # We have the parent pool, but didn't find a volume on first lookup
     # attempt. Refresh the pool and try again, in case we were just out
-    # of date.
+    # of date or the pool was inactive.
     try:
-        pool.refresh(0)
+        StoragePool.ensure_pool_is_running(pool, refresh=True)
         vol, verr = _lookup_vol_by_path(conn, path)
         if verr:
             try:

virtinst/kernelupload.py

@@ -20,7 +20,7 @@ def _build_pool(conn, meter, path):
     pool = StoragePool.lookup_pool_by_path(conn, path)
     if pool:
         logging.debug("Existing pool '%s' found for %s", pool.name(), path)
-        pool.refresh(0)
+        StoragePool.ensure_pool_is_running(pool, refresh=True)
         return pool
 
     name = StoragePool.find_free_name(conn, "boot-scratch")

virtinst/storage.py

@@ -263,6 +263,21 @@ class StoragePool(_StorageObject):
         kwargs["lib_collision"] = False
         return util.generate_name(basename, cb, **kwargs)
 
+    @staticmethod
+    def ensure_pool_is_running(pool_object, refresh=False):
+        """
+        If the passed vmmStoragePool isn't running, start it.
+
+        :param pool_object: vmmStoragePool to check/start
+        :param refresh: If True, run refresh() as well
+        """
+        if pool_object.info()[0] != libvirt.VIR_STORAGE_POOL_RUNNING:
+            logging.debug("starting pool=%s", pool_object.name())
+            pool_object.create(0)
+        if refresh:
+            logging.debug("refreshing pool=%s", pool_object.name())
+            pool_object.refresh(0)
+
 
     ######################
     # Validation helpers #
@@ -535,7 +550,7 @@ class StorageVolume(_StorageObject):
         Finds a name similar (or equal) to passed 'basename' that is not
         in use by another volume. Extra params are passed to generate_name
         """
-        pool_object.refresh(0)
+        StoragePool.ensure_pool_is_running(pool_object, refresh=True)
         return util.generate_name(basename,
                                   pool_object.storageVolLookupByName,
                                   **kwargs)
@@ -565,8 +580,7 @@ class StorageVolume(_StorageObject):
     def _get_pool(self):
         return self._pool
     def _set_pool(self, newpool):
-        if newpool.info()[0] != libvirt.VIR_STORAGE_POOL_RUNNING:
-            raise ValueError(_("pool '%s' must be active.") % newpool.name())
+        StoragePool.ensure_pool_is_running(newpool)
         self._pool = newpool
         self._pool_xml = StoragePool(self.conn,
             parsexml=self._pool.XMLDesc(0))