copr-backend: scripts for listing and removing LibVirt domains

Previous approach was causing some volume leftovers.

roles/copr/backend/files/provision/libvirt-delete

@@ -0,0 +1,73 @@
+#! /usr/bin/python3
+
+"""
+Delete the given Resalloc-related LibVirt domain (and the related resources)
+"""
+
+# pylint: disable=broad-except
+
+import argparse
+import logging
+import time
+
+import libvirt
+
+def repeat(call, args):
+    """ Repeat the given function call, with args """
+    attempts = 3
+    for attempt in range(1, attempts+1):
+        try:
+            return call(*args)
+        except Exception:
+            seconds = 10
+            if attempt < attempts:
+                logging.exception("Failed repeatable call, sleep %ss",
+                                  seconds)
+                time.sleep(seconds)
+                continue
+            raise
+
+def _get_parser():
+    parser = argparse.ArgumentParser()
+    parser.add_argument("--connection", required=True)
+    parser.add_argument("domainname")
+    return parser
+
+def _delete_domain(domain):
+    try:
+        domain.destroy()
+        logging.info("Domain %s destroyed", domain.name())
+    except Exception:
+        logging.exception("can't destroy %s", domain.name())
+
+    domain.undefine()
+    logging.info("Domain %s undefined", domain.name())
+
+def _delete_volume(pool, volume_name):
+    volume = pool.storageVolLookupByName(volume_name)
+    volume.delete()
+
+
+def _main():
+    logging.basicConfig(level=logging.INFO)
+    args = _get_parser().parse_args()
+    conn = repeat(libvirt.open, (args.connection,))
+    try:
+        domain = repeat(conn.lookupByName, (args.domainname,))
+        repeat(_delete_domain, (domain,))
+        logging.info("domain %s removed", args.domainname)
+    except Exception:
+        logging.exception("domain can't be removed")
+
+    pool = repeat(conn.storagePoolLookupByName, ("images",))
+    for volume_name in repeat(pool.listVolumes, ()):
+        if not volume_name.startswith(args.domainname):
+            continue
+        try:
+            repeat(_delete_volume, (pool, volume_name,))
+            logging.info("volume %s removed", volume_name)
+        except Exception:
+            logging.exception("volume %s can not be removed", volume_name)
+
+if __name__ == "__main__":
+    _main()

roles/copr/backend/files/provision/libvirt-list

@@ -0,0 +1,52 @@
+#! /usr/bin/python3
+
+"""
+List all the Resalloc Pool-related LibVirt domains that are either (a) still
+defined/running, or (b) have some resource (e.g. storage) still available in the
+LibVirt hypervisor.
+"""
+
+import argparse
+import sys
+
+import libvirt
+
+def _get_parser():
+    parser = argparse.ArgumentParser()
+    parser.add_argument("--connection", required=True)
+    parser.add_argument("--pool", required=True)
+    return parser
+
+def _main():
+    args = _get_parser().parse_args()
+
+    try:
+        conn = libvirt.openReadOnly(args.connection)
+    except libvirt.libvirtError:
+        print('Failed to open connection to the hypervisor')
+        sys.exit(1)
+
+    # Gather the list of all domains here
+    vm_names = set()
+
+    # List all the volumes in the 'images' pool that seem to be related to given
+    # Pool name
+    pool = conn.storagePoolLookupByName("images")
+    for volume in pool.listVolumes():
+        if volume.startswith(args.pool):
+            vm_names.add(volume.rsplit("_", 1)[0])
+
+    # List all domains that are related to given Pool (just to be 100% sure, but
+    # this shouldn't add any new items to the vm_names set actually).
+    for domain in conn.listAllDomains():
+        name = domain.name()
+        if name.startswith(args.pool):
+            vm_names.add(name)
+
+    # Print them out, so upper level tooling can work with the list.  See:
+    # roles/copr/backend/files/provision/libvirt-list
+    for name in vm_names:
+        print(name)
+
+if __name__ == "__main__":
+    _main()

roles/copr/backend/templates/resalloc/vm-delete.j2

@@ -66,14 +66,4 @@ copr_p09_01*)
 esac
 
 # The rest of this script is LibVirt only!
-
-repeat()
-{
-    for _ in a b c; do
-        "$@" && break
-        sleep 15
-    done
-}
-
-repeat virsh -c "$conn" destroy  "$RESALLOC_NAME"
-repeat virsh -c "$conn" undefine "$RESALLOC_NAME" --remove-all-storage --nvram
+{{ provision_directory }}/libvirt-delete --connection "$conn" "$RESALLOC_NAME"