backend: add resalloc ticket info to backend.log

And enhance the ticket info with the list of requested tags.

backend/copr_backend/background_worker_build.py

@@ -467,11 +467,11 @@ def _alloc_host(self):
         Set self.host with ready RemoteHost, and return True.  Keep re-trying
         upon allocation failure.  Return False if the request was canceled.
         """
-        self.log.info("Trying to allocate VM")
 
         vm_factory = ResallocHostFactory(server=self.opts.resalloc_connection)
         while True:
             self.host = vm_factory.get_host(self.job.tags, self.job.sandbox)
+            self.log.info("Trying to allocate VM: %s", self.host.info)
             self._proctitle("Waiting for VM, info: {}".format(self.host.info))
             success = CancellableThreadTask(
                 self.host.wait_ready,

backend/copr_backend/vm_alloc.py

@@ -88,9 +88,8 @@ class ResallocHost(RemoteHost):
     https://github.com/praiskup/resalloc
     """
     ticket = None
-
-    """ RESALLOC_NAME """
     name = None
+    requested_tags = None
 
     def parse_ticket_data(self):
         """
@@ -139,6 +138,8 @@ def info(self):
             message += ", hostname={}".format(self.hostname)
         if self.name:
             message += ", name={}".format(self.name)
+        if self.requested_tags:
+            message += f", requested_tags={self.requested_tags}"
         return message
 
 
@@ -168,4 +169,5 @@ def get_host(self, tags=None, sandbox=None):
 
         host = ResallocHost()
         host.ticket = self.conn.newTicket(request_tags, sandbox)
+        host.requested_tags = request_tags
         return host