launcher: add pool quota debug and log information

This change logs the current pool quota as DEBUG and adds a
INFO log when a pool doesn't have enough quota to satisfy a request.

Change-Id: I78445f21f251d206d4fb0dce817a992685c8b319

nodepool/driver/__init__.py

@@ -446,10 +446,13 @@ class NodeRequestHandler(NodeRequestHandlerNotifications,
                 # If we calculate that we're at capacity, pause until nodes
                 # are released by Zuul and removed by the DeletedNodeWorker.
                 if not self.hasRemainingQuota(ntype):
+                    self.log.info(
+                        "Not enough quota remaining to satisfy request %s",
+                        self.request.id)
                     if not self.paused:
                         self.log.debug(
                             "Pausing request handling to satisfy request %s",
-                            self.request)
+                            self.request.id)
                     self.paused = True
                     self.zk.deleteOldestUnusedNode(self.provider.name,
                                                    self.pool.name)

nodepool/driver/openstack/handler.py

@@ -306,6 +306,7 @@ class OpenStackNodeRequestHandler(NodeRequestHandler):
                                       default=math.inf)
         pool_quota.subtract(
             self.manager.estimatedNodepoolQuotaUsed(self.zk, self.pool))
+        self.log.debug("Current pool quota: %s" % pool_quota)
         pool_quota.subtract(needed_quota)
         self.log.debug("Predicted remaining pool quota: %s", pool_quota)