Cleanup exception logging in static provider

The static provider was logging a lot of exceptions with traceback in
case of an unreachable nodes.

Since offline nodes are part of the normal operation (e.g. for
maintenance) and we don't gain any additional insights from the
traceback, the log level was reduced to warning on StaticNodeErrors.

The warning messages will still log the exception message, so we don't
loose any important information. In case of other exceptions we will
still print the full traceback.

Change-Id: I5a6035a090acac2edb8529e91be63995feceb23d

nodepool/driver/static/provider.py

@@ -66,8 +66,7 @@ class StaticNodeProvider(Provider):
                                       gather_hostkeys=gather_hostkeys)
         except exceptions.ConnectionTimeoutException:
             raise StaticNodeError(
-                "%s:%s: ConnectionTimeoutException" % (
-                    node["name"], node["connection-port"]))
+                "{}: ConnectionTimeoutException".format(nodeTuple(node)))
 
         if not gather_hostkeys:
             return []
@@ -76,11 +75,11 @@ class StaticNodeProvider(Provider):
         if set(node["host-key"]).issubset(set(keys)):
             return keys
 
-        self.log.debug("%s: Registered key '%s' not in %s" % (
-            node["name"], node["host-key"], keys
-        ))
-        raise StaticNodeError("%s: host key mismatches (%s)" %
-                              (node["name"], keys))
+        node_tuple = nodeTuple(node)
+        self.log.debug("%s: Registered key '%s' not in %s",
+                       node_tuple, node["host-key"], keys)
+        raise StaticNodeError(
+            "{}: host key mismatches ({})".format(node_tuple, keys))
 
     def getRegisteredReadyNodes(self, node_tuple):
         '''
@@ -129,9 +128,10 @@ class StaticNodeProvider(Provider):
                                timeout=static_node["timeout"],
                                gather_hostkeys=False)
             return True
-        except Exception:
-            self.log.exception("Failed to connect to node %s:",
-                               static_node["name"])
+        except Exception as exc:
+            self.log.warning("Failed to connect to node %s: %s",
+                             node_tuple, exc)
+
         try:
             self.deregisterNode(count=1, node_tuple=node_tuple)
         except Exception:
@@ -319,14 +319,22 @@ class StaticNodeProvider(Provider):
             for node in pool.nodes:
                 try:
                     self.syncNodeCount(registered, node, pool)
+                except StaticNodeError as exc:
+                    self.log.warning("Couldn't sync node: %s", exc)
+                    continue
                 except Exception:
-                    self.log.exception("Couldn't sync node:")
+                    self.log.exception("Couldn't sync node %s:",
+                                       nodeTuple(node))
                     continue
 
                 try:
                     self.updateNodeFromConfig(node)
+                except StaticNodeError as exc:
+                    self.log.warning("Couldn't update static node: %s", exc)
+                    continue
                 except Exception:
-                    self.log.exception("Couldn't update static node:")
+                    self.log.exception("Couldn't update static node %s:",
+                                       nodeTuple(node))
                     continue
 
                 static_nodes[nodeTuple(node)] = node
@@ -386,11 +394,16 @@ class StaticNodeProvider(Provider):
                 for node in pool.nodes:
                     try:
                         self.syncNodeCount(registered, node, pool)
+                    except StaticNodeError as exc:
+                        self.log.warning("Couldn't sync node: %s", exc)
+                        continue
                     except Exception:
                         self.log.exception("Couldn't sync node:")
                         continue
                     try:
                         self.assignReadyNodes(node, pool)
+                    except StaticNodeError as exc:
+                        self.log.warning("Couldn't assign ready node: %s", exc)
                     except Exception:
                         self.log.exception("Couldn't assign ready nodes:")
 
@@ -419,7 +432,8 @@ class StaticNodeProvider(Provider):
         '''
         # It's possible a deleted node no longer exists in our config, so
         # don't bother to reregister.
-        static_node = self.poolNodes().get(nodeTuple(node))
+        node_tuple = nodeTuple(node)
+        static_node = self.poolNodes().get(node_tuple)
         if static_node is None:
             return
 
@@ -431,7 +445,7 @@ class StaticNodeProvider(Provider):
                     "Cannot get registered nodes for re-registration:"
                 )
                 return
-            current_count = registered[nodeTuple(node)]
+            current_count = registered[node_tuple]
 
             # It's possible we were not able to de-register nodes due to a
             # config change (because they were in use). In that case, don't
@@ -442,5 +456,8 @@ class StaticNodeProvider(Provider):
             try:
                 self.registerNodeFromConfig(
                     1, node.provider, node.pool, static_node)
+            except StaticNodeError as exc:
+                self.log.warning("Cannot re-register deleted node: %s", exc)
             except Exception:
-                self.log.exception("Cannot re-register deleted node %s", node)
+                self.log.exception("Cannot re-register deleted node %s:",
+                                   node_tuple)