Have persistent ipmi command objects break selves on reconfig

When any reconfiguration happens, break a command object (and the session that lies beneath).
This does cause needless churn in response to some changes that wouldn't matter, but it's a
small price to pay for the simplicity of not bothering to be fancier.

TODO

@@ -29,7 +29,4 @@ KeyError: ''
 -confetty to do right thing with respect to status updates when run right on a
  console.  It currently clutters up the screen with data that would land in
  a titlebar
--audit log did not show confetty activity for starting console
--ipmi plugin needs to watch for connection attribute changes.  test case is to
- connect to a bmc and then misconfigure.  Currently, it keeps working, it should
- break.  watchattribs is the key
+-audit log did not show confetty activity for starting console

plugins/hardwaremanagement/ipmi.py

@@ -32,6 +32,17 @@ _ipmithread = None
 _ipmiwaiters = []
 
 
+class IpmiCommandWrapper(ipmicommand.Command):
+    def __init__(self, node, cfm, **kwargs):
+        self._attribwatcher = cfm.watch_attributes(
+            (node,),('secret.hardwaremanagementuser',
+                     'secret.hardwaremanagementpassphrase', 'secret.ipmikg',
+                     'hardwaremanagement.manager'), self._attribschanged)
+        super(self.__class__, self).__init__(**kwargs)
+
+    def _attribschanged(self, nodeattribs, configmanager, **kwargs):
+        self.ipmi_session._mark_broken()
+
 def _ipmi_evtloop():
     while True:
         try:
@@ -219,8 +230,9 @@ class IpmiHandler(object):
         if ((node, tenant) not in persistent_ipmicmds or
                 not persistent_ipmicmds[(node, tenant)].ipmi_session.logged):
             self._logevt = threading.Event()
-            persistent_ipmicmds[(node, tenant)] = ipmicommand.Command(
-                bmc=connparams['bmc'], userid=connparams['username'],
+            persistent_ipmicmds[(node, tenant)] = IpmiCommandWrapper(
+                node, cfg, bmc=connparams['bmc'],
+                userid=connparams['username'],
                 password=connparams['passphrase'], kg=connparams['kg'],
                 port=connparams['port'], onlogon=self.logged)
         self.ipmicmd = persistent_ipmicmds[(node, tenant)]