more meaningful messages or logs for "The feature requested is not implemented"

[Nowaker]

After installing an agent on a new machine, it wasn't working for me. I was able to create a VM, but I was not able to list networks. I was able to define VM XML, but I was not able to create a new disk in Storage tab.

Four hours of debugging led me to find the reason: #1049.

Since this kind of problem always repeats for a lot of users we need a better error reporting for this.

If some modules don't load (like in #1049) we need a way of knowing it. Whenever Archipel Agent receives a stanza that no module wants to handle, ERROR (or at least WARN) should be logged:

ERROR: Got a stanza that no module can process. You are probably missing a module, module hasn't been installed correctly, or you haven't enabled it in archipel.conf.
INFO: Currently activated modules: a, b, c.
INFO: Currently installed modules: a, b, c, d, e, f.

xmpppy log:

Mar 30 23:49:30 asgard.pacmanvps.com runarchipel[2084]: DEBUG: socket       got   <iq from='admin@xmpp.pacmanvps.com/ArchipelController' to='asgard@xmpp.pacmanvps.com/asgard.pacmanvps.com' type='get' id='51124'>
Mar 30 23:49:30 asgard.pacmanvps.com runarchipel[2084]: <query xmlns='archipel:hypervisor:network'>
Mar 30 23:49:30 asgard.pacmanvps.com runarchipel[2084]: <archipel action='get'/>
Mar 30 23:49:30 asgard.pacmanvps.com runarchipel[2084]: </query>
Mar 30 23:49:30 asgard.pacmanvps.com runarchipel[2084]: </iq>
Mar 30 23:49:30 asgard.pacmanvps.com runarchipel[2084]: <iq from='admin@xmpp.pacmanvps.com/ArchipelController' to='asgard@xmpp.pacmanvps.com/asgard.pacmanvps.com' type='get' id='51125'>
Mar 30 23:49:30 asgard.pacmanvps.com runarchipel[2084]: <query xmlns='archipel:hypervisor:network'>
Mar 30 23:49:30 asgard.pacmanvps.com runarchipel[2084]: <archipel action='getnics'/>
Mar 30 23:49:30 asgard.pacmanvps.com runarchipel[2084]: </query>
Mar 30 23:49:30 asgard.pacmanvps.com runarchipel[2084]: </iq>
Mar 30 23:49:30 asgard.pacmanvps.com runarchipel[2084]: DEBUG: dispatcher   ok    Got jabber:client/iq stanza
Mar 30 23:49:30 asgard.pacmanvps.com runarchipel[2084]: DEBUG: dispatcher   ok    Dispatching iq stanza with type->get props->[u'archipel:hypervisor:network'] id->51124
Mar 30 23:49:30 asgard.pacmanvps.com runarchipel[2084]: DEBUG: socket       sent  <iq to="admin@xmpp.pacmanvps.com/ArchipelController" from="asgard@xmpp.pacmanvps.com/asgard.pacmanvps.com" id="51124" type="error">
Mar 30 23:49:30 asgard.pacmanvps.com runarchipel[2084]: <query xmlns="archipel:hypervisor:network">
Mar 30 23:49:30 asgard.pacmanvps.com runarchipel[2084]: <archipel action="get" />
Mar 30 23:49:30 asgard.pacmanvps.com runarchipel[2084]: </query>
Mar 30 23:49:30 asgard.pacmanvps.com runarchipel[2084]: <error code="501" type="cancel">
Mar 30 23:49:30 asgard.pacmanvps.com runarchipel[2084]: <feature-not-implemented xmlns="urn:ietf:params:xml:ns:xmpp-stanzas" />
Mar 30 23:49:30 asgard.pacmanvps.com runarchipel[2084]: <text xmlns="urn:ietf:params:xml:ns:xmpp-stanzas">The feature requested is not implemented by the recipient or server and therefore cannot be processed.</text>
Mar 30 23:49:30 asgard.pacmanvps.com runarchipel[2084]: </error>
Mar 30 23:49:30 asgard.pacmanvps.com runarchipel[2084]: </iq>
Mar 30 23:49:30 asgard.pacmanvps.com runarchipel[2084]: DEBUG: dispatcher   ok    Got jabber:client/iq stanza
Mar 30 23:49:30 asgard.pacmanvps.com runarchipel[2084]: DEBUG: dispatcher   ok    Dispatching iq stanza with type->get props->[u'archipel:hypervisor:network'] id->51125
Mar 30 23:49:30 asgard.pacmanvps.com runarchipel[2084]: DEBUG: socket       sent  <iq to="admin@xmpp.pacmanvps.com/ArchipelController" from="asgard@xmpp.pacmanvps.com/asgard.pacmanvps.com" id="51125" type="error">
Mar 30 23:49:30 asgard.pacmanvps.com runarchipel[2084]: <query xmlns="archipel:hypervisor:network">
Mar 30 23:49:30 asgard.pacmanvps.com runarchipel[2084]: <archipel action="getnics" />
Mar 30 23:49:30 asgard.pacmanvps.com runarchipel[2084]: </query>
Mar 30 23:49:30 asgard.pacmanvps.com runarchipel[2084]: <error code="501" type="cancel">
Mar 30 23:49:30 asgard.pacmanvps.com runarchipel[2084]: <feature-not-implemented xmlns="urn:ietf:params:xml:ns:xmpp-stanzas" />
Mar 30 23:49:30 asgard.pacmanvps.com runarchipel[2084]: <text xmlns="urn:ietf:params:xml:ns:xmpp-stanzas">The feature requested is not implemented by the recipient or server and therefore cannot be processed.</text>
Mar 30 23:49:30 asgard.pacmanvps.com runarchipel[2084]: </error>
Mar 30 23:49:30 asgard.pacmanvps.com runarchipel[2084]: </iq>