@staticmethod
def getConnection(sliver_type):
- # TODO: error checking
- # vtype is of the form sliver.[LXC/QEMU] we need to lower case to lxc/qemu
+ """
+ returns a connection to the underlying libvirt service
+ a single connection is created and shared among slivers
+ this call ensures the connection is alive
+ and will reconnect if it appears to be necessary
+ """
+ # sliver_type comes from rec['type'] and is of the form sliver.{LXC,QEMU}
+ # so we need to lower case to lxc/qemu
vtype = sliver_type.split('.')[1].lower()
- uri = vtype + '://'
- return connections.setdefault(uri, libvirt.open(uri))
+ uri = vtype + ':///'
+ if uri not in connections:
+ # create connection
+ conn = libvirt.open(uri)
+ connections[uri] = conn
+ return conn
+ else:
+ # connection already available : check for health
+ conn = connections[uri]
+ # see if a reconnection is needed
+ try:
+ numDomains = conn.numOfDomains()
+ except:
+ logger.log("libvirt connection to {} looks broken - reconnecting".format(uri))
+ conn = libvirt.open(uri)
+ # if this fails then an expection is thrown outside of this function
+ numDomains = conn.numOfDomains()
+ return conn
def __init__(self, rec):
self.name = rec['name']