XenServer Software Development Kit Guide 4.1.0

Using the API

import sys, time

import XenAPI

Next the commandline arguments containing a server URL, username, password and a number of iterations

are parsed. The username and password are used to establish a session which is passed to the function

main, which is called multiple times in a loop. Note the use of try: finally: to make sure the program

logs out of its session at the end.

if __name__ == "__main__":

if len(sys.argv) <> 5:

print "Usage:"

print sys.argv[0], " <url> <username> <password> <iterations>"

sys.exit(1)

url = sys.argv[1]

username = sys.argv[2]

password = sys.argv[3]

iterations = int(sys.argv[4])

# First acquire a valid session by logging in:

session = XenAPI.Session(url)

session.xenapi.login_with_password(username, password)

try:

for i in range(iterations):

main(session, i)

finally:

session.xenapi.session.logout()

The main function examines each running VM in the system, taking care to filter out control domains (which

are part of the system and not controllable by the user). A list of running VMs and their current hosts is

constructed.

def main(session, iteration):

# Find a non-template VM object

all = session.xenapi.VM.get_all()

vms = []

hosts = []

for vm in all:

record = session.xenapi.VM.get_record(vm)

if not(record["is_a_template"]) and \

not(record["is_control_domain"]) and \

record["power_state"] == "Running":

vms.append(vm)

hosts.append(record["resident_on"])

print "%d: Found %d suitable running VMs" % (iteration, len(vms))

Next the list of hosts is rotated: