Add JSON output and re-factor

Add a JSON output flag to enable this tool to more easily be called by
other scripts and used in pipelines. Re-factor a bit, add a class and
remove some code duplication

Change-Id: If4586cf18a7e30580a00e6d9d1d7e166d4001aea
This commit is contained in:
Matt Jarvis 2016-06-28 15:44:32 +01:00
parent e3b5bc9634
commit 651cd91f8e
1 changed files with 114 additions and 66 deletions

View File

@ -1,10 +1,11 @@
#!/usr/bin/env python
# pylint: disable=import-error
""" Utility to check validity of anti-affinity rules """
import os
import sys
import argparse
from collections import defaultdict, Counter
import json
from collections import Counter
from keystoneclient import session
from keystoneclient.auth.identity import v2
from keystoneclient.v2_0 import client as ksclient
@ -20,78 +21,125 @@ def get_credentials():
keystone_credentials['tenant_name'] = os.environ['OS_TENANT_NAME']
return keystone_credentials
def get_args():
""" Get commandline arguments """
parser = argparse.ArgumentParser(description='Nova Server Group anti-affinity rule checker')
parser.add_argument('--check', type=str, help='Validate the specified Server Group')
parser.add_argument('--list', type=str, help='List instances and their hypervisors for a given Server Group')
return parser.parse_args()
class NovaConnect(object):
"""
Base Nova connection class
"""
def __init__(self, args):
def get_server(serverid):
""" Return Server object """
return nova.servers.get(serverid)
credentials = get_credentials()
ksclient.Client(**credentials)
auth = v2.Password(**credentials)
sess = session.Session(auth=auth)
self.nova = nclient.Client(2, session=sess)
self.json = args.json
def get_group_members(server_group_id):
""" Return list of instance UUIDs present in a Server Group """
server_group = nova.server_groups.get(server_group_id)
if 'anti-affinity' in server_group.policies:
return server_group.members
else:
return False
def get_server(self, serverid):
"""
Return Server object
"""
return self.nova.servers.get(serverid)
def get_group_members(self, server_group_id):
"""
Return list of instance UUIDs present in a Server Group
"""
server_group = self.nova.server_groups.get(server_group_id)
if 'anti-affinity' in server_group.policies:
return server_group.members
else:
return False
def get_hypervisors(self, uid_list):
"""
Return a dict with hypervisors and names given a list of server uids
"""
ret = []
for uid in uid_list:
instance = self.get_server(uid)
hypervisor = getattr(instance, 'OS-EXT-SRV-ATTR:hypervisor_hostname'.split('.')[0])
ret.append({'id':uid, 'name':instance.name, 'hypervisor':hypervisor})
return ret
def print_group_members(self, server_group_id):
"""
Output detail on Server Group instances and their hypervisors
"""
group_members = self.get_group_members(server_group_id)
if group_members:
output = self.get_hypervisors(group_members)
if self.json:
print json.dumps(output)
else:
table = create_table(['Instance ID', 'Instance Name', 'Hypervisor'])
for instance in output:
table.add_row([instance['id'], instance['name'], instance['hypervisor']])
print table
else:
print "Server Group", server_group_id,\
"empty or does not have an anti-affinity policy set."
def print_group_duplicates(self, server_group_id):
"""
Evaluate whether any instances in a SG
have been scheduled to the same hypervisor
"""
group_members = self.get_group_members(server_group_id)
if group_members:
hypervisors = []
instances = self.get_hypervisors(group_members)
for instance in instances:
hypervisors.append(instance['hypervisor'])
dupes = [k for k, v in Counter(hypervisors).items() if v > 1]
if dupes:
instance_dupes = [instance for instance in instances
if instance['hypervisor'] in dupes]
if self.json:
print json.dumps(instance_dupes)
else:
print "Anti-affinity rules violated in Server Group:",\
server_group_id
table = create_table(['Instance ID', 'Instance Name', 'Hypervisor'])
for instance in instance_dupes:
table.add_row([instance['id'], instance['name'], instance['hypervisor']])
print table
else:
if not self.json:
print "No anti-affinity rules violated for Server Group:", server_group_id
else:
if not self.json:
print "Server Group", server_group_id,\
"empty or does not have an anti-affinity policy set."
def create_table(fields):
""" Boilerplate for PrettyTable """
"""
Boilerplate for PrettyTable
"""
table = prettytable.PrettyTable(fields, caching=False)
table.align = 'l'
return table
def print_group_members(server_group_id):
""" Print a table detailing Server Group instances and their hypervisors """
group_members = get_group_members(server_group_id)
if group_members:
table = create_table(['Instance ID', 'Instance', 'Hypervisor'])
for server in get_group_members(server_group_id):
instance = get_server(server)
hypervisor = getattr(instance, 'OS-EXT-SRV-ATTR:hypervisor_hostname'.split('.')[0])
table.add_row([instance.id, instance.name, hypervisor])
print table
else:
print "Server Group", server_group_id, "empty or does not have an anti-affinity policy set."
def get_args():
"""
Get commandline arguments
"""
parser = argparse.ArgumentParser(description='Nova Server Group anti-affinity rule checker')
parser.add_argument('--check', type=str, help='Validate the specified Server Group')
parser.add_argument('--list', type=str,
help='List instances and their hypervisors for a given Server Group')
parser.add_argument('--json', action='store_true', help='Output JSON')
return parser.parse_args()
def print_group_duplicates(server_group_id):
""" Evaluate whether any instances in a SG have been scheduled to the same hypervisor """
group_members = get_group_members(server_group_id)
if group_members:
hypervisors = []
instances = defaultdict(list)
for instance in get_group_members(server_group_id):
i = get_server(instance)
hypervisor = getattr(i, 'OS-EXT-SRV-ATTR:hypervisor_hostname')
instances[instance].append(i.name)
instances[instance].append(hypervisor)
hypervisors.append(hypervisor)
dupes = [k for k, v in Counter(hypervisors).items() if v > 1]
if dupes:
print "Anti-affinity rules violated in Server Group:", server_group_id
table = create_table(['Instance ID', 'Instance', 'Hypervisor'])
[table.add_row([instance_id, instance_name, hypervisor])
for instance_id, [instance_name, hypervisor] in instances.items()
if hypervisor in dupes]
print table
else:
print "No anti-affinity rules violated for Server Group:", server_group_id
else:
print "Server Group", server_group_id, "empty or does not have an anti-affinity policy set."
def main():
"""
Main script
"""
args = get_args()
nova_connect = NovaConnect(args)
if args.check:
nova_connect.print_group_duplicates(args.check)
if args.list:
nova_connect.print_group_members(args.list)
if __name__ == '__main__':
credentials = get_credentials()
keystone = ksclient.Client(**credentials)
auth = v2.Password(**credentials)
sess = session.Session(auth=auth)
nova = nclient.Client(2, session=sess)
args = get_args()
group = sys.argv[2]
if args.check:
print_group_duplicates(group)
if args.list:
print_group_members(group)
main()