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kvm: Aqcuire lock when running security group Python script #1408

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Merged
merged 1 commit into from
May 4, 2016
Merged

kvm: Aqcuire lock when running security group Python script #1408

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28 changes: 27 additions & 1 deletion scripts/vm/network/security_group.py
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Original file line number Diff line number Diff line change
Expand Up @@ -26,8 +26,11 @@
from optparse import OptionParser, OptionGroup, OptParseError, BadOptionError, OptionError, OptionConflictError, OptionValueError
import re
import libvirt
import fcntl
import time

logpath = "/var/run/cloud/" # FIXME: Logs should reside in /var/log/cloud
lock_file = "/var/lock/cloudstack_security_group.lock"
iptables = Command("iptables")
bash = Command("/bin/bash")
ebtables = Command("ebtables")
Expand All @@ -36,6 +39,21 @@
hyper = cfo.getEntry("hypervisor.type")
if hyper == "lxc":
driver = "lxc:///"

lock_handle = None

def obtain_file_lock(path):
global lock_handle

try:
lock_handle = open(path, 'w')
fcntl.flock(lock_handle, fcntl.LOCK_EX | fcntl.LOCK_NB)
return True
except IOError:
pass

return False

def execute(cmd):
logging.debug(cmd)
return bash("-c", cmd).stdout
Expand Down Expand Up @@ -303,7 +321,7 @@ def default_network_rules_systemvm(vm_name, localbrname):
for bridge in bridges:
if bridge != localbrname:
if not addFWFramework(bridge):
return False
return False
brfw = getBrfw(bridge)
vifs = getVifsForBridge(vm_name, bridge)
for vif in vifs:
Expand Down Expand Up @@ -1029,6 +1047,14 @@ def addFWFramework(brname):
sys.exit(1)
cmd = args[0]
logging.debug("Executing command: " + str(cmd))

for i in range(0, 30):
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@rohityadavcloud rohityadavcloud Apr 26, 2016

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this can be refactored separately as an acquire lock method that may optionally accept a timeout

if obtain_file_lock(lock_file) is False:
logging.warn("Lock on %s is being held by other process. Waiting for release." % lock_file)
time.sleep(0.5)
else:
break

if cmd == "can_bridge_firewall":
can_bridge_firewall(args[1])
elif cmd == "default_network_rules":
Expand Down