test for existence of the newly config variables for backward compati…

…bility.

jobQueue.py

@@ -212,7 +212,10 @@ def getNextPendingJobReuse(self, target_id=None):
             # the limit for pool is not reached yet
             if self.preallocator.freePoolSize(job.vm.name) == 0 and \
                 self.preallocator.poolSize(job.vm.name) < Config.POOL_SIZE:
-                self.preallocator.incrementPoolSize(job.vm, Config.POOL_ALLOC_INCREMENT)
+                increment = 1
+                if hasattr(Config, 'POOL_ALLOC_INCREMENT') and Config.POOL_ALLOC_INCREMENT:
+                    increment = Config.POOL_ALLOC_INCREMENT
+                self.preallocator.incrementPoolSize(job.vm, increment)
 
             # If the job hasn't been assigned to a worker yet, see if there
             # is a free VM

preallocator.py

@@ -47,7 +47,8 @@ def decrementPoolSize(self, vm):
         Called by worker to shrink the pool, after returning a vm to free pool
         """
 
-        if not (Config.POOL_SIZE_LOW_WATER_MARK and vm.name in self.machines.keys()):
+        if not (hasattr(Config, 'POOL_SIZE_LOW_WATER_MARK') and
+                Config.POOL_SIZE_LOW_WATER_MARK and vm.name in self.machines.keys()):
             return
 
         delta = self.freePoolSize(vm.name) - Config.POOL_SIZE_LOW_WATER_MARK
@@ -61,9 +62,6 @@ def incrementPoolSize(self, vm, delta):
         Called by jobQueue to create the pool and allcoate given number of vms
         """
 
-        if not delta:  # POOL_ALLOC_INCREMENT may not be defined in Config
-            delta = 1
-
         self.lock.acquire()
         if vm.name not in self.machines.keys():
             self.machines.set(vm.name, [[], TangoQueue(vm.name)])

vmms/ec2SSH.py

@@ -151,12 +151,14 @@ def __init__(self, accessKeyId=None, accessKey=None):
         # When an instance is terminated, it's detached.
         self.asg = None
         self.auto_scaling_group = None
-        if config.Config.EC2_AUTO_SCALING_GROUP_NAME:
+        self.auto_scaling_group_name = None
+        if hasattr(config.Config, 'EC2_AUTO_SCALING_GROUP_NAME') and config.Config.EC2_AUTO_SCALING_GROUP_NAME:
             self.asg = boto3.client("autoscaling", config.Config.EC2_REGION)
             groups = self.asg.describe_auto_scaling_groups(AutoScalingGroupNames=[config.Config.EC2_AUTO_SCALING_GROUP_NAME])
             if len(groups['AutoScalingGroups']) == 1:
                 self.auto_scaling_group = groups['AutoScalingGroups'][0]
-                self.log.info("Use aws auto scaling group %s" % config.Config.EC2_AUTO_SCALING_GROUP_NAME)
+                self.auto_scaling_group_name = config.Config.EC2_AUTO_SCALING_GROUP_NAME
+                self.log.info("Use aws auto scaling group %s" % self.auto_scaling_group_name)
 
                 instances = self.asg.describe_auto_scaling_instances()['AutoScalingInstances']
             else:
@@ -323,7 +325,7 @@ def initializeVM(self, vm):
 
             if self.auto_scaling_group:
                 self.asg.attach_instances(InstanceIds=[newInstance.id],
-                                          AutoScalingGroupName=config.Config.EC2_AUTO_SCALING_GROUP_NAME)
+                                          AutoScalingGroupName=self.auto_scaling_group_name)
                 self.log.info("attach new instance %s to auto scaling group" % newInstance.id)
 
             # Save domain and id ssigned by EC2 in vm object
@@ -507,7 +509,7 @@ def destroyVM(self, vm):
                                                                 MaxRecords=1)
             if len(response['AutoScalingInstances']) == 1:
                 self.asg.detach_instances(InstanceIds=[vm.ec2_id],
-                                          AutoScalingGroupName=config.Config.EC2_AUTO_SCALING_GROUP_NAME,
+                                          AutoScalingGroupName=self.auto_scaling_group_name,
                                           ShouldDecrementDesiredCapacity=True)
                 self.log.info("detach instance %s %s from auto scaling group" % (vm.ec2_id, vm.name))
             else: