Пример #1
0
class BotoBalanceInterface(BalanceInterface):
    conn = None
    saveclcdata = False

    def __init__(self, clc_host, access_id, secret_key, token):
        #boto.set_stream_logger('foo')
        path='/services/elb'
        port=8773
        if clc_host[len(clc_host)-13:] == 'amazonaws.com':
            clc_host = clc_host.replace('ec2', 'elasticloadbalancing', 1)
            path = '/'
            reg = None
            port=443
        reg = RegionInfo(name='eucalyptus', endpoint=clc_host)
        self.conn = ELBConnection(access_id, secret_key, region=reg,
                                  port=port, path=path,
                                  is_secure=True, security_token=token, debug=0)
        self.conn.https_validate_certificates = False
        self.conn.http_connection_kwargs['timeout'] = 30

    def __save_json__(self, obj, name):
        f = open(name, 'w')
        json.dump(obj, f, cls=BotoJsonBalanceEncoder, indent=2)
        f.close()

    def create_load_balancer(self, name, zones, listeners, subnets=None,
                             security_groups=None, scheme='internet-facing'):
        return self.conn.create_load_balancer(name, zones, listeners, subnets, security_groups, scheme)
    
    def delete_load_balancer(self, name):
        return self.conn.delete_load_balancer(name)

    def get_all_load_balancers(self, load_balancer_names=None):
        return []
        obj = self.conn.get_all_load_balancers(load_balancer_names)
        if self.saveclcdata:
            self.__save_json__(obj, "mockdata/ELB_Balancers.json")
        return obj

    def deregister_instances(self, load_balancer_name, instances):
        return self.conn.deregister_instances(load_balancer_name, instances)

    def register_instances(self, load_balancer_name, instances):
        return self.conn.register_instances(load_balancer_name, instances)

    def create_load_balancer_listeners(self, name, listeners):
        return self.conn.create_load_balancer_listeners(name, listeners)

    def delete_load_balancer_listeners(self, name, ports):
        return self.conn.delete_load_balancer_listeners(name, ports)

    def configure_health_check(self, name, health_check):
        return self.conn.configure_health_check(name, health_check)

    def describe_instance_health(self, load_balancer_name, instances=None):
        obj = self.conn.describe_instance_health(load_balancer_name, instances)
        if self.saveclcdata:
            self.__save_json__(obj, "mockdata/ELB_Instances.json")
        return obj
class BotoBalanceInterface(BalanceInterface):
    conn = None
    saveclcdata = False

    def __init__(self, clc_host, access_id, secret_key, token):
        self.access_id = access_id
        self.secret_key = secret_key
        self.token = token
        self.set_endpoint(clc_host)

    def set_endpoint(self, endpoint):
        #boto.set_stream_logger('foo')
        reg = RegionInfo(name='eucalyptus', endpoint=endpoint)
        path = '/services/LoadBalancing'
        port = 8773
        if endpoint[len(endpoint)-13:] == 'amazonaws.com':
            endpoint = endpoint.replace('ec2', 'elasticloadbalancing', 1)
            path = '/'
            reg = RegionInfo(endpoint=endpoint)
            port = 443
        self.conn = ELBConnection(self.access_id, self.secret_key, region=reg,
                                  port=port, path=path,
                                  is_secure=True, security_token=self.token, debug=0)
        self.conn.https_validate_certificates = False
        self.conn.http_connection_kwargs['timeout'] = 30

    def __save_json__(self, obj, name):
        f = open(name, 'w')
        json.dump(obj, f, cls=BotoJsonBalanceEncoder, indent=2)
        f.close()

    def create_load_balancer(self, name, zones, listeners, subnets=None,
                             security_groups=None, scheme='internet-facing'):
        return self.conn.create_load_balancer(name, zones, listeners, subnets, security_groups, scheme)

    def delete_load_balancer(self, name):
        return self.conn.delete_load_balancer(name)

    def get_all_load_balancers(self, load_balancer_names=None):
        params = {}
        if load_balancer_names:
            self.build_list_params(params, load_balancer_names,
                                   'LoadBalancerNames.member.%d')
        http_request = self.conn.build_base_http_request('GET', '/', None,
                                                         params, {}, '',
                                                         self.conn.server_name())
        http_request.params['Action'] = 'DescribeLoadBalancers'
        http_request.params['Version'] = self.conn.APIVersion
        response = self.conn._mexe(http_request, override_num_retries=2)
        body = response.read()
        boto.log.debug(body)
        if not body:
            boto.log.error('Null body %s' % body)
            raise self.conn.ResponseError(response.status, response.reason, body)
        elif response.status == 200:
            obj = boto.resultset.ResultSet([('member', boto.ec2.elb.loadbalancer.LoadBalancer)])
            h = boto.handler.XmlHandler(obj, self.conn)
            import xml.sax;

            xml.sax.parseString(body, h)
            if self.saveclcdata:
                self.__save_json__(obj, "mockdata/ELB_Balancers.json")
            return obj
        else:
            boto.log.error('%s %s' % (response.status, response.reason))
            boto.log.error('%s' % body)
            raise self.conn.ResponseError(response.status, response.reason, body)


    def deregister_instances(self, load_balancer_name, instances):
        return self.conn.deregister_instances(load_balancer_name, instances)

    def register_instances(self, load_balancer_name, instances):
        return self.conn.register_instances(load_balancer_name, instances)

    def create_load_balancer_listeners(self, name, listeners):
        return self.conn.create_load_balancer_listeners(name, listeners)

    def delete_load_balancer_listeners(self, name, ports):
        return self.conn.delete_load_balancer_listeners(name, ports)

    def configure_health_check(self, name, health_check):
        return self.conn.configure_health_check(name, health_check)

    def describe_instance_health(self, load_balancer_name, instances=None):
        obj = self.conn.describe_instance_health(load_balancer_name, instances)
        if self.saveclcdata:
            self.__save_json__(obj, "mockdata/ELB_Instances.json")
        return obj
Пример #3
0
class AutoScale:
    def __init__(self, args):
        """
        Initializing basic variables needed for auto scaling
        """
        self.configs = ConfigParser.RawConfigParser()
        self.args = args
        self.test_props = {}
        self.props = {}
        self.ec2_connection = EC2Connection(self.args.access_key,
                                            self.args.secret_key)
        self.autoscale_connection = AutoScaleConnection(
            self.args.access_key, self.args.secret_key)
        self.elb_connection = ELBConnection(self.args.access_key,
                                            self.args.secret_key)
        self.cw_connection = CloudWatchConnection(self.args.access_key,
                                                  self.args.secret_key)
        self.firstInstance = None
        self.launchConfiguration = None
        self.healthCheck = None

    def loadConfigs(self):
        """
        FIX ME: Currently doesnt do anything
        This method will load the configurations from boto config file if present else will 
        accept parameters passed by user.
        """
        if os.path.isfile("/etc/boto.cfg"):
            self.configs.read("/etc/boto.cfg")
            conf = self.configs.sections()
            self.populateConfigs(conf)
        if os.path.isfile("~/.boto"):
            self.configs.read("~/.boto")
            conf = self.configs.sections()
            self.populateConfigs(conf)

        print ">>> Loaded configs"

    def populateConfigs(self, sections):
        for section in sections:
            self.boto_props[section] = self.configs.items(section)
            for item in self.boto_props[section]:
                key, value = item
                if not self.props.has_key(key):
                    self.props[key] = value

    def createLaunchConfiguration(self, lc_name, ami_id, key_name):
        """
        Creates launch configuration for the auto scaling cluster
        """
        self.launchConfiguration = LaunchConfiguration(name=lc_name,
                                                       image_id=ami_id,
                                                       key_name=key_name)
        self.autoscale_connection.create_launch_configuration(
            self.launchConfiguration)
        print ">>> Created launch configuration: " + lc_name

    def createAutoScaleGroup(self, asg_name):
        """
        Create a Auto scaling group for the auto scaling cluster
        """
        autoScalingGroup = AutoScalingGroup(
            group_name=asg_name,
            load_balancers=[self.args.lb_name],
            launch_config=self.launchConfiguration,
            min_size=self.args.min_size,
            max_size=self.args.max_size,
            availability_zones=['us-east-1a'])
        self.autoscale_connection.create_auto_scaling_group(autoScalingGroup)
        print ">>> Created auto scaling group: " + asg_name

    def createTrigger(self, trigger_name, measure, asg_name):
        """
        Trigger to spawn new instances as per specific metrics
        """
        alarm_actions = []
        dimensions = {"AutoScalingGroupName": asg_name}
        policies = self.autoscale_connection.get_all_policies(
            as_group=self.args.asg_name, policy_names=[self.args.asp_name])
        for policy in policies:
            alarm_actions.append(policy.policy_arn)
        alarm = MetricAlarm(name=trigger_name,
                            namespace="AWS/EC2",
                            metric=measure,
                            statistic="Average",
                            comparison=">=",
                            threshold=50,
                            period=60,
                            unit="Percent",
                            evaluation_periods=2,
                            alarm_actions=alarm_actions,
                            dimensions=dimensions)

        self.cw_connection.create_alarm(alarm)
        print ">>> Created trigger: " + self.args.trigger

    def createAutoScalePolicy(self, asp_name):
        """
        Creates a Auto scaling policy to Add/Remove a instance from auto scaling cluster
        """
        self.autoScalingUpPolicy = ScalingPolicy(
            name=asp_name + '-up',
            adjustment_type="ChangeInCapacity",
            as_name=self.args.asg_name,
            scaling_adjustment=1,
            cooldown=180)
        self.autoScalingDownPolicy = ScalingPolicy(
            name=asp_name + '-down',
            adjustment_type="ChangeInCapacity",
            as_name=self.args.asg_name,
            scaling_adjustment=-1,
            cooldown=180)

        self.autoscale_connection.create_scaling_policy(
            self.autoScalingUpPolicy)
        self.autoscale_connection.create_scaling_policy(
            self.autoScalingDownPolicy)

        print ">>> Created auto scaling policy: " + asp_name

    def configureHealthCheck(self, target):
        """
        Configures health check for the cluster
        """
        self.healthCheck = HealthCheck(target=target, timeout=5)
        print ">>> Configured health check for: " + target

    def createLoadBalancer(self, lb_name, region, lb_port, instance_port,
                           protocol):
        """
        Creates a load balancer for cluster
        """
        listener = (int(lb_port), int(instance_port), protocol)
        tuple_list = []
        tuple_list.append(listener)
        lbs = self.elb_connection.get_all_load_balancers()
        for lb in lbs:
            if lb.name != lb_name:
                self.elb_connection.create_load_balancer(
                    lb_name, [region], tuple_list)
                self.elb_connection.configure_health_check(
                    name=lb_name, health_check=self.healthCheck)
                print ">>> Created load balancer: " + lb_name
            else:
                print "Load balancer with name '" + lb_name + "' already exists"

    def startInstance(self, image_id, key_name, region, instance_type):
        """
        Starts the first instance which will be serving requests irrespective of auto scaling 
        instances.
        """
        reservation = self.ec2_connection.run_instances(
            image_id=image_id,
            min_count=1,
            max_count=1,
            placement=region,
            key_name=key_name,
            instance_type=instance_type)
        #        for instance in reservation.instances:
        #            instance.add_tag('node', '0')
        #            break

        self.firstInstance = reservation.instances[0].id.split('\'')[0]
        print ">>> Started instance: ", self.firstInstance

    def registerInstanceToELB(self, lb_name):
        """
        Register the first instance started to the Elastic Load Balancer.
        """
        self.elb_connection.register_instances(load_balancer_name=lb_name,
                                               instances=[self.firstInstance])
        print ">>> Registered instance '", self.firstInstance, "' to load balancer '" + lb_name + "'"

    def setUp(self):
        """
        Set's up the auto scaling for the application
        """
        # STEP 1: Load the configurations
        self.loadConfigs()
        # STEP 2: Configure the health check for the instances
        self.configureHealthCheck(self.args.lb_target)
        # STEP 3: Create a load balancer
        self.createLoadBalancer(self.args.lb_name, self.args.region,
                                self.args.lb_port, self.args.instance_port,
                                self.args.protocol)
        # STEP 4: Start the first instance
        self.startInstance(self.args.ami_id, self.args.key_name,
                           self.args.region, self.args.instance_type)
        # STEP 5: Register the instance to the load balancer created in STEP 4
        self.registerInstanceToELB(self.args.lb_name)
        # STEP 6: Create launch configuration to launch instances by auto scale
        self.createLaunchConfiguration(self.args.lc_name, self.args.ami_id,
                                       self.args.key_name)
        # STEP 7: Create a auto scale group which will manage the instances started by auto scaling
        self.createAutoScaleGroup(self.args.asg_name)
        # STEP 8: Create a auto scaling policy to say add/remove a node
        self.createAutoScalePolicy(self.args.asp_name)
        # STEP 9: Create a trigger, so that auto scaling can trigger it to start
        # or remove a instance from auto scaling group
        self.createTrigger(self.args.trigger, self.args.measure,
                           self.args.asg_name)
Пример #4
0
class BotoBalanceInterface(BalanceInterface):
    conn = None
    saveclcdata = False

    def __init__(self, clc_host, access_id, secret_key, token):
        #boto.set_stream_logger('foo')
        path = '/services/LoadBalancing'
        port = 8773
        if clc_host[len(clc_host) - 13:] == 'amazonaws.com':
            clc_host = clc_host.replace('ec2', 'elasticloadbalancing', 1)
            path = '/'
            reg = None
            port = 443
        reg = RegionInfo(name='eucalyptus', endpoint=clc_host)
        self.conn = ELBConnection(access_id,
                                  secret_key,
                                  region=reg,
                                  port=port,
                                  path=path,
                                  is_secure=True,
                                  security_token=token,
                                  debug=0)
        self.conn.https_validate_certificates = False
        self.conn.http_connection_kwargs['timeout'] = 30

    def __save_json__(self, obj, name):
        f = open(name, 'w')
        json.dump(obj, f, cls=BotoJsonBalanceEncoder, indent=2)
        f.close()

    def create_load_balancer(self,
                             name,
                             zones,
                             listeners,
                             subnets=None,
                             security_groups=None,
                             scheme='internet-facing'):
        return self.conn.create_load_balancer(name, zones, listeners, subnets,
                                              security_groups, scheme)

    def delete_load_balancer(self, name):
        return self.conn.delete_load_balancer(name)

    def get_all_load_balancers(self, load_balancer_names=None):
        obj = self.conn.get_all_load_balancers(load_balancer_names)
        if self.saveclcdata:
            self.__save_json__(obj, "mockdata/ELB_Balancers.json")
        return obj

    def deregister_instances(self, load_balancer_name, instances):
        return self.conn.deregister_instances(load_balancer_name, instances)

    def register_instances(self, load_balancer_name, instances):
        return self.conn.register_instances(load_balancer_name, instances)

    def create_load_balancer_listeners(self, name, listeners):
        return self.conn.create_load_balancer_listeners(name, listeners)

    def delete_load_balancer_listeners(self, name, ports):
        return self.conn.delete_load_balancer_listeners(name, ports)

    def configure_health_check(self, name, health_check):
        return self.conn.configure_health_check(name, health_check)

    def describe_instance_health(self, load_balancer_name, instances=None):
        obj = self.conn.describe_instance_health(load_balancer_name, instances)
        if self.saveclcdata:
            self.__save_json__(obj, "mockdata/ELB_Instances.json")
        return obj
class BotoBalanceInterface(BalanceInterface):
    conn = None
    saveclcdata = False

    def __init__(self, clc_host, access_id, secret_key, token):
        #boto.set_stream_logger('foo')
        path = '/services/LoadBalancing'
        port = 8773
        if clc_host[len(clc_host) - 13:] == 'amazonaws.com':
            clc_host = clc_host.replace('ec2', 'elasticloadbalancing', 1)
            path = '/'
            reg = None
            port = 443
        reg = RegionInfo(name='eucalyptus', endpoint=clc_host)
        self.conn = ELBConnection(access_id,
                                  secret_key,
                                  region=reg,
                                  port=port,
                                  path=path,
                                  is_secure=True,
                                  security_token=token,
                                  debug=0)
        self.conn.https_validate_certificates = False
        self.conn.http_connection_kwargs['timeout'] = 30

    def __save_json__(self, obj, name):
        f = open(name, 'w')
        json.dump(obj, f, cls=BotoJsonBalanceEncoder, indent=2)
        f.close()

    def create_load_balancer(self,
                             name,
                             zones,
                             listeners,
                             subnets=None,
                             security_groups=None,
                             scheme='internet-facing'):
        return self.conn.create_load_balancer(name, zones, listeners, subnets,
                                              security_groups, scheme)

    def delete_load_balancer(self, name):
        return self.conn.delete_load_balancer(name)

    def get_all_load_balancers(self, load_balancer_names=None):
        params = {}
        if load_balancer_names:
            self.build_list_params(params, load_balancer_names,
                                   'LoadBalancerNames.member.%d')
        http_request = self.conn.build_base_http_request(
            'GET', '/', None, params, {}, '', self.conn.server_name())
        http_request.params['Action'] = 'DescribeLoadBalancers'
        http_request.params['Version'] = self.conn.APIVersion
        response = self.conn._mexe(http_request, override_num_retries=2)
        body = response.read()
        boto.log.debug(body)
        if not body:
            boto.log.error('Null body %s' % body)
            raise self.conn.ResponseError(response.status, response.reason,
                                          body)
        elif response.status == 200:
            obj = boto.resultset.ResultSet([
                ('member', boto.ec2.elb.loadbalancer.LoadBalancer)
            ])
            h = boto.handler.XmlHandler(obj, self.conn)
            import xml.sax
            xml.sax.parseString(body, h)
            if self.saveclcdata:
                self.__save_json__(obj, "mockdata/ELB_Balancers.json")
            return obj
        else:
            boto.log.error('%s %s' % (response.status, response.reason))
            boto.log.error('%s' % body)
            raise self.conn.ResponseError(response.status, response.reason,
                                          body)

    def deregister_instances(self, load_balancer_name, instances):
        return self.conn.deregister_instances(load_balancer_name, instances)

    def register_instances(self, load_balancer_name, instances):
        return self.conn.register_instances(load_balancer_name, instances)

    def create_load_balancer_listeners(self, name, listeners):
        return self.conn.create_load_balancer_listeners(name, listeners)

    def delete_load_balancer_listeners(self, name, ports):
        return self.conn.delete_load_balancer_listeners(name, ports)

    def configure_health_check(self, name, health_check):
        return self.conn.configure_health_check(name, health_check)

    def describe_instance_health(self, load_balancer_name, instances=None):
        obj = self.conn.describe_instance_health(load_balancer_name, instances)
        if self.saveclcdata:
            self.__save_json__(obj, "mockdata/ELB_Instances.json")
        return obj
Пример #6
0
lg_instance.add_tag(TAGK, TAGV)
time.sleep(5)
print lg_instance.id
print lg_instance.dns_name
print lg_instance.tags
print 'Creating ELB'
# initialize elastc load balancer
conn2 = ELBConnection(os.environ['AWS_ACCESS_KEY_ID'], os.environ['AWS_SECRET_KEY'])
# set heartbeat
page = 'HTTP:80' + '/heartbeat?lg=' + lg_instance.dns_name
hc = HealthCheck(interval=20, healthy_threshold=3, unhealthy_threshold=5, target=page)
# set port 80
elb = conn2.create_load_balancer('elb', [ZONE], [(80, 80, 'http')])
# allow all traffic
conn2.apply_security_groups_to_lb('elb', [sg.id])
conn2.configure_health_check('elb', hc)
print elb.dns_name
print 'Creating ASG'
# initialize launch config
conn3 = AutoScaleConnection(os.environ['AWS_ACCESS_KEY_ID'], os.environ['AWS_SECRET_KEY'])
config = LaunchConfiguration(name='config', image_id=DC_IMAGE, security_groups=sgs,
							 instance_type=TYPE, instance_monitoring=True)
conn3.create_launch_configuration(config)
# initialize auto scaling group
ag = AutoScalingGroup(connection=conn3, name='gp', load_balancers=['elb'], availability_zones=[ZONE],
                      health_check_type='ELB', health_check_period=60, launch_config=config,
					  min_size=2, max_size=5, desired_capacity=2,
					  tags=[Tag(key=TAGK, value=TAGV, propagate_at_launch=True,
								resource_id='gp', resource_type='auto-scaling-group')])
conn3.create_auto_scaling_group(ag)
# define the scaling policies
Пример #7
0
class AutoScale:

    def __init__(self, args):
        """
        Initializing basic variables needed for auto scaling
        """
        self.configs                = ConfigParser.RawConfigParser()
        self.args                   = args
        self.test_props             = {}
        self.props                  = {}
        self.ec2_connection         = EC2Connection(self.args.access_key, self.args.secret_key)
        self.autoscale_connection   = AutoScaleConnection(self.args.access_key, self.args.secret_key)
        self.elb_connection         = ELBConnection(self.args.access_key, self.args.secret_key)
        self.cw_connection          = CloudWatchConnection(self.args.access_key, self.args.secret_key)
        self.firstInstance          = None
        self.launchConfiguration    = None
        self.healthCheck            = None

    def loadConfigs(self):
        """
        FIX ME: Currently doesnt do anything
        This method will load the configurations from boto config file if present else will 
        accept parameters passed by user.
        """
        if os.path.isfile("/etc/boto.cfg"):
            self.configs.read("/etc/boto.cfg")
            conf = self.configs.sections()
            self.populateConfigs(conf)
        if os.path.isfile("~/.boto"):
            self.configs.read("~/.boto")
            conf = self.configs.sections()
            self.populateConfigs(conf)
            
        print ">>> Loaded configs"
            
    def populateConfigs(self, sections):
        for section in sections:
            self.boto_props[section] = self.configs.items(section)
            for item in self.boto_props[section]:
                key, value = item
                if not self.props.has_key(key):
                    self.props[key] = value

    def createLaunchConfiguration(self, lc_name, ami_id, key_name):
        """
        Creates launch configuration for the auto scaling cluster
        """
        self.launchConfiguration = LaunchConfiguration(name     = lc_name, 
                                                       image_id = ami_id, 
                                                       key_name = key_name)
        self.autoscale_connection.create_launch_configuration(self.launchConfiguration)
        print ">>> Created launch configuration: " + lc_name

    def createAutoScaleGroup(self, asg_name):
        """
        Create a Auto scaling group for the auto scaling cluster
        """
        autoScalingGroup = AutoScalingGroup(group_name         = asg_name, 
                                            load_balancers     = [self.args.lb_name], 
                                            launch_config      = self.launchConfiguration, 
                                            min_size           = self.args.min_size, 
                                            max_size           = self.args.max_size, 
                                            availability_zones = ['us-east-1a'])
        self.autoscale_connection.create_auto_scaling_group(autoScalingGroup)
        print ">>> Created auto scaling group: " + asg_name

    def createTrigger(self, trigger_name, measure, asg_name):
        """
        Trigger to spawn new instances as per specific metrics
        """
        alarm_actions = []
        dimensions = {"AutoScalingGroupName" : asg_name}
        policies = self.autoscale_connection.get_all_policies(as_group=self.args.asg_name, policy_names=[self.args.asp_name])
        for policy in policies:
            alarm_actions.append(policy.policy_arn)
        alarm = MetricAlarm(name                = trigger_name, 
                            namespace           = "AWS/EC2", 
                            metric              = measure, 
                            statistic           = "Average", 
                            comparison          = ">=", 
                            threshold           = 50, 
                            period              = 60, 
                            unit                = "Percent",
                            evaluation_periods  = 2,  
                            alarm_actions       = alarm_actions, 
                            dimensions          = dimensions)
        
        self.cw_connection.create_alarm(alarm)
        print ">>> Created trigger: "+self.args.trigger

    def createAutoScalePolicy(self, asp_name):
        """
        Creates a Auto scaling policy to Add/Remove a instance from auto scaling cluster
        """
        self.autoScalingUpPolicy = ScalingPolicy(name                 = asp_name+'-up',
                                                 adjustment_type      = "ChangeInCapacity", 
                                                 as_name              = self.args.asg_name, 
                                                 scaling_adjustment   = 1, 
                                                 cooldown             = 180)
        self.autoScalingDownPolicy = ScalingPolicy(name                 = asp_name+'-down',
                                                   adjustment_type      = "ChangeInCapacity", 
                                                   as_name              = self.args.asg_name, 
                                                   scaling_adjustment   = -1, 
                                                   cooldown             = 180)

        self.autoscale_connection.create_scaling_policy(self.autoScalingUpPolicy)
        self.autoscale_connection.create_scaling_policy(self.autoScalingDownPolicy)
        
        print ">>> Created auto scaling policy: " + asp_name
    
    def configureHealthCheck(self, target):
        """
        Configures health check for the cluster
        """
        self.healthCheck = HealthCheck(target   = target, 
                                       timeout  = 5)
        print ">>> Configured health check for: " + target
        
    def createLoadBalancer(self, lb_name, region, lb_port, instance_port, protocol):
        """
        Creates a load balancer for cluster
        """
        listener = (int(lb_port), int(instance_port), protocol)
        tuple_list =[]
        tuple_list.append(listener)
        lbs = self.elb_connection.get_all_load_balancers()
        for lb in lbs:
            if lb.name != lb_name:
                self.elb_connection.create_load_balancer(lb_name, [region], tuple_list)
                self.elb_connection.configure_health_check(name         = lb_name, 
                                                           health_check = self.healthCheck)
                print ">>> Created load balancer: " + lb_name
            else:
                print "Load balancer with name '"+lb_name+"' already exists"
        
    def startInstance(self, image_id, key_name, region, instance_type):
        """
        Starts the first instance which will be serving requests irrespective of auto scaling 
        instances.
        """
        reservation = self.ec2_connection.run_instances(image_id=image_id, min_count=1, max_count=1, placement=region, key_name=key_name, instance_type=instance_type)
#        for instance in reservation.instances:
#            instance.add_tag('node', '0')
#            break

        self.firstInstance = reservation.instances[0].id.split('\'')[0]
        print ">>> Started instance: ", self.firstInstance
    
    def registerInstanceToELB(self, lb_name):
        """
        Register the first instance started to the Elastic Load Balancer.
        """
        self.elb_connection.register_instances(load_balancer_name = lb_name, 
                                               instances          = [self.firstInstance])
        print ">>> Registered instance '",self.firstInstance,"' to load balancer '"+lb_name+"'"
    
    def setUp(self):
        """
        Set's up the auto scaling for the application
        """
        # STEP 1: Load the configurations
        self.loadConfigs()
        # STEP 2: Configure the health check for the instances
        self.configureHealthCheck(self.args.lb_target)
        # STEP 3: Create a load balancer
        self.createLoadBalancer(self.args.lb_name, self.args.region, self.args.lb_port, self.args.instance_port, self.args.protocol)
        # STEP 4: Start the first instance
        self.startInstance(self.args.ami_id, self.args.key_name, self.args.region, self.args.instance_type)
        # STEP 5: Register the instance to the load balancer created in STEP 4
        self.registerInstanceToELB(self.args.lb_name)
        # STEP 6: Create launch configuration to launch instances by auto scale
        self.createLaunchConfiguration(self.args.lc_name, self.args.ami_id, self.args.key_name)
        # STEP 7: Create a auto scale group which will manage the instances started by auto scaling
        self.createAutoScaleGroup(self.args.asg_name)
        # STEP 8: Create a auto scaling policy to say add/remove a node
        self.createAutoScalePolicy(self.args.asp_name)
        # STEP 9: Create a trigger, so that auto scaling can trigger it to start 
        # or remove a instance from auto scaling group 
        self.createTrigger(self.args.trigger, self.args.measure, self.args.asg_name)