aws-cdk-lib.aws_elasticloadbalancing

Amazon Elastic Load Balancing Construct Library

The aws-cdk-lib/aws-elasticloadbalancing package provides constructs for configuring classic load balancers.

Configuring a Load Balancer

Load balancers send traffic to one or more AutoScalingGroups. Create a load balancer, set up listeners and a health check, and supply the fleet(s) you want to load balance to in the targets property. If you want the load balancer to be accessible from the internet, set internetFacing: true.

declare const vpc: ec2.IVpc;
const lb = new elb.LoadBalancer(this, 'LB', {
  vpc,
  internetFacing: true,
  healthCheck: {
    port: 80,
  },
});

declare const myAutoScalingGroup: autoscaling.AutoScalingGroup;
lb.addTarget(myAutoScalingGroup);
lb.addListener({
  externalPort: 80,
});

# vpc: ec2.IVpc

# my_auto_scaling_group: autoscaling.AutoScalingGroup

lb = elb.LoadBalancer(self, "LB",
    vpc=vpc,
    internet_facing=True,
    health_check=elb.HealthCheck(
        port=80
    )
)
lb.add_target(my_auto_scaling_group)
lb.add_listener(
    external_port=80
)

IVpc vpc;

AutoScalingGroup myAutoScalingGroup;

LoadBalancer lb = LoadBalancer.Builder.create(this, "LB")
        .vpc(vpc)
        .internetFacing(true)
        .healthCheck(HealthCheck.builder()
                .port(80)
                .build())
        .build();
lb.addTarget(myAutoScalingGroup);
lb.addListener(LoadBalancerListener.builder()
        .externalPort(80)
        .build());

IVpc vpc;

AutoScalingGroup myAutoScalingGroup;

var lb = new LoadBalancer(this, "LB", new LoadBalancerProps {
    Vpc = vpc,
    InternetFacing = true,
    HealthCheck = new HealthCheck {
        Port = 80
    }
});
lb.AddTarget(myAutoScalingGroup);
lb.AddListener(new LoadBalancerListener {
    ExternalPort = 80
});

var vpc IVpc

var myAutoScalingGroup AutoScalingGroup

lb := elb.NewLoadBalancer(this, jsii.String("LB"), &LoadBalancerProps{
	Vpc: Vpc,
	InternetFacing: jsii.Boolean(true),
	HealthCheck: &HealthCheck{
		Port: jsii.Number(80),
	},
})
lb.AddTarget(myAutoScalingGroup)
lb.AddListener(&LoadBalancerListener{
	ExternalPort: jsii.Number(80),
})

The load balancer allows all connections by default. If you want to change that, pass the allowConnectionsFrom property while setting up the listener:

declare const mySecurityGroup: ec2.SecurityGroup;
declare const lb: elb.LoadBalancer;
lb.addListener({
  externalPort: 80,
  allowConnectionsFrom: [mySecurityGroup],
});

# my_security_group: ec2.SecurityGroup
# lb: elb.LoadBalancer

lb.add_listener(
    external_port=80,
    allow_connections_from=[my_security_group]
)

SecurityGroup mySecurityGroup;
LoadBalancer lb;

lb.addListener(LoadBalancerListener.builder()
        .externalPort(80)
        .allowConnectionsFrom(List.of(mySecurityGroup))
        .build());

SecurityGroup mySecurityGroup;
LoadBalancer lb;

lb.AddListener(new LoadBalancerListener {
    ExternalPort = 80,
    AllowConnectionsFrom = new [] { mySecurityGroup }
});

var mySecurityGroup SecurityGroup
var lb LoadBalancer

lb.AddListener(&LoadBalancerListener{
	ExternalPort: jsii.Number(80),
	AllowConnectionsFrom: []IConnectable{
		mySecurityGroup,
	},
})

Adding Ec2 Instance as a target for the load balancer

You can add an EC2 instance to the load balancer by calling using new InstanceTarget as the argument to addTarget():

declare const vpc: ec2.IVpc;
const lb = new elb.LoadBalancer(this, 'LB', {
  vpc,
  internetFacing: true,
});

// instance to add as the target for load balancer.
const instance = new ec2.Instance(this, 'targetInstance', {
  vpc: vpc,
  instanceType: ec2.InstanceType.of(ec2.InstanceClass.BURSTABLE2, ec2.InstanceSize.MICRO),
  machineImage: new ec2.AmazonLinuxImage({ generation: ec2.AmazonLinuxGeneration.AMAZON_LINUX_2 }),
});
lb.addTarget(new elb.InstanceTarget(instance));

# vpc: ec2.IVpc

lb = elb.LoadBalancer(self, "LB",
    vpc=vpc,
    internet_facing=True
)

# instance to add as the target for load balancer.
instance = ec2.Instance(self, "targetInstance",
    vpc=vpc,
    instance_type=ec2.InstanceType.of(ec2.InstanceClass.BURSTABLE2, ec2.InstanceSize.MICRO),
    machine_image=ec2.AmazonLinuxImage(generation=ec2.AmazonLinuxGeneration.AMAZON_LINUX_2)
)
lb.add_target(elb.InstanceTarget(instance))

IVpc vpc;

LoadBalancer lb = LoadBalancer.Builder.create(this, "LB")
        .vpc(vpc)
        .internetFacing(true)
        .build();

// instance to add as the target for load balancer.
Instance instance = Instance.Builder.create(this, "targetInstance")
        .vpc(vpc)
        .instanceType(InstanceType.of(InstanceClass.BURSTABLE2, InstanceSize.MICRO))
        .machineImage(AmazonLinuxImage.Builder.create().generation(AmazonLinuxGeneration.AMAZON_LINUX_2).build())
        .build();
lb.addTarget(new InstanceTarget(instance));

IVpc vpc;

var lb = new LoadBalancer(this, "LB", new LoadBalancerProps {
    Vpc = vpc,
    InternetFacing = true
});

// instance to add as the target for load balancer.
var instance = new Instance(this, "targetInstance", new InstanceProps {
    Vpc = vpc,
    InstanceType = InstanceType.Of(InstanceClass.BURSTABLE2, InstanceSize.MICRO),
    MachineImage = new AmazonLinuxImage(new AmazonLinuxImageProps { Generation = AmazonLinuxGeneration.AMAZON_LINUX_2 })
});
lb.AddTarget(new InstanceTarget(instance));

var vpc IVpc

lb := elb.NewLoadBalancer(this, jsii.String("LB"), &LoadBalancerProps{
	Vpc: Vpc,
	InternetFacing: jsii.Boolean(true),
})

// instance to add as the target for load balancer.
instance := ec2.NewInstance(this, jsii.String("targetInstance"), &InstanceProps{
	Vpc: vpc,
	InstanceType: ec2.InstanceType_Of(ec2.InstanceClass_BURSTABLE2, ec2.InstanceSize_MICRO),
	MachineImage: ec2.NewAmazonLinuxImage(&AmazonLinuxImageProps{
		Generation: ec2.AmazonLinuxGeneration_AMAZON_LINUX_2,
	}),
})
lb.AddTarget(elb.NewInstanceTarget(instance))

Types

Name	Kind	Summary
LoadBalancer	Construct (L2)	A load balancer with a single listener.
CfnLoadBalancer	Construct (L1)	Specifies a Classic Load Balancer.
CfnLoadBalancer.AccessLoggingPolicyProperty	Struct	Specifies where and how access logs are stored for your Classic Load Balancer.
CfnLoadBalancer.AppCookieStickinessPolicyProperty	Struct	Specifies a policy for application-controlled session stickiness for your Classic Load Balancer.
CfnLoadBalancer.ConnectionDrainingPolicyProperty	Struct	Specifies the connection draining settings for your Classic Load Balancer.
CfnLoadBalancer.ConnectionSettingsProperty	Struct	Specifies the idle timeout value for your Classic Load Balancer.
CfnLoadBalancer.HealthCheckProperty	Struct	Specifies health check settings for your Classic Load Balancer.
CfnLoadBalancer.LBCookieStickinessPolicyProperty	Struct	Specifies a policy for duration-based session stickiness for your Classic Load Balancer.
CfnLoadBalancer.ListenersProperty	Struct	Specifies a listener for your Classic Load Balancer.
CfnLoadBalancer.PoliciesProperty	Struct	Specifies policies for your Classic Load Balancer.
CfnLoadBalancer.SourceSecurityGroupProperty	Struct
CfnLoadBalancerProps	Struct	Properties for defining a CfnLoadBalancer.
HealthCheck	Struct	Describe the health check to a load balancer.
ILoadBalancer	Interface	Represents a load balancer.
ILoadBalancerTarget	Interface	Interface that is going to be implemented by constructs that you can load balance to.
InstanceTarget	Class	An EC2 instance that is the target for load balancing.
ListenerPort	Class	Reference to a listener's port just created.
LoadBalancerListener	Struct	Add a backend to the load balancer.
LoadBalancerProps	Struct	Construction properties for a LoadBalancer.
LoadBalancingProtocol	Enum