AWS::GlobalAccelerator Construct Library

---

cfn-resources: Stable

cdk-constructs: Stable


Introduction

AWS Global Accelerator (AGA) is a service that improves the availability and performance of your applications with local or global users.

It intercepts your user’s network connection at an edge location close to them, and routes it to one of potentially multiple, redundant backends across the more reliable and less congested AWS global network.

AGA can be used to route traffic to Application Load Balancers, Network Load Balancers, EC2 Instances and Elastic IP Addresses.

For more information, see the AWS Global Accelerator Developer Guide.

Example

Here’s an example that sets up a Global Accelerator for two Application Load Balancers in two different AWS Regions:

# Example automatically generated from non-compiling source. May contain errors.
import aws_cdk.aws_globalaccelerator as globalaccelerator
import aws_cdk.aws_globalaccelerator_endpoints as ga_endpoints
import aws_cdk.aws_elasticloadbalancingv2 as elbv2

# Create an Accelerator
accelerator = globalaccelerator.Accelerator(stack, "Accelerator")

# Create a Listener
listener = accelerator.add_listener("Listener",
    port_ranges=[globalaccelerator.PortRange(from_port=80), globalaccelerator.PortRange(from_port=443)
    ]
)

# Import the Load Balancers
nlb1 = elbv2.NetworkLoadBalancer.from_network_load_balancer_attributes(stack, "NLB1",
    load_balancer_arn="arn:aws:elasticloadbalancing:us-west-2:111111111111:loadbalancer/app/my-load-balancer1/e16bef66805b"
)
nlb2 = elbv2.NetworkLoadBalancer.from_network_load_balancer_attributes(stack, "NLB2",
    load_balancer_arn="arn:aws:elasticloadbalancing:ap-south-1:111111111111:loadbalancer/app/my-load-balancer2/5513dc2ea8a1"
)

# Add one EndpointGroup for each Region we are targeting
listener.add_endpoint_group("Group1",
    endpoints=[ga_endpoints.NetworkLoadBalancerEndpoint(nlb1)]
)
listener.add_endpoint_group("Group2",
    # Imported load balancers automatically calculate their Region from the ARN.
    # If you are load balancing to other resources, you must also pass a `region`
    # parameter here.
    endpoints=[ga_endpoints.NetworkLoadBalancerEndpoint(nlb2)]
)

Concepts

The Accelerator construct defines a Global Accelerator resource.

An Accelerator includes one or more Listeners that accepts inbound connections on one or more ports.

Each Listener has one or more Endpoint Groups, representing multiple geographically distributed copies of your application. There is one Endpoint Group per Region, and user traffic is routed to the closest Region by default.

An Endpoint Group consists of one or more Endpoints, which is where the user traffic coming in on the Listener is ultimately sent. The Endpoint port used is the same as the traffic came in on at the Listener, unless overridden.

Types of Endpoints

There are 4 types of Endpoints, and they can be found in the @aws-cdk/aws-globalaccelerator-endpoints package:

  • Application Load Balancers

  • Network Load Balancers

  • EC2 Instances

  • Elastic IP Addresses

Application Load Balancers

# Example automatically generated from non-compiling source. May contain errors.
alb = elbv2.ApplicationLoadBalancer(...)

listener.add_endpoint_group("Group",
    endpoints=[
        ga_endpoints.ApplicationLoadBalancerEndpoint(alb,
            weight=128,
            preserve_client_ip=True
        )
    ]
)

Network Load Balancers

# Example automatically generated from non-compiling source. May contain errors.
nlb = elbv2.NetworkLoadBalancer(...)

listener.add_endpoint_group("Group",
    endpoints=[
        ga_endpoints.NetworkLoadBalancerEndpoint(nlb,
            weight=128
        )
    ]
)

EC2 Instances

# Example automatically generated from non-compiling source. May contain errors.
instance = ec2.instance(...)

listener.add_endpoint_group("Group",
    endpoints=[
        ga_endpoints.InstanceEndpoint(instance,
            weight=128,
            preserve_client_ip=True
        )
    ]
)

Elastic IP Addresses

# Example automatically generated from non-compiling source. May contain errors.
eip = ec2.CfnEIP(...)

listener.add_endpoint_group("Group",
    endpoints=[
        ga_endpoints.CfnEipEndpoint(eip,
            weight=128
        )
    ]
)

Client IP Address Preservation and Security Groups

When using the preserveClientIp feature, AGA creates Elastic Network Interfaces (ENIs) in your AWS account, that are associated with a Security Group AGA creates for you. You can use the security group created by AGA as a source group in other security groups (such as those for EC2 instances or Elastic Load Balancers), if you want to restrict incoming traffic to the AGA security group rules.

AGA creates a specific security group called GlobalAccelerator for each VPC it has an ENI in (this behavior can not be changed). CloudFormation doesn’t support referencing the security group created by AGA, but this construct library comes with a custom resource that enables you to reference the AGA security group.

Call endpointGroup.connectionsPeer() to obtain a reference to the Security Group which you can use in connection rules. You must pass a reference to the VPC in whose context the security group will be looked up. Example:

# Example automatically generated from non-compiling source. May contain errors.
# ...

# Non-open ALB
alb = elbv2.ApplicationLoadBalancer(stack, "ALB")

endpoint_group = listener.add_endpoint_group("Group",
    endpoints=[
        ga_endpoints.ApplicationLoadBalancerEndpoint(alb,
            preserve_client_ips=True
        )
    ]
)

# Remember that there is only one AGA security group per VPC.
aga_sg = endpoint_group.connections_peer("GlobalAcceleratorSG", vpc)

# Allow connections from the AGA to the ALB
alb.connections.allow_from(aga_sg, Port.tcp(443))