Alb

The Alb component lets you create a standalone Application Load Balancer that can be shared across multiple services.

Create a shared ALB

sst.config.ts

const vpc = new sst.aws.Vpc("MyVpc");

const alb = new sst.aws.Alb("SharedAlb", {
  vpc,
  domain: "app.example.com",
  listeners: [
    { port: 80, protocol: "http" },
    { port: 443, protocol: "https" },
  ],
});

Attach services to the ALB

sst.config.ts

new sst.aws.Service("Api", {
  cluster,
  image: "api:latest",
  loadBalancer: {
    instance: alb,
    rules: [
      { listen: "443/https", forward: "8080/http", conditions: { path: "/api/*" }, priority: 100 },
    ],
  },
});

Reference an existing ALB

sst.config.ts

const alb = sst.aws.Alb.get("SharedAlb", "arn:aws:elasticloadbalancing:...");

---

Constructor

new Alb(name, args, opts?)

Parameters

• name string

• args AlbArgs

• opts? ComponentResourceOptions

AlbArgs

domain?

Type string | Object

• aliases?

• cert?

• dns?

• name

Set a custom domain for the load balancer.

Automatically manages domains hosted on AWS Route 53, Cloudflare, and Vercel. For other providers, you’ll need to pass in a cert that validates domain ownership and add the DNS records.

{
  domain: "example.com"
}

For domains on Cloudflare:

{
  domain: {
    name: "example.com",
    dns: sst.cloudflare.dns()
  }
}

domain.aliases?

Type string[]

Alias domains that should also point to this load balancer.

domain.cert?

Type Input<string>

The ARN of an ACM certificate that proves ownership of the domain. By default, a certificate is created and validated automatically.

domain.dns?

Type false | sst.aws.dns | sst.cloudflare.dns | sst.vercel.dns

Default sst.aws.dns

The DNS provider to use. Defaults to AWS Route 53. Set to false for manual DNS setup.

domain.name

Type string

The custom domain name.

listeners

Type AlbListenerArgs[]

The listeners for the load balancer. Each entry creates a listener on the specified port and protocol.

{
  listeners: [
    { port: 80, protocol: "http" },
    { port: 443, protocol: "https" }
  ]
}

public?

Type Input<boolean>

Default true

Configure if the load balancer should be public (internet-facing) or private (internal).

When set to false, the load balancer endpoint will only be accessible within the VPC.

transform?

Type Object

• listener?

• loadBalancer?

• securityGroup?

Transform how this component creates its underlying resources.

transform.listener?

Type ListenerArgs | (args: ListenerArgs, opts: ComponentResourceOptions, name: string) => void

Transform the AWS Load Balancer listener resource.

transform.loadBalancer?

Type LoadBalancerArgs | (args: LoadBalancerArgs, opts: ComponentResourceOptions, name: string) => void

Transform the AWS Load Balancer resource.

transform.securityGroup?

Type SecurityGroupArgs | (args: SecurityGroupArgs, opts: ComponentResourceOptions, name: string) => void

Transform the AWS Security Group resource for the Load Balancer.

vpc

Type Vpc | Input<Object>

• id

• privateSubnets

• publicSubnets

The VPC to deploy the ALB in. Can be an SST Vpc component or a custom VPC configuration.

Using an SST Vpc component:

{
  vpc: myVpc
}

Using a custom VPC:

{
  vpc: {
    id: "vpc-0123456789abcdef0",
    publicSubnets: ["subnet-abc", "subnet-def"],
    privateSubnets: ["subnet-ghi", "subnet-jkl"]
  }
}

vpc.id

Type Input<string>

The VPC ID.

vpc.privateSubnets

Type Input<Input<string>[]>

The private subnet IDs.

vpc.publicSubnets

Type Input<Input<string>[]>

The public subnet IDs.

Properties

arn

Type Output<string>

The ARN of the load balancer.

dnsName

Type Output<string>

The DNS name of the load balancer.

nodes

Type Object

• listeners

• loadBalancer

• securityGroup

The underlying resources this component creates.

nodes.listeners

Type Record<string, Listener>

The AWS Listener resources, keyed by “PROTOCOLPORT” (e.g. “HTTPS443”).

nodes.loadBalancer

Type LoadBalancer

The AWS Load Balancer resource.

nodes.securityGroup

Type SecurityGroup

The AWS Security Group resource.

securityGroupId

Type Output<string>

The security group ID of the load balancer.

url

Type Output<string>

The URL of the load balancer. If a custom domain is set, this will be the custom domain URL (eg. https://app.example.com/). Otherwise, it’s the ALB’s DNS name.

zoneId

Type Output<string>

The zone ID of the load balancer.

SDK

Use the SDK in your runtime to interact with your infrastructure.

---

Links

This is accessible through the Resource object in the SDK.

• url string

  The URL of the load balancer. If a custom domain is set, this will be the custom domain URL (eg. https://app.example.com/). Otherwise, it’s the ALB’s DNS name.

Methods

getListener

getListener(protocol, port)

Parameters

• protocol string

• port number

Returns Listener

Get a specific listener by protocol and port.

const listener = alb.getListener("https", 443);

static get

Alb.get(name, loadBalancerArn, opts?)

Parameters

• name string

  The name of the component.

• loadBalancerArn Input<string>

  The ARN of the existing ALB.

• opts? ComponentResourceOptions

  Component resource options.

Returns Alb

Reference an existing ALB by its ARN.

const alb = sst.aws.Alb.get("SharedAlb", "arn:aws:elasticloadbalancing:...");

AlbListenerArgs

port

Type number

The port to listen on.

{
  port: 443
}

protocol

Type “https” | “http”

The protocol to listen on. Only http and https are supported (ALB-only).

{
  protocol: "https"
}