Using aws alb with parameter

Question

Pulumi · Accepted Answer

To create an AWS Application Load Balancer (ALB) with parameters using Pulumi, you can use the `aws.alb.LoadBalancer` resource to define the Load Balancer itself and `aws.alb.TargetGroup` plus `aws.alb.Listener` for routing and handling incoming requests. Below you will find a Pulumi program written in TypeScript that demonstrates how to create an ALB with a simple parameter configuration.

Before diving into the code, here's a quick overview of the key resources:

- **LoadBalancer**: Represents an AWS ALB that will distribute incoming application traffic across multiple targets, such as EC2 instances.
- **TargetGroup**: Defines a group of targets, such as EC2 instances, that will receive requests forwarded by the LoadBalancer.
- **Listener**: Listens for incoming connections to the LoadBalancer and forwards them to one or more TargetGroups based on rules.

Here's how you set up an AWS Application Load Balancer using Pulumi:

```typescript
import * as pulumi from '@pulumi/pulumi';
import * as aws from '@pulumi/aws';

// Create a new security group for the ALB
const albSecurityGroup = new aws.ec2.SecurityGroup('albSecurityGroup', {
    description: 'Allow inbound access to the ALB',
    ingress: [
        {
            description: 'Allow HTTP',
            fromPort: 80,
            toPort: 80,
            protocol: 'tcp',
            cidrBlocks: ['0.0.0.0/0'],
        },
    ],
});

// Create an Application Load Balancer
const appLoadBalancer = new aws.alb.LoadBalancer('appLoadBalancer', {
    internal: false,
    subnets: ['subnet-xxxxxxxxxxxxx'], // Specify your subnet IDs
    securityGroups: [albSecurityGroup.id],
    enableHttp2: true,
    loadBalancerType: 'application',
});

// Create a target group for the Load Balancer
const appTargetGroup = new aws.alb.TargetGroup('appTargetGroup', {
    port: 80,
    protocol: 'HTTP',
    targetType: 'ip',
    vpcId: 'vpc-xxxxxxxxxxxxx', // Specify your VPC ID
});

// Create a listener for the Load Balancer
const appListener = new aws.alb.Listener('appListener', {
    loadBalancerArn: appLoadBalancer.arn,
    port: 80,
    defaultActions: [{
        type: 'forward',
        targetGroupArn: appTargetGroup.arn,
    }],
});

// Export the DNS name of the Load Balancer
export const albDnsName = appLoadBalancer.dnsName;
```

In this program:

- We first create a security group for the ALB with HTTP access allowed from anywhere.
- We then set up the ALB itself, specifying whether it's internal, the subnets it's associated with, the security groups, and enabling HTTP/2 for better performance.
- Next, we create a target group for the ALB to forward requests to. The target group needs to specify the port, protocol, target type, and the VPC it's associated with.
- Then, we set up a listener on the ALB that listens on port 80. The listener is configured with a default action to forward any requests to our `appTargetGroup`.
- Finally, we export the DNS name of the ALB, which can be used to access the services behind it.

After you've set up the Pulumi program, you need to run `pulumi up` to create these resources in AWS. If you want to customize the configuration, such as changing ports, adding HTTPS, or specifying different routing rules, you can modify the `appListener` and `appTargetGroup` resources accordingly. Remember to replace the subnet and VPC IDs with those from your own AWS environment.