Using kubernetes application.responsive.dev with risingwave.risingwavelabs.com

Question

Pulumi · Accepted Answer

To deploy an application in Kubernetes and configure it with two different domain names (application.responsive.dev and risingwave.risingwavelabs.com), you will need to set up a Kubernetes cluster and create the necessary resources such as Deployments, Services, and Ingress. The application will be run as a Deployment, exposing a Service which is then made accessible via an Ingress that maps the two domains to the service.

Below, I'll provide you with a simple Pulumi program written in TypeScript that performs the following actions:

1. Creates a Kubernetes Deployment to run your application's Docker image.
2. Exposes your application through a Kubernetes Service.
3. Configures an Ingress resource to make your Service accessible from the domain names specified.

Let's get started with a detailed explanation and the Pulumi program to accomplish this.

### Detailed Explanation
#### Kubernetes Deployment
The `Deployment` is a Kubernetes resource that manages a set of replicated Pods. The Deployment ensures that a specified number of Pods are running at any given time, handling the creation, update, and removal of Pods transparently.

#### Kubernetes Service
The `Service` resource in Kubernetes abstracts a way to expose an application running on a set of Pods as a network service. The Service selects Pods based on their labels and provides a consistent endpoint for accessing them.

#### Kubernetes Ingress
The `Ingress` resource provides HTTP routing to Services based on requested hostnames (domains). This lets you configure external access to your Service by mapping domain names to the Service.

### Pulumi Program

```typescript
import * as k8s from "@pulumi/kubernetes";

// Image for the application to be deployed
const appImage = "myapplication:latest"; // Replace with your actual image

// Create a Kubernetes Deployment for the application
const appDeployment = new k8s.apps.v1.Deployment("appDeployment", {
    spec: {
        selector: { matchLabels: { app: "myapplication" } },
        replicas: 2, // Specify the number of replicas
        template: {
            metadata: { labels: { app: "myapplication" } },
            spec: {
                containers: [{
                    name: "myapplication",
                    image: appImage,
                    ports: [{ name: "http", containerPort: 80 }] // Set the container port
                }],
            },
        },
    },
});

// Create a Kubernetes Service to expose the application Deployment
const appService = new k8s.core.v1.Service("appService", {
    spec: {
        ports: [{ name: "http", port: 80 }],
        selector: { app: "myapplication" },
        type: "ClusterIP", // Cluster-internal IP only
    },
});

// Create an Ingress to expose the Service to the internet under the specified domain names
const appIngress = new k8s.networking.v1.Ingress("appIngress", {
    metadata: {
        annotations: {
            // Use the appropriate Ingress class or any cloud-specific annotations as needed
            "kubernetes.io/ingress.class": "nginx", // Assuming you're using NGINX Ingress controller
        },
    },
    spec: {
        rules: [{
            host: "application.responsive.dev",
            http: {
                paths: [{
                    path: "/",
                    pathType: "Prefix",
                    backend: {
                        service: {
                            name: appService.metadata.name,
                            port: { name: "http" },
                        },
                    },
                }],
            },
        },
        {
            host: "risingwave.risingwavelabs.com",
            http: {
                paths: [{
                    path: "/",
                    pathType: "Prefix",
                    backend: {
                        service: {
                            name: appService.metadata.name,
                            port: { name: "http" },
                        },
                    },
                }],
            },
        }],
    },
});

// Export the Ingress's IP or hostname to access the application
export const ingressEndpoint = appIngress.status.loadBalancer.ingress[0].hostname || appIngress.status.loadBalancer.ingress[0].ip;
```

This Pulumi program creates the core resources needed to deploy an application on a Kubernetes cluster and make it accessible via two domains. The `Ingress` is set up with annotations that assume you are using an NGINX Ingress controller, which might need to be adjusted depending on your actual Kubernetes environment (e.g., in cloud environments like AWS, Azure, or GCP, you would likely use their specific Ingress annotations). The exported `ingressEndpoint` will provide you with the external IP or the hostname through which you can access the application, once the `Ingress` resource is live and the load balancer is provisioned.

Make sure to replace `myapplication:latest` with the actual Docker image you want to deploy. Also, adjust the container port if your app doesn't serve content over port 80. The Ingress annotations and service type may need to be updated based on your actual cloud or on-premise environment.

Remember, this is a simple starting point. Depending on your application's complexity and the specific requirements, you might need additional configurations like setting environment variables, volumes, secrets, resource limits, or even more advanced Ingress features like TLS termination.