Using kubernetes projectcalico.org with traefik

Question

Pulumi · Accepted Answer

To integrate projectcalico.org with Traefik in a Kubernetes cluster using Pulumi, you'll need to set up a few key resources:

1. A Kubernetes Namespace, where the Traefik Ingress controller will live.
2. The Traefik Ingress controller, which will manage ingress resources for your applications.
3. Calico, as the CNI (Container Network Interface) plugin that provides the network connectivity for your pods and enforces network policies.

Here's a breakdown of how you can set this up using Pulumi and TypeScript:

- **Namespace**: Namespaces in Kubernetes serve as a way to divide cluster resources between multiple users.
- **Traefik Ingress Controller**: This is the actual Ingress controller that will manage your network traffic. It watches for resources with the kind "Ingress" and processes them according to their rules.
- **Calico**: This is not directly provisioned through Pulumi in the script below but is rather something you would install on your cluster separately. Calico is a CNI plugin for Kubernetes that provides advanced networking features like network policies to manage and secure traffic between pods.

Let's dive into the code where we're going to:

- Use the `kubernetes` package to create Kubernetes resources.
- Create a namespace for Traefik.
- Deploy Traefik using its Helm chart. Pulumi has support for Helm charts, which are packages of pre-configured Kubernetes resources.

Here's the TypeScript program that sets this up:

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

// Create a Kubernetes Namespace for Traefik
const traefikNamespace = new k8s.core.v1.Namespace('traefik-namespace', {
    metadata: { name: 'traefik' },
});

// Deploy Traefik using the Helm Chart
const traefikChart = new k8s.helm.v3.Chart('traefik', {
    chart: 'traefik',
    version: '9.18.2',
    fetchOpts: {
        repo: 'https://helm.traefik.io/traefik',
    },
    namespace: traefikNamespace.metadata.name,
}, { dependsOn: [traefikNamespace] });

// Export the public IP address of the Traefik service
export const publicIp = traefikChart.getResource('v1/Service', 'traefik-traefik').status.apply(status => status.loadBalancer.ingress[0].ip);

```

In this program:
- We use the `@pulumi/kubernetes` package to interact with Kubernetes resources.
- We create a namespace for Traefik called `traefik`.
- We deploy Traefik using its Helm chart. We specify the version of the chart to ensure we get a specific release.
- Since resources in Kubernetes are often interdependent, we use the `dependsOn` option to ensure that Pulumi creates the namespace before attempting to deploy the Helm chart.
- Finally, we export the public IP address of the Traefik Ingress service. This allows us to easily access the IP address once the deployment is complete.

Please ensure you have Pulumi and Kubernetes configured correctly for your environment where the script will be executed.

Regarding Calico, you should follow the installation instructions provided by the Calico documentation to set it up on your Kubernetes cluster:
[Installing Calico for policy and networking](https://projectcalico.docs.tigera.io/getting-started/kubernetes)

As the installation specifics may vary depending on the environment and other considerations, the instructions for installing Calico are not included in this script. Typically, Calico is installed using manifest files provided by the Calico project, which you would apply to your Kubernetes cluster with `kubectl apply`.

Once you have Calico and Traefik set up with the code above, Calico will handle the networking according to the policies you define, while Traefik will manage how external traffic is routed to your applications.

Remember to install the necessary Pulumi CLI tools and configure access to your Kubernetes cluster before running this script. You can then run the program with the `pulumi up` command to deploy these resources.