Deploy the fluentd-kubernetes-daemonset helm chart on Rancher

Question

Pulumi · Accepted Answer

To deploy the `fluentd-kubernetes-daemonset` Helm chart on a Kubernetes cluster managed by Rancher using Pulumi, we will need to first ensure that we have Rancher set up with a Kubernetes cluster. We'll then use Pulumi's rancher2 provider to interact with the Rancher API. Our goal is to deploy a Helm chart, which is essentially a packaged set of Kubernetes resources.

Helm charts are deployed using the `helm.Release` resource in Pulumi. Helm is a package manager for Kubernetes and allows us to install and manage Kubernetes applications. `fluentd-kubernetes-daemonset` is one such application that runs Fluentd as a DaemonSet to collect Kubernetes logs.

Below is a program written in TypeScript that demonstrates how to deploy a Helm chart to a Kubernetes cluster managed by Rancher using Pulumi. Before running this code, ensure that you have configured Pulumi with access to your Rancher-managed Kubernetes cluster.

Let's start by installing the required dependencies:

```shell
npm install @pulumi/rancher2 @pulumi/kubernetes
```

You may also need to configure your Pulumi provider to interact with your Rancher instance. Now here's the TypeScript program:

```typescript
import * as rancher2 from "@pulumi/rancher2";
import * as k8s from "@pulumi/kubernetes";

// Assuming you're already logged in to Rancher2 and have set your kubeconfig
// appropriately, Pulumi will use that context to create resources.
// Please ensure you have the correct context set for your kubectl if you
// have multiple clusters or change context often.

// The name of the rancher2 cluster which you wish to deploy the helm chart to
const clusterName = "your-cluster-name";

// Fetch the cluster from Rancher where the Helm chart will be deployed
const cluster = rancher2.getCluster({ name: clusterName });

// Since Helm charts might need to be deployed into a specific namespace,
// and a specific one might be required or desired, we ensure its creation.
const namespace = new k8s.core.v1.Namespace("fluentd-namespace", {
    metadata: {
        // Replace with the desired namespace name
        name: "fluentd"
    }
}, {provider: cluster.provider}); // This ensures the namespace is created in the right cluster

// Deploy fluentd-kubernetes-daemonset chart using a Helm Release
const fluentdHelmChart = new k8s.helm.v3.Release("fluentd-release", {
    namespace: namespace.metadata.name,
    chart: "fluentd-kubernetes-daemonset",
    // You can specify the repository for the Helm chart if it's not in the default repo
    repositoryOpts: {
        repo: "https://charts.fluentd.io"
    },
    values: {
        // You can specify the values for the Helm chart here, as needed.
        // This will depend on the fluentd-kubernetes-daemonset chart's available values
        // For example, you might want to configure the backend or resources.
    }
}, {provider: cluster.provider}); // This ensures the helm chart is deployed to the right cluster

// Export the URL for the fluentd service deployed by the Helm chart if it creates one
export const fluentdServiceUrl = namespace.metadata.name.apply(nsName => `http://${nsName}.svc.cluster.local`);
```

In this code:

- We import the `@pulumi/rancher2` and `@pulumi/kubernetes` modules.
- We retrieve the cluster information from Rancher using `rancher2.getCluster`.
- We ensure the creation of the namespace where the `fluentd-kubernetes-daemonset` will be deployed using the `k8s.core.v1.Namespace` resource.
- We deploy the Helm chart with `k8s.helm.v3.Release` which is the Pulumi resource for deploying Helm charts. The chart is specified by its name and optionally the repository if it's not hosted in the Helm's default repository.
- We pass the configuration under `values` which are specific to the `fluentd-kubernetes-daemonset` Helm chart. These would control various aspects of Fluentd like backend configuration, resources, etc.
- We also assign the `provider` option to ensure that the resources are created in the cluster that's managed by Rancher.
- Finally, we export the potential URL for a service deployed by the helm chart that can be used to access Fluentd, if such a service is defined by the chart.

Before running this code using Pulumi, you should replace placeholders like `your-cluster-name` with actual values from your Rancher-managed Kubernetes cluster. Make sure you have cluster admin access and the correct kubeconfig context selected.

Please note that the `values` provided to the Helm chart should be customized according to your specific requirements for `fluentd`, and you might want to consult the chart's documentation to understand what options are available to you.

To run this Pulumi program, you'll want to follow the Pulumi CLI instructions for creating a new project, running `pulumi up` to create the resources, and then managing and maintaining your infrastructure as needed.