Deploy the hadoop-yarn helm chart on Oracle Kubernetes Engine (OKE)

Question

Pulumi · Accepted Answer

To deploy the Hadoop YARN Helm chart on Oracle Kubernetes Engine (OKE), we will use Pulumi to orchestrate the necessary cloud resources. The Pulumi program will perform the following steps:

1. Provision an OKE cluster, if one does not already exist.
2. Deploy the Helm chart for Hadoop YARN to the cluster.

Below is a Pulumi TypeScript program that carries out these steps. The program uses the `oci` and `kubernetes` packages from Pulumi to interact with the Oracle Cloud Infrastructure and to work with Kubernetes resources, respectively.

### Detailed Explanation

First, we will write the Pulumi script to instantiate a new OKE cluster using the `oci.ContainerEngine.Cluster` resource. Once the OKE cluster is up and running, we will configure Pulumi to use the Kubernetes provider to connect to the newly created OKE cluster.

Afterward, we will deploy the Hadoop YARN Helm chart using the `kubernetes.helm.v3.Chart` resource. The chart is specified by its repository and name, and in this case, you would replace `repoUrl` with the URL of the Helm chart repository that contains the Hadoop YARN chart and `chartName` with the name of the chart in that repository.

Here's the full Pulumi program:

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

const name = "hadoop-yarn-oke";

// Create an Oracle Cloud Infrastructure Container Engine for Kubernetes (OKE) cluster
const cluster = new oci.ContainerEngine.Cluster(`${name}-cluster`, {
    /* Other required properties like compartmentId, vcnId, etc. */
    // As an example, we're just specifying the 'name' and 'kubernetesVersion'
    // You'll need to replace these values with actual configuration settings for your OCI environment
    name: `${name}-cluster`,
    kubernetesVersion: "v1.20.11", // Replace with the version you want to use
    /* Add additional configurations such as VCN configuration, node pool setup etc. */
});

// Obtain cluster kubeconfig to interact with the cluster using the Kubernetes provider
const kubeconfig = pulumi.
    all([cluster.id, cluster.name]).
    apply(([id, name]) => oci.ContainerEngine.getClusterKubeconfig({ id, name }));

const k8sProvider = new k8s.Provider(`${name}-k8sprovider`, {
    kubeconfig: kubeconfig,
}, { dependsOn: cluster });

// Repository URL where the Hadoop YARN Helm chart can be found
const repoUrl = "https://charts.example.com/";
// Name of the chart in the repository
const chartName = "hadoop-yarn";

// Deploy the Hadoop YARN Helm chart
const hadoopYarnChart = new k8s.helm.v3.Chart(`${name}-hadoop-yarn`, {
    chart: chartName,
    version: "1.2.3", // Replace with the specific chart version you want to deploy. If omitted, the latest version will be used.
    fetchOpts: {
        repo: repoUrl,
    },
}, { provider: k8sProvider });

// Export the cluster's kubeconfig and Helm release name
export const kubeconfigOutput = kubeconfig;
export const helmReleaseName = hadoopYarnChart.metadata.name;
```

This program sets up the necessary resources to deploy the Hadoop YARN Helm chart on an OKE cluster. Note that a real deployment would need the Oracle Cloud Infrastructure configuration information filled out, including compartment, virtual cloud network (VCN) info, and node pool configurations which are dependent on the specific OCI environment.

### Notes:

- Placeholders like `compartmentId`, `vcnId`, and specific OCI environment configurations must be replaced with actual values from your Oracle Cloud Infrastructure.
- You need to have Pulumi and Oracle Cloud Infrastructure Provider configured.
- The Helm chart version and name should be adjusted to suit the actual Hadoop YARN Helm chart you are using.
- The program above utilizes `kubeconfig` to connect to the Kubernetes cluster managed by Oracle. This file contains the necessary connection details for the cluster and must be handled securely.

**Note**: Ensure you review and understand the permissions and roles required both in Oracle Cloud Infrastructure and Kubernetes to deploy and manage resources.

After writing the program, you would run `pulumi up` to execute the script, which will create resources determined by the content of the script. Make sure to review the expected changes before confirming the Pulumi deployment.

If you encounter any specific errors or need further clarification on configuring the OCI provider, adjusting the Helm chart settings, or interpreting the output, don't hesitate to ask!