Deploy the stackdriver-metrics-adapter helm chart on Opensshift

Question

Pulumi · Accepted Answer

To deploy the `stackdriver-metrics-adapter` Helm chart on OpenShift using Pulumi, we'll use the Pulumi Kubernetes provider. This provider allows us to manage Kubernetes resources, including installing Helm charts.

Before we start with the Pulumi TypeScript code, here are the steps we will take:

1. **Create a new Pulumi project**: This will be our working directory and the environment for our infrastructure code.
2. **Install the necessary Pulumi packages**: For Kubernetes support, we need the `@pulumi/kubernetes` package which provides us with the Kubernetes resources.
3. **Define the Helm Chart resource**: In the Pulumi program, we'll define a Helm Chart resource pointing to the `stackdriver-metrics-adapter` chart.
4. **Deploy to OpenShift**: We'll assume that you have configured access to your OpenShift cluster where we will deploy the Helm chart.

Here's a comprehensive Pulumi TypeScript program that accomplishes this:

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

// The configuration for the 'stackdriver-metrics-adapter' Helm chart.
// Replace 'REPLACE_WITH_YOUR_OPENSHIFT_NAMESPACE' with your OpenShift namespace if necessary.
const stackdriverMetricsAdapterChart = new k8s.helm.v3.Chart('stackdriver-metrics-adapter', {
    // Specify your Helm chart repository here; 
    // for example, we're using a placeholder repository URL.
    // You need to replace 'http://your-chart-repo/' with the actual repository hosting this Helm chart.
    repo: 'http://your-chart-repo/',
    
    // The name of the chart we want to deploy
    chart: 'stackdriver-metrics-adapter',
    
    // Version of the Helm chart to deploy, adjust this as needed.
    version: 'REPLACE_WITH_DESIRED_CHART_VERSION',
    
    // Namespace where this chart will be deployed, this should be an existing namespace on your OpenShift cluster.
    namespace: 'REPLACE_WITH_YOUR_OPENSHIFT_NAMESPACE',
    
    // Values to configure `stackdriver-metrics-adapter`. 
    // You'll need to provide the relevant values that are needed for the chart.
    // Check the chart's `values.yaml` or documentation to find out what values are required.
    values: {
        // Example of value configuration:
        // googleServiceAccountKeyJson: 'REPLACE_WITH_YOUR_SERVICE_ACCOUNT_JSON',
        // External metrics API configuration, etc.
    },
    
    // Fetch options such as those related to TLS or authentication 
    // needed when OpenShift requires it to connect with the Helm chart repository.
    // Adjust these settings as per your OpenShift cluster's configuration.
    fetchOpts: {
        caFile: 'path-to-your-ca.cert',  // Add CA certificate file path if needed.
        // ... other fetch options
    },
    
    // Transformation, if needed, to modify the Kubernetes objects before they are created.
    // This can be useful to apply global configurations or policies.
    transformations: [
        (resource) => {
            // Example transformation: Add an annotation to every resource.
            if (!resource.metadata) {
                resource.metadata = {};
            }
            resource.metadata.annotations = {
                "pulumi.com/managed-by": "Pulumi"
            };
        },
    ],
});

// Export the base URL where the `stackdriver-metrics-adapter` can be accessed if available
export const stackdriverMetricsAdapterUrl = stackdriverMetricsAdapterChart.getResourceProperty(
    'v1/Service', 'stackdriver-metrics-adapter', 'status'
).apply(status => status.loadBalancer.ingress[0].ip || status.loadBalancer.ingress[0].hostname);
```

Before running the Pulumi program, ensure that you have the Pulumi CLI installed and that you're logged into the Pulumi service (or using an alternative state backend). Additionally, make sure you have `kubectl` configured to access your OpenShift cluster where you intend to deploy the Helm chart.

To run this Pulumi program:
1. Create a new directory for your Pulumi project.
2. Initialize a new Pulumi project using `pulumi new <template>` (you can use a Kubernetes TypeScript template).
3. Replace the content of `index.ts` with the code provided above.
4. Adjust the placeholder values in the code to match your specific Helm chart repository, chart version, and values.
5. Run `pulumi up` to preview and then deploy the resources to your OpenShift cluster.

The `transformations` property allows you to modify Kubernetes resources before they get created. In the example above, we are adding an annotation to every resource indicating that Pulumi manages it.

When working with Helm charts, it's essential to review `values.yaml` provided by the chart maintainer or its documentation to know which values you need to overwrite for the chart to be deployed correctly.

Moreover, it would be best if you considered any security and authentication requirements in your OpenShift environment while configuring Helm and Kubernetes provider credentials in Pulumi. These may involve adding CA certificates and other details to the `fetchOpts` configuration as needed for your specific Openshift cluster setup.