Using kubernetes cluster with postgres-operator.crunchydata.com

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Pulumi · Accepted Answer

To deploy a Kubernetes cluster and use it with `postgres-operator.crunchydata.com`, you would typically accomplish this in a few steps:

1. **Provision a Kubernetes cluster**: Use Pulumi to provision a Kubernetes cluster on your cloud provider of choice (e.g., AWS, Azure, GCP, DigitalOcean, etc.). This involves creating instances that will run as your cluster nodes and setting up the Kubernetes control plane.

2. **Configure kubectl**: Once the cluster is provisioned, you need to configure `kubectl` – the Kubernetes command-line tool – to communicate with your new cluster. This usually involves retrieving the kubeconfig file from your cloud provider.

3. **Install the Postgres Operator**: With `kubectl` configured, you can then use Pulumi to install the Crunchy Data Postgres Operator on your Kubernetes cluster. This operator will manage Postgres instances in your cluster.

Below is a complete TypeScript program that demonstrates how to set up a Kubernetes cluster and deploy the Crunchy Data Postgres Operator to it:

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

// Step 1: Provision a Kubernetes cluster.
// In this example, we'll use Amazon EKS for our Kubernetes cluster.

// Create an EKS cluster
const cluster = new aws.eks.Cluster("my-cluster", {
    roleArn: /* Your EKS Cluster Role ARN */
    vpcConfig: {
        // Your VPC configuration goes here
    },
    // More configuration, if necessary
});

// Export the cluster's kubeconfig
export const kubeconfig = cluster.kubeconfig;

// Step 2: Configure kubectl using the exported kubeconfig from the EKS cluster.
// You will typically do this step outside of Pulumi, using the `export` command.
// For example, in your terminal, you might run:
// `pulumi stack output kubeconfig > kubeconfig.json`
// `export KUBECONFIG=$(pwd)/kubeconfig.json`

// Step 3: Install the Crunchy Data Postgres Operator on your Kubernetes cluster.

// Create a k8s provider instance using the kubeconfig from the EKS cluster
const provider = new k8s.Provider("k8s-provider", {
    kubeconfig: kubeconfig,
});

// Use a YAML manifest or Helm chart to deploy the Postgres operator
const operatorUrl = "https://operatorhub.io/install/postgres-operator.yaml"

const postgresOperator = new k8s.yaml.ConfigFile("postgres-operator", {
    file: operatorUrl,
}, { provider: provider });

// Now your EKS cluster is running, and it has the Crunchy Data Postgres Operator installed on it.
// You can use Pulumi to create and manage your Postgres instances using the operator.

// Don't forget to replace placeholders like role ARN and VPC config with actual values from your AWS account.
```

Let’s break this down:

- We start by importing the required Pulumi modules.
- In this code snippet, we are using Amazon Web Services (AWS) to provision an Elastic Kubernetes Service (EKS) cluster. You would need to provide the appropriate role `ARN` and `VPC` configuration specific to your AWS account.
- For the Kubernetes cluster, we are using the `aws.eks.Cluster` resource, which lets us describe the desired state of our EKS cluster within our Pulumi program. Replace the placeholders with actual values from your AWS account setup.
- Once the cluster is created, we export the `kubeconfig`. This file contains the necessary configuration to connect to your Kubernetes cluster with `kubectl` or other Kubernetes management tools.
- Next, we set up a new `k8s.Provider` instance, which allows us to interact with the cluster using the Pulumi Kubernetes provider. We need to pass in the `kubeconfig` we obtained earlier.
- We then use Pulumi’s ability to apply YAML manifests directly to our cluster to install the Crunchy Data Postgres Operator. For this, a URL to the operator's YAML manifest is used. Make sure that the URL points to the latest and correct operator manifest file. You can find the link to the latest version on the [official operator page](https://github.com/CrunchyData/postgres-operator).

Please replace placeholder values and comments (`/* ... */`) with your actual configuration details. To execute this program, you would need to set up Pulumi on your machine, configure AWS credentials, and run `pulumi up`. Always ensure you check the details for the latest versions and configurations on the respective documentation pages for [AWS EKS](https://www.pulumi.com/docs/reference/pkg/aws/eks/cluster/) and [Crunchy Data Postgres Operator](https://access.crunchydata.com/documentation/postgres-operator/latest/).