Deploy the ceph helm chart on Google Kubernetes Engine (GKE)

Question

Pulumi · Accepted Answer

Deploying a Ceph cluster using Helm on Google Kubernetes Engine (GKE) involves several steps. First, we'll set up a GKE cluster, then we'll install Helm in our environment, followed by deploying Ceph via a Helm chart. For simplicity, I'll assume that you have `gcloud`, `kubectl`, `helm`, and `pulumi` command-line tools installed and configured for use. I'll guide you through the process and the Pulumi program required to accomplish it.

### Creating a GKE Cluster with Pulumi

Before deploying Ceph, we need to have a GKE cluster. Here's how you can do it with Pulumi:

1. **Define the GKE Cluster:** We will define the configuration for our GKE cluster, including the number of nodes, their type, and the Kubernetes version.

2. **Initialize the Cluster:** After defining the cluster, Pulumi will take care of initializing it and setting up the required resources within Google Cloud.

### Installing Helm and Deploying Ceph

With our GKE cluster in place, we will move on to setting up Helm:

1. **Install Helm Client:** Ensure that Helm is installed on your machine and configured to interact with the Kubernetes cluster.

2. **Add Ceph Helm Repository:** Helm repositories contain the charts that describe the installation and configuration details of Kubernetes applications.

3. **Install Ceph Chart:** Execute the command to install the Ceph chart on your cluster using Helm.

### Pulumi Program to Create a GKE Cluster

This Pulumi TypeScript program will create a GKE cluster suitable for our Ceph Helm Chart deployment:

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

// Create a GKE cluster
const cluster = new gcp.container.Cluster("ceph-cluster", {
    initialNodeCount: 3,
    minMasterVersion: "latest",
    nodeVersion: "latest",
    nodeConfig: {
        machineType: "n1-standard-2", // Choosing a standard machine type. Adapt as per your needs.
        oauthScopes: [
            "https://www.googleapis.com/auth/compute",
            "https://www.googleapis.com/auth/devstorage.read_only",
            "https://www.googleapis.com/auth/logging.write",
            "https://www.googleapis.com/auth/monitoring"
        ],
    },
});

// Export the Cluster name and Kubeconfig
export const clusterName = cluster.name;
export const kubeconfig = cluster.endpoint.apply(endpoint => {
    const context = `${gcp.config.project}_${gcp.config.zone}_${clusterName}`;
    return `apiVersion: v1
clusters:
- cluster:
    certificate-authority-data: ${cluster.masterAuth.clusterCaCertificate}
    server: https://${endpoint}
  name: ${context}
contexts:
- context:
    cluster: ${context}
    user: ${context}
  name: ${context}
current-context: ${context}
kind: Config
preferences: {}
users:
- name: ${context}
  user:
    auth-provider:
      config:
        cmd-args: config config-helper --format=json
        cmd-path: gcloud
        expiry-key: '{.credential.token_expiry}'
        token-key: '{.credential.access_token}'
      name: gcp
`;
});

// Initialize Kubernetes provider
const k8sProvider = new k8s.Provider("gke-k8s", {
    kubeconfig: kubeconfig,
});
```

This program will initialize the GKE cluster with the specified configuration. Once the cluster is created, you will get a `kubeconfig` file that allows you to interact with the cluster via `kubectl`.

### Next Steps for Helm and Ceph

After setting up the cluster with Pulumi, you would proceed with these steps:

1. **Initialize Helm Client:**
   - Run `helm init` to set up the Helm client on your machine.
   
2. **Add the Ceph Helm Chart Repo:**
   - Add the repository that contains the Ceph chart: `helm repo add ceph https://ceph.github.io/helm-charts`.

3. **Install the Ceph Chart:**
   - Install the chart: `helm install --name my-ceph-cluster ceph/ceph`.

Remember that deploying a storage system like Ceph requires careful planning and consideration of your workload needs. It involves stateful data handling, which is critical. The above steps give you a starting point, and further configuration of the Ceph cluster to cater to specific use cases will be needed.

Keep in mind to replace `my-ceph-cluster` with your desired release name, and you may need to provide additional configuration parameters as per the Ceph Helm chart's documentation. Ensure every prerequisite is met for the Ceph Helm chart.

Lastly, if you encounter any issues or need to understand how some specific settings work within the context of Google Cloud, Helm, or the chosen Helm chart for Ceph, you should consult the respective documentation or support forums for guidance.