Managing Multi-Tenant AI Services with Helm on Kubernetes

Question

Pulumi · Accepted Answer

Managing multi-tenant AI services on Kubernetes with Helm involves deploying and managing multiple instances of an application or service, each isolated from others within their own namespaces or using other Kubernetes constructs to achieve separation. Helm, the package manager for Kubernetes, helps package these services into charts, which define, install, and upgrade any Kubernetes application.

To manage multi-tenant services with Pulumi and Helm, you will use the Pulumi Kubernetes provider, which allows you to declare Kubernetes resources using the Pulumi infrastructure-as-code platform. Within this provider, there are specific classes to deploy Helm charts. A Helm chart can package all of the Kubernetes resources needed to run an application, dependency, or service.

Here's a simple Pulumi program in Python that demonstrates how to deploy a multi-tenant AI service using Helm on a Kubernetes cluster:

1. First, we'll create a Helm `Release`, which represents an instance of a chart running in a Kubernetes cluster. In the example, we'll assume that you have the Helm chart for the AI service available in a chart repository.
2. We use namespaces to ensure that each tenant's service is isolated.
3. Note that we pass a set of `values` to the Helm chart to configure each release. These values can be customized for each tenant.

Let's start with the Pulumi program:

```python
import pulumi
import pulumi_kubernetes as k8s

# Assume you're running this program with appropriate access to a
# configured Kubernetes cluster

# Define the Helm chart, its version, and the repository it can be found in
ai_service_chart = "ai-service-chart-name"
chart_version = "1.0.0"
repository = "http://my-chart-repo.example.com"

# Define the tenants, each with its own unique settings
tenants = [
    {"name": "tenant-a", "namespace": "tenant-a-ns", "cpuLimit": "500m", "memoryLimit": "1Gi"},
    {"name": "tenant-b", "namespace": "tenant-b-ns", "cpuLimit": "700m", "memoryLimit": "1.5Gi"},
    # Add more tenants as required...
]

# Loop over each tenant and create a Helm Release within their namespace
for tenant in tenants:
    # Create a Kubernetes Namespace for the tenant
    ns = k8s.core.v1.Namespace(
        tenant["name"],
        metadata={
            "name": tenant["namespace"]
        }
    )

# Deploy an instance of the chart for the tenant
    helm_release = k8s.helm.v3.Release(
        tenant["name"],
        args=k8s.helm.v3.ReleaseArgs(
            chart=ai_service_chart,
            version=chart_version,
            repository_opts=k8s.helm.v3.RepositoryOptsArgs(
                repo=repository
            ),
            namespace=ns.metadata["name"],
            values={
                "resources": {
                    "limits": {
                        "cpu": tenant["cpuLimit"],
                        "memory": tenant["memoryLimit"]
                    }
                }
            },
        ),
        opts=pulumi.ResourceOptions(depends_on=[ns])
    )

# Export the namespace and service URL for each tenant
    pulumi.export(f"{tenant['name']}_namespace", ns.metadata["name"])
    # Note: For the service URL, you would typically fetch the service endpoint from the Helm status
    # or set up an Ingress and export the ingress URL. This step is omitted for brevity.
```

In this program:

- We import the `pulumi` and `pulumi_kubernetes` packages to work with Pulumi and Kubernetes resources, respectively.
- We define the Helm chart details (`ai_service_chart`, `chart_version`, and `repository`).
- We specify a list of tenants in the `tenants` variable. Each tenant contains the configuration such as the name, namespace, CPU, and memory limits.
- For each tenant, we create a Kubernetes Namespace using the `k8s.core.v1.Namespace` class to ensure tenant isolation.
- We then deploy an instance of our AI service using the `k8s.helm.v3.Release` class to the tenant's namespace and configure it using the `values` parameter.
- We use `opts=pulumi.ResourceOptions(depends_on=[ns])` to ensure that the namespace is created before the Helm chart is deployed.
- Finally, we export the created namespace name to verify the deployment.

This program creates a Helm release for each tenant specified in the list of tenants. Each tenant is separated by their own Kubernetes namespaces, and the resources for each service can be configured individually.

It's important to note that this program assumes you have the appropriate Kubernetes context set in your Pulumi configuration and that you have access privileges to deploy to the cluster. Additionally, in a real-world scenario, you would obtain the service URL via the Helm release status or by setting up Ingress resources to expose your services securely.