Using kubernetes security.istio.io with secrets.hashicorp.com

Question

Pulumi · Accepted Answer

To integrate Istio within a Kubernetes cluster with HashiCorp Vault (referred to with the domain secrets.hashicorp.com in your request), we will use Pulumi providers for both Kubernetes and HashiCorp Vault. Istio is a service mesh that provides features like traffic management, security, and observability to microservices. One of its security features includes managing secrets for service-to-service communication within the mesh.

HashiCorp Vault is a tool for secrets management that allows you to securely store and tightly control access to tokens, passwords, certificates, API keys, and other secrets.

Here's a high-level overview of what we need to do:

Set up a Kubernetes cluster that can run Istio (this example assumes the cluster is already up and running).
Install Istio on the Kubernetes cluster.
Set up HashiCorp Vault with a Kubernetes secret backend to store secrets.
Create a Kubernetes secret to hold the Vault token or other authentication means so Istio can retrieve its secrets from Vault.

We'll use the vault and kubernetes Pulumi providers. The Vault provider allows us to interact with a Vault server, and the Kubernetes provider allows us to define the Kubernetes resources like the Secret in which we'll store some Vault-specific configurations.

Here's how you might begin setting this up using Pulumi with TypeScript:

import * as k8s from "@pulumi/kubernetes";
import * as vault from "@pulumi/vault";

// Configure the Kubernetes provider using the current context in your kubeconfig.
const k8sProvider = new k8s.Provider("k8s", {
    kubeconfig: "<Your KUBECONFIG content here>",
});

// Create a Kubernetes secret backend in HashiCorp Vault.
const secretBackend = new vault.kubernetes.SecretBackend("my-secret-backend", {
    path: "kubernetes/",
    // Specify other properties as required for your use case.
}, { provider: vaultProvider });

// Kubernetes Secret to hold the Vault token - you will normally get that token from environment variables or Pulumi config.
const vaultTokenSecret = new k8s.core.v1.Secret("vault-token", {
    metadata: {
        name: "vault-token",
    },
    stringData: {
        // This token should be the one with the required permissions in Vault
        // Never hardcode tokens; it's done here merely as an illustrative example.
        token: "<VAULT_TOKEN_HERE>",
    },
}, { provider: k8sProvider });

// Create a Vault role allowing Istio to authenticate using Kubernetes service accounts and retrieve secrets.
const vaultAuthRole = new vault.kubernetes.SecretBackendRole("istio-auth-role", {
    backend: secretBackend.path,
    name: "istio-auth",
    allowedKubernetesNamespaces: ["*"],
    kubernetesRoleName: "istio",
    // Configure role with the correct policies.
}, { provider: vaultProvider });

// Now Istio can be set up on the Kubernetes cluster with its control plane components configured to fetch secrets from Vault.
// However, this action typically would require custom installation of Istio and bootstrapping Vault with specific configurations
// which are beyond the scope of what can be easily defined in a Pulumi program.

// Important notes:
// - Istio's deployment configuration will need to point to the correct Vault Kubernetes role and service account.
// - Depending on the access policy configurations in Vault, the service account might need additional permissions.

// Be sure to replace placeholder tokens and configuration details with 
// real-world values obtained from your Kubernetes cluster and Vault server configurations.

// More information can be found in the Pulumi documentation:
// - Vault provider: https://www.pulumi.com/registry/packages/vault/
// - Kubernetes provider: https://www.pulumi.com/registry/packages/kubernetes/

In the code above:

First, we assume there's an existing Kubernetes cluster running, and your kubeconfig provides the necessary credentials.
We create a backend for Kubernetes secrets in Vault, which will be used to configure where and how vault stores the Kubernetes-associated secrets.
A Kubernetes secret is used to store the Vault token. Note that in a real-world setup, you'd fetch the token securely from your environment or a secrets manager, not hardcode it as shown here.
We define a Vault role for Kubernetes authentication. Istio will assume this role when interacting with Vault to fetch secrets.
Finally, while the actual injection of Vault secrets into Istio and the installation of Istio are outside the scope of this example, we provide placeholders where additional configuration and installation steps would occur.

Remember to replace <Your KUBECONFIG content here> and <VAULT_TOKEN_HERE> with the actual kubeconfig and Vault token, respectively. The way Istio integrates with Vault for its secrets will require additional configuration, typically done when installing Istio.

For a deeper dive into using Pulumi with Kubernetes and integrating with other cloud services, you might want to look at the Pulumi documentation and tutorials which can guide you through various scenarios and patterns:

Kubernetes: Pulumi Kubernetes Documentation
Vault: Pulumi Vault Documentation

For more information on working with Istio and its security practices, you should refer to the official Istio documentation:

Istio: Istio Security Documentation