Using kubernetes keyvaultflexvolume with gateway.envoyproxy.io

To integrate the Kubernetes Key Vault FlexVolume with Envoy Proxy (assuming you're looking to manage secrets like TLS certificates for Envoy), you'll want to use HashiCorp Vault as a secrets store alongside the Key Vault FlexVolume for Kubernetes. In this scenario, Pulumi doesn't directly interact with FlexVolume, but you can use Pulumi to manage the Kubernetes resources and the Vault configurations that provide secrets to your Envoy Proxy.

Before we dive into the Pulumi program, let me explain the general steps you'd follow:

1. Deploy an Envoy Proxy instance in your Kubernetes cluster.
2. Set up a Vault instance and configure a Kubernetes auth method within Vault so that pods can authenticate using their service account tokens.
3. Create a role within the Vault Kubernetes auth method that defines the permissions your Envoy Proxy will have.
4. Configure a Kubernetes Secret that uses the Key Vault FlexVolume driver to mount the Vault secrets into the Envoy proxy pod.

Here's a TypeScript program that outlines how you can accomplish tasks 2 and 3 with Pulumi. This setup assumes that you have the Vault agent and Key Vault FlexVolume driver set up and configured within your Kubernetes cluster.

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

// Initialize a Kubernetes provider using the default kubeconfig file location.
const k8sProvider = new kubernetes.Provider("k8s", {
  kubeconfig: "~/.kube/config",
});

// Step 1: Configuring Vault with Kubernetes Auth Method
const vaultKubernetesAuth = new vault.AuthBackend("k8sAuth", {
  type: "kubernetes",
});

// Vault's kubeconfig should include the token reviewer JWT and the Kubernetes CA cert
new vault.kubernetes.AuthBackendConfig("k8sAuthConfig", {
  backend: vaultKubernetesAuth.id,
  kubernetesHost: "https://kubernetes.default.svc", // Default cluster URL
  // Other required properties like your Token reviewer JWT and Kubernetes CA cert
}, { provider: vaultKubernetesAuth });

// Step 2: Setting up a SecretBackendRole specific to the needs of your Envoy Proxy
const secretBackendRole = new vault.kubernetes.AuthBackendRole("envoyProxyRole", {
  backend: vaultKubernetesAuth.id,
  roleName: "envoy-proxy",
  boundServiceAccountNames: ["envoy-sa"], // Replace this with your service account name
  boundServiceAccountNamespaces: ["default"], // Replace with your Envoy Proxy's namespace
  tokenPolicies: ["default"], // Replace with policies you have configured in Vault
}, { provider: vaultKubernetesAuth });

// Exporting the Vault role name
export const vaultRoleName = secretBackendRole.roleName;

In this program:

• A new Kubernetes auth backend is created in Vault, which will be used to authenticate requests from your Kubernetes cluster.
• The AuthBackendConfig configures the backend with the appropriate settings to enable communication and authentication with your cluster's API server.
• A new role called envoyProxyRole is set up for your Envoy Proxy to authenticate with Vault.

Please remember, this program just sets up the authentication method and a role in Vault, and it does not include the FlexVolume setup or an Envoy Proxy configuration. The setup of Envoy Proxy, the Key Vault FlexVolume driver, and the actual application of these Vault roles to Kubernetes resources/equivalence in FlexVolume should be done according to the documentation provided by your FlexVolume driver and Envoy's requirements.

This interaction assumes familiarity with Vault, Kubernetes secrets, and Envoy's configuration. Make sure you replace placeholders with your specific environment details. Each component (Vault, Key Vault FlexVolume, and Envoy Proxy) requires a significant amount of proper setup, which should be guided by the official documentation for each respective tool:

• Vault Kubernetes Auth Backend
• Vault Kubernetes Auth Backend Role
• Kubernetes Secret
• Envoy Proxy Documentation

This Pulumi program is the start of automating your cloud resource setup, specifically focusing on secrets management for your proxy. In practice, you'd have more components and configurations to manage based on your exact scenario and requirements.