Using kubernetes policy.linkerd.io with k8s.keycloak.org

Question

Pulumi · Accepted Answer

To use policy.linkerd.io with Keycloak on Kubernetes, you would typically set up Keycloak as an Identity and Access Management (IAM) system and then use Linkerd to ensure secure communication between your services within the Kubernetes cluster. While Keycloak handles authentication and authorization, Linkerd provides a service mesh that can enforce policies and encrypt the traffic.

Below you'll find a Pulumi program written in TypeScript that demonstrates how you could define resources in a Kubernetes cluster to integrate Keycloak with Linkerd's policy engine. This program assumes you already have Linkerd and Keycloak installed in your Kubernetes cluster.

The program does the following:

1. Defines a NetworkPolicy that restricts traffic to the Keycloak service so that only pods with certain labels can communicate with Keycloak.
2. Sets up a PodSecurityPolicy for added security, which might be necessary depending on your cluster's requirements and the specifications of Keycloak and Linkerd.
3. Uses RBAC (Role-Based Access Control) to control access to resources within your Kubernetes cluster.

Please note that this is a high-level example. The actual implementation might require more specific configurations based on your cluster setup, the Keycloak deployment details, and Linkerd's setup.

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

// Create a new Kubernetes Network Policy that restricts traffic to Keycloak.
const keycloakNetworkPolicy = new k8s.networking.v1.NetworkPolicy("keycloak-network-policy", {
    metadata: {
        // The namespace should be where the Keycloak service is running.
        namespace: "keycloak-namespace",
    },
    spec: {
        // Apply the policy to the pods that match these labels.
        podSelector: {
            matchLabels: {
                app: "keycloak",
            },
        },
        policyTypes: ["Ingress"],
        ingress: [{
            // Define from which source pods the traffic is allowed.
            from: [{
                podSelector: {
                    // The labels depend on which pods should be allowed to communicate with Keycloak.
                    matchLabels: { "allowed-to-talk-to-keycloak": "true" },
                },
            }],
            // Allowing traffic on port 8080, which Keycloak uses.
            // Adjust the port number if Keycloak is configured to use a different port.
            ports: [{
                port: 8080,
                protocol: "TCP",
            }],
        }],
    },
});

// Create a PodSecurityPolicy for the Keycloak pods.
const keycloakPodSecurityPolicy = new k8s.policy.v1beta1.PodSecurityPolicy("keycloak-pod-security-policy", {
    metadata: { 
        // The name of the Pod Security Policy
        name: "keycloak-psp" 
    },
    spec: {
        // The policy settings - these should be configured according to your security requirements.
        privileged: false, // Don't allow privileged pods
        fsGroup: {
            rule: "RunAsAny",
        },
        runAsUser: {
            rule: "RunAsAny",
        },
        seLinux: {
            rule: "RunAsAny",
        },
        supplementalGroups: {
            rule: "RunAsAny",
        },
        volumes: ["configMap", "emptyDir", "projected", "secret", "downwardAPI", "persistentVolumeClaim"],
    },
});

// RBAC: Create a ClusterRole with policies related to Linkerd and Keycloak.
const linkerdKeycloakClusterRole = new k8s.rbac.v1.ClusterRole("linkerd-keycloak-clusterrole", {
    metadata: {
        name: "linkerd-keycloak-role",
    },
    rules: [
        {
            apiGroups: ["policy.linkerd.io"],
            // Depending on the permissions needed, you might need to scope down this rule.
            resources: ["*"],
            verbs: ["*"],
        },
        {
            apiGroups: ["k8s.keycloak.org"],
            resources: ["*"],
            verbs: ["*"],
        },
        // Add more rules for additional resources as necessary.
    ],
});

// Apply the resources to the cluster
export const networkPolicyName = keycloakNetworkPolicy.metadata.name;
export const podSecurityPolicyName = keycloakPodSecurityPolicy.metadata.name;
export const clusterRoleName = linkerdKeycloakClusterRole.metadata.name;
```

This Pulumi program sets the foundational resources for integrating Keycloak with the Linkerd policy engine in a Kubernetes cluster. When you run the program with the Pulumi CLI, these resources will be created in your Kubernetes cluster, provided you have configured your Pulumi for Kubernetes.

**Note**: Before applying this configuration please make sure you:

- Have Pulumi installed and configured for use with Kubernetes.
- Understand your organization's security policies and configure the roles, and policies accordingly.
- Have the `policy.linkerd.io` and `k8s.keycloak.org` CRDs installed on your cluster. This setup also assumes you have Linkerd and Keycloak installed and running.

Once these prerequisites are met, the Pulumi CLI can be used to deploy this configuration to your Kubernetes cluster. Make sure you review and adjust the policies according to your specific requirements and security practices.