Title: "Unlocking Synergy: RHACM Policies and ArgoCD Collaboration"
Introduction: In this blog post, we'll delve into the symbiotic relationship between Red Hat Advanced Cluster Management's (RHACM) policy framework and OpenShift GitOps, powered by Argo CD. RHACM is Red Hat's solution for Kubernetes MultiClusterManagement, with a strong emphasis on Governance, while Argo CD is a widely adopted GitOps engine that recently achieved CNCF graduated status.
Before we dive into the advantages, it's important to understand that RHACM's Governance Framework is a powerful tool on its own. For a comprehensive introduction to policies, please refer to our existing blogs here. Now, let's explore the synergies between RHACM Policies and ArgoCD.
RHACM Policies can be used to install and configure Argo CD consistently across Managing and Managed-Clusters. For instance, you can ensure that a specific Argo CD instance overwrites the default settings across all your namespaces and environments. This level of consistency is crucial for avoiding troubleshooting headaches down the line.
Example Policy:
kind: Policy
metadata:
name: example-policy
spec:
channel: stable
config:
env:
- name: DISABLE_DEFAULT_ARGOCD_INSTANCE
value: "true"
- name: ARGOCD_CLUSTER_CONFIG_NAMESPACES
value: <namespace to deploy to>
ArgoCD offers advanced templating features optimized for Multi-Cluster Management. This includes secrets management and dynamic configuration of resources like LimitRange and ResourceQuota. The benefit here is that you can customize specific elements of a policy across various clusters within your fleet, reducing duplication and simplifying maintenance.
Example Dynamic Configuration:
apiVersion: v1
kind: LimitRange
metadata:
name: mem-limit-range
namespace: '{{hub fromConfigMap "" "app-box-config" (printf "%s-namespace" .ManagedClusterName) hub}}'
# ... (other configurations)
RHACM's policy framework allows you to generate resources such as Roles and RoleBindings in one or multiple namespaces based on namespace names, labels, or expressions. This flexibility reduces the need for numerous individual policies when applying changes to specific namespaces.
Example Namespace Selection:
namespaceSelector:
matchLabels:
name: test2
matchExpressions:
key: name
operator: In
values: ["test1", "test2"]
You have the flexibility to merge or patch resources according to your requirements. Whether you need to make specific changes or enforce strict matching, you can configure policies accordingly.
Example Policy for Disabling Self-Provisioner Role:
kind: ClusterRoleBinding
apiVersion: rbac.authorization.k8s.io/v1
metadata:
name: self-provisioners
annotations:
rbac.authorization.kubernetes.io/autoupdate: 'false'
# ... (other configurations)
RHACM's Governance framework enables you to monitor resources instead of just creating or patching them. You can configure policies to inform you of the status of Kubernetes objects, helping you proactively identify issues.
Example Policy for Monitoring Terminating Namespaces:
spec:
remediationAction: inform
object-templates:
- complianceType: mustnothave
objectDefinition:
apiVersion: v1
kind: Namespace
status:
phase: Terminating
RHACM's Governance framework supports the creation of PolicySets, allowing you to group policies for more efficient management. These PolicySets can be configured using GitOps, providing both a UI and GitOps support.
Example PolicySet Configuration:
apiVersion: policy.open-cluster-management.io/v1beta1
kind: PolicySet
metadata:
name: certificates-policyset
namespace: cert-manager
spec:
description: "Grouping policies related to certificate handling"
policies:
- azure-clusterissuer-policy
- cert-manager-csv-policy
- certification-expiration-policy
You can configure how often policy checks are performed based on the current status of evaluated objects. This fine-grained control helps optimize resource consumption in environments with many policies.
Example Configuration for Evaluation Intervals:
spec:
evaluationInterval:
compliant: 10m
noncompliant: 10s
RHACM's PolicyGenerator offers seamless integration with ArgoCD. It can transform YAML resources into policies at runtime, providing more flexibility and customization options.
Example Usage of PolicyGenerator:
policies:
- name: policy-deployment
categories:
- System-Configuration
controls:
- ApplicationDeployment
manifests:
- path: input/
RHACM's Governance framework includes a Governance Dashboard that allows you to drill down into policy errors, providing valuable insights into compliance status.
Governance Dashboard Overview:
RHACM's Governance framework offers the flexibility of using Configuration Policies for fine-grained checks, allowing you to create individual policies for specific Kubernetes objects or bundle them together for streamlined management.
You can seamlessly integrate monitoring and Ansible automation into your policies. This enables automated governance and alerting, ensuring your clusters stay compliant.
RHACM Policies can check for expired certificates in different namespaces, providing valuable insights into security and compliance.
Example Certificate Policy:
apiVersion: policy.open-cluster-management.io/v1
kind: CertificatePolicy
metadata:
name: certificate-policy-1
namespace: kube-system
spec:
namespaceSelector:
matchLabels:
name: test2
matchExpressions:
key: name
operator: In
values: ["test1", "test2"]
minimumDuration: 100h
The synergy between RHACM Policies and ArgoCD is evident in the numerous advantages it offers. By combining the governance-focused capabilities of RHACM with the GitOps power of ArgoCD, you can achieve greater consistency, flexibility, and control in managing your Kubernetes clusters. This collaboration empowers you to maintain compliance, streamline operations, and ensure the reliability of your multi-cluster environments. Explore these capabilities, and unlock the true potential of Kubernetes cluster management with RHACM Policies and ArgoCD. Your feedback and insights on this integration are highly valuable to us as we continue to enhance these features.