/HCP-Gitops

HCP-Gitops

This repository outlines the steps for provisioning a hosted control plane using GitOps principles.

Prerequisites

You must meet the following prerequisites to create an OpenShift Container Platform cluster on OpenShift Virtualization:

  • You need administrator access to an OpenShift Container Platform cluster, version 4.14 or later, specified by the KUBECONFIG environment variable.

  • The OpenShift Container Platform hosting cluster must have wildcard DNS routes enabled, as shown in the following DNS:

    oc patch ingresscontroller -n openshift-ingress-operator default --type=json -p '[{ "op": "add", "path": "/spec/routeAdmission", 
"value": {wildcardPolicy: "WildcardsAllowed"}}'

  • The OpenShift Container Platform hosting cluster must have OpenShift Virtualization, version 4.14 or later, installed on it.

  • The OpenShift Container Platform hosting cluster must be configured with OVNKubernetes as the default pod network CNI.

  • The OpenShift Container Platform hosting cluster must have a default storage class. For more information, see Postinstallation storage configuration. The following example shows how to set a default storage class:

    oc patch storageclass ocs-storagecluster-ceph-rbd -p '{"metadata": {"annotations":{"storageclass.kubernetes.io/is-default- 
class":"true"}}}'

  • You need a valid pull secret file for the quay.io/openshift-release-dev repository.

  • Before you can provision your cluster, you need to configure a load balancer. For more information, see Configuring MetalLB.

  • For optimal network performance, use a network maximum transmission unit (MTU) of 9000 or greater on the OpenShift Container Platform cluster that hosts the KubeVirt virtual machines. If you use a lower MTU setting, network latency and the throughput of the hosted pods are affected. Enable multiqueue on node pools only when the MTU is 9000 or greater.

  • The multicluster engine operator must have at least one managed OpenShift Container Platform cluster. The local-cluster is automatically imported in multicluster engine operator 2.4 and later. See Advanced configuration for more information about the local-cluster. You can check the status of your hub cluster by running the following command:

    oc get managedclusters local-cluster

Configure ArgoCD

Prerequisites

Prerequisites

  • A running Argo CD deployment
  • Access to the Git repository containing your application manifests (HTTPS URL or SSH details)
  • Authentication credentials for the Git repository (if required)

Adding a Repository using Argo CD UI

  1. Access Argo CD UI: Open your Argo CD dashboard in your web browser.

  2. Navigate to Settings: Click on the Settings option in the left-hand navigation menu.

  3. Manage Repositories: Under Settings, select Repositories.

  4. Connect a New Repository: Click the Connect Repo Using... button. Choose the appropriate connection method based on your Git repository (SSH, HTTPS, or GitHub App).

  5. Fill in Repository Details:

    • Type: Select git.

    • Name: Provide a unique name to identify this repository within Argo CD.

    • Repository URL: Enter the URL of your Git repository (e.g., HTTPS URL or SSH URI).

    • Credentials (if private): For private repositories, enter the username and password (HTTPS) or configure SSH key access.

    • Username: Username for your Git repository account (if required).

    • Password: Password for your Git repository account (if required).

    • SSH Private Key: You can upload your private key file directly in the UI (not recommended for production due to security concerns).

  6. Save the Configuration: Click the Create button to establish the connection with your Git repository.

Creating an Argo CD Application

  1. Access Argo CD UI: Open your Argo CD dashboard in your web browser.

  2. Navigate to Applications: Click on the Applications tab in the left-hand navigation menu.

  3. Create a New Application: Click the Create Application button.

  4. Application Details:

    • Name: Provide a unique name for your application.
    • Project: Select the project where you want to deploy the application (optional, can be created during application creation).
    • Sync Policy: Choose the desired synchronization behavior (Automated, Manual, or Hook).

  5. Source Details:

    • Git Repository: Select the previously connected Git repository from the dropdown menu.
    • Path: Specify the path within your Git repository that points to the deployment manifest file(s) for this application. In our case it is "."

  6. Destination Details:

    • Cluster: Choose the Kubernetes cluster where you want to deploy the application resources.

  7. Leave the other fields blank and click the Create button to create the Argo CD application.

Helm Chart Structure:

The Helm chart follows the standard structure:

  • Chart.yaml: Contains the HCP chart definition files.
  • templates: Contains the template files used for generating deployment manifests.
  • values.yaml: The default configuration values for the HCP cluster.

Using the Helm Chart

  1. Review values.yaml: The values.yaml file defines the default configuration for your HCP cluster. Carefully review the options and modify them according to your specific requirements. This file controls aspects like worker_count, CPU, Memory, and more.

  2. To customize the HCP cluster provisioning process, modify the following:

    • values.yaml: This is the primary file for overriding default settings. Adjust any configuration options as needed.
    • templates: For advanced customization, you can modify the template files within the templates directory.