This is a guest post written by Appranix.

Now that Red Hat OpenShift 4 has officially been released, it’s time to start thinking about migration from Red Hat OpenShift Container Platform 3 to OpenShift Container Platform 4.

You can check out the details about the differences between OpenShift 3 and 4 here.

One of the biggest differences between OpenShift 3 and 4 is how OpenShift 4 clusters operate using immutable and automated infrastructure enabled by RHEL CoreOS and automation. We're going to show you one way to migrate to this new platform with as few bumps as possible.

Use Red Hat Certified Appranix Platform to Migrate from OpenShift 3 to 4 Clusters

Appranix and Red Hat have worked closely together to provide a simpler migration path for OpenShift 3 cluster resources to OpenShift 4 using a service created on top of the Appranix Site Reliability Automation for Kubernetes.

Using Appranix (Red Hat Container Catalog), OpenShift 3 customers can back up and recover all the OpenShift 3 cluster resources to OpenShift 4 with a few clicks.

Advantages of Using Appranix for OpenShift 4 Migration

  • Simpler to get started with a SaaS-based migration solution. There is no infrastructure to set up. There is no configuration or separate management solution to set up for migration purposes.
  • Appranix migration solution is scalable so large cluster migration will be easier.
  • Complex OpenShift 3 cluster configurations are automatically captured and migrated over to OpenShift 4, simplifying operations.
  • Test your on-prem OpenShift 3 based applications on OpenShift 4 running on AWS.
  • Migrate your RBAC settings along with your cluster resources.
  • Migrate specific projects or all the projects together to the new OpenShift 4 clusters.
  • (optionally) With a product subscription, you can achieve multiple levels of resiliency for your container applications (see below for details).

Achieve Multiple Levels of OpenShift App Resiliency

Once you complete the OpenShift 3 to 4 migration, you can use Appranix to get Continuous App Resilience for your container applications running on OpenShift. Appranix offers multiple levels of application resilience, level 1 through 3 depending on your use case. Level-1 resilience offers a way to recover applications within the same region of a single cloud provider. This is useful for applications that need to rollback or recover from local region failures such as bad app deployments, or useful for situations where you need to have test environments quickly created within the same region but in another OpenShift cluster.

Level-2 resiliency is the capability of the applications to be brought up in another region of the same cloud provider. You could even keep your primary data infrastructure in the primary region but run your applications in another cluster in another region. This is useful for situations where a cloud region or zone failure or a cyber attack forces you to recover applications in another region. Level-3 resilience provides yet another layer of protection where you could recover applications across a different cloud provider.

How does Appranix SRA work?

To achieve multiple levels of resiliency for OpenShift applications, Appranix builds an application environment time machine automatically. With a single line of code in your DevOps pipeline, you can have improved application protection.

Cloud provider infrastructure services may fail for various reasons, besides being able to avoid cloud lock-in you can also achieve cross-cloud provider resiliency with a few clicks.

With Appranix, you can protect and recover entire applications for chaos engineering, disaster recovery, ransomware protection, and business continuity use cases. But the rest of this post will focus on how you can use Appranix to migrate from OpenShift 3 to 4.

How to Migrate OpenShift 3 to OpenShift 4 using Appranix Site Reliability Platform

Configure OpenShift 3 and 4 Clusters for Automated Discovery

Appranix assumes that customers have OpenShift 3 and 4 clusters running. If you have not created OpenShift 4 clusters, there is documentation from Red Hat on how to deploy OpenShift 4. You can configure your primary and target clusters in the same way in Appranix with a few steps.

Install Appranix Controller Agent for Discovering Clusters

Discovering cluster resources requires a small sidecar controller agent. Just copy and paste the curl command as shown below. Once the agent is installed on OpenShift 3 & 4, all the cluster resources, including namespaces, deployments, pods, services, and a host of other resources for the migration will be automatically discovered by Appranix.

Migrate Large Distributed Applications

This section shows how an example distributed microservices application called SockShop can be easily migrated from OpenShift 3 to 4. You can refer to the details of the SockShop and how it’s architected with microservices on GitHub. SockShop’s architecture is made up of multiple components as shown below.

Appranix discovers the resources, including, PoDs, deployments, services, and the cluster configurations necessary to protect and migrate to OpenShift 4.

OpenShift 3 running SockShop Application

Create Protection Policies for the Migration

Users can create flexible policies based on how they want to migrate. You can also have multiple baselines or a single hourly policy.

Migrate Multiple OpenShift 3 Clusters Using Protection Plans

Users can flexibly choose hourly or weekly or even monthly policy depending on application or namespace requirements to apply on OpenShift 3 clusters.

Appranix allows migration of all the namespaces in a cluster or specific namespaces to OpenShift 4.

Migrate to OpenShift 4 with a Single Click

Migration is simple with a single click recovery of the selected namespaces into the target OpenShift 4 cluster. Appranix takes care of the necessary work behind the scenes for the cluster configurations and resources to be appropriately captured and recovered into OpenShift 4.

Verify Migrated Applications on OpenShift 4

Login to your OpenShift 4 cluster and refresh projects to make sure all the applications and namespaces are proper. Repeat the same process for other namespaces by either creating new protection plans of modifying the existing protection plans.

Run Migrated Applications on OpenShift 4

Once your applications have been migrated using the Appranix recovery procedure, configuring your routes to point to the OpenShift 4 is key. It’s quite possible that you might want to do a test recovery before switching over from OpenShift 3 production environment. Once you have your OpenShift 4 running with a few applications in their respective namespaces, you might want to migrate more using the same process shown above.

Once you have migrated all the namespaces, you can protect your OpenShift 4 clusters for continued disaster recovery, ransomware protection, business continuity or future migration purposes. Appranix Site Reliability Automation can help provide a solution that is updated to keep up with OpenShift releases.

Summary

OpenShift 4 is a step forward with immutable architecture and the Operator framework model to automate complex configurations of applications and platforms running on the clusters. Appranix gives OpenShift customers a way to migrate to OpenShift 4 using its Site Reliability Platform for app-centric, cloud-native disaster recovery. You can use Appranix directly from the Red Hat Container Catalog.