You finally convinced the powers that be to migrate to Kubernetes. Way to go! But now the real work begins. As the team responsible for the Kubernetes platform, you need to plan and execute a successful migration. No pressure!

Don’t let the complexity intimidate you. With some strategic planning and the right guidance, you can make this transition as smooth as possible. This article will outline some key considerations and best practices to help you migrate existing workloads and build new services in Kubernetes. You’ll learn how to assess readiness, choose the right migration strategy, handle persistent storage, and optimize your cluster for performance and cost. We’ll also provide tips to help you avoid common pitfalls and speed up your developer onboarding. Whether you’re migrating from virtual machines (VMs), cloud services, or bare metal, we’ve got you covered. Let’s break this down step-by-step so you can stick the Kubernetes landing!

Why Migrate to Kubernetes?

If you’re managing infrastructures and applications, Kubernetes can make your life a whole lot easier. Here are a few of the major benefits of migrating to Kubernetes:

Reduce Management Overhead

Kubernetes automates the deployment, scaling, and management of containerized applications. This means you can stop worrying about manually configuring and connecting resources because Kubernetes does the work for you so you can focus on higher-value tasks.

Improve Resiliency

Kubernetes ensures your applications are always running by restarting containers that fail and redistributing your workloads when nodes go down. This high availability means you can sleep better at night knowing your services will be there when your users need them.

Enable Faster Development

Kubernetes accelerates development workflows by making it easy to package, deploy, and scale applications. Developers can get their code from dev all the way to production in a fast, repeatable way, which  allows teams to focus on innovation rather than infrastructure wrangling.

Gain Portability

Kubernetes works across on-premises data centers and public clouds like AWS, Microsoft Azure, and Google Cloud. This means you can move workloads between environments or burst into the cloud to meet increased demand. This portability helps avoid lock-ins and gives you flexibility in where and how you run your applications.

Migrating to Kubernetes does require some investment, but the benefits to your platform team and organization can be huge. With Kubernetes managing your infrastructure, you’ll gain agility, reliability, and portability so you can build better software faster. The future of application development is containerized, and Kubernetes puts you at the cutting edge.

Key Considerations When Migrating to Kubernetes

So, your team has decided to make the move to Kubernetes. Congratulations! This transition will provide huge benefits, but migrating from a traditional data center setup or other infrastructure platform to Kubernetes requires some planning. Here are some steps you should take when starting your migration to Kubernetes:

Application Architecture

First, evaluate how compatible your apps are with containers and microservices. Monolithic apps may need to be redesigned, so make a plan for how components will interact with each other in a distributed system.

Infrastructure Requirements

Next, determine what Kubernetes infrastructure you need. How many nodes? What instance types? Do you need a managed Kubernetes service like GKE or EKS? Make sure you understand storage, networking, and other requirements.

Backup and Disaster Recovery

With any migration, having a solid backup and disaster recovery (DR) plan is critical. Look for a solution that’s designed specifically for Kubernetes like Kasten K10, which will allow you to back up and restore applications, databases, and the Kubernetes control plane. Fast recovery is key to avoiding downtime!

Security

Security is essential, so define your policies for pod security, network policies, Role-based Access Control (RBAC), and auditing before migration. Use tools like Twistlock, Aqua, or Neuvector to scan images and enforce policies.

Team Skills

Finally, ensure your team has the necessary skills they need to manage Kubernetes. They’ll also need to be comfortable with containers, microservices, and troubleshooting distributed systems, so provide training on Kubernetes fundamentals and how to operate your specific installation.

With the right planning and preparation, migrating to Kubernetes can be a smooth transition. Following these key considerations will set your team up for success as you embark on your Kubernetes journey!

Choosing the Right Kubernetes Migration Strategy

With Kubernetes, there are a few ways to migrate your workloads, and the strategy you choose depends on your priorities and constraints. Here are some possible routes to take and the pros and cons that come with each option.

Replatforming

This involves taking your existing VMs or containers and deploying them on Kubernetes with minimal changes. It’s the fastest way to get up and running on Kubernetes, but you won’t be able to realize many of the benefits of Kubernetes. You’ll still be managing your infrastructure and your workloads likely won’t be optimized to take advantage of Kubernetes’ scalability and resilience.

Refactoring

For a more transformative migration, refactor your applications to become cloud native. This means breaking down monolithic apps into microservices, making them horizontally scalable, and building in resilience, and Kubernetes’ architecture aligns well with these principles. Refactoring does require significant investment to rearchitect your apps, but the long-term benefits are huge. Your apps will be more robust, scalable, and portable across clouds.

Rearchitecting

The most ambitious approach is to re-architect your infrastructure and applications from the ground up to accomidate Kubernetes. This means you’ll design everything around Kubernetes’ capabilities and best practices. This is really only feasible if you’re building new applications or undergoing a major systems overhaul. While rearchitecting requires the most effort up front, you end up with a system that’s optimized for Kubernetes and can evolve as your needs change.

For most teams, re-platforming parts of your system while refactoring other workloads over time is a practical strategy. You can get experience with Kubernetes while upgrading apps one by one, so don’t feel like you have to rearchitect everything right out of the gate. With planning, you can ensure a smooth migration to Kubernetes that moves at your own pace.

Migrating Stateful Applications to Kubernetes

Migrating stateful apps like databases to Kubernetes requires some extra attention. These apps maintain data that must persist, even if containers restart or move to different nodes. As a platform team, you’ll need to carefully plan how to migrate this critical data.

Persistent Storage

First, determine how you’ll provide persistent storage for your stateful apps’ data. Kubernetes supports many storage options, ranging from network storage to cloud provider storage. Choose a storage class that meets your needs for performance, scalability, and durability.

Data Snapshots

Before migrating a stateful app, snapshot its data so you have a backup. This gives you a restore point in case anything goes wrong during migration. Use a tool like Kasten K10 to automatically snapshot your apps’ data according to a schedule you define.

Deploy the App

Deploy your stateful app to Kubernetes by following best practices. This includes:

• Using a StatefulSet for deployment
• Mapping your persistent storage to the StatefulSet
• Exposing the app through a Kubernetes Service
• Configuring pods to use persistent storage for app data

Test and Restore (if Needed)

Once deployed, thoroughly test your stateful app to ensure it’s working properly in Kubernetes and that data persists as expected. If issues arise, you can restore the app from your pre-migration snapshot using Kasten K10. This allows you to quickly revert and redeploy without data loss.

Migrating stateful applications requires caution, but with the right preparation and tools, platform teams can successfully transition these critical apps to Kubernetes. Following these best practices will help ensure your stateful apps and data thrive in their new environment.

Ensuring Application Availability During Migration

Migrating to Kubernetes is not without risk. As a platform team, ensuring your applications stay up and running during the transition is the top priority. Here’s some key things to keep in mind:

Choose a Phased Approach

Don’t try to migrate all your applications at once; take it slow and choose a phased rollout plan. Start with a few non-critical applications first to test the process and once you’ve worked out any kinks, move on to more important ones. This minimizes disruption and allows you to learn as you go.

Set up a Sandbox Environment

Build a sandbox Kubernetes environment that mimics your production setup. Then deploy copies of your applications here first to uncover any issues, then make necessary changes before promoting your apps to production. This also gives developers time to get familiar with Kubernetes without impacting live apps.

Have a Rollback Plan

Even with testing, problems can still emerge. Establish a clear plan for rolling back applications to your legacy environment in case of errors or downtime. Practice this plan ahead of time so you can act quickly if needed. Tools like Velero or Kasten K10 can help automate application backup and restoration across your environments.

Add Capacity and Redundancy

For critical apps, add extra capacity and redundancy in your Kubernetes cluster before migration. This can include running multiple instances of an app, using replica sets, deploying across zones, and more. This helps ensure maximum availability even under increased load or system failure. Remove excess capacity once your migration is complete and your applications have stabilized.

Monitor Closely

Closely monitor your applications for signs of trouble both during and after migration and track metrics like CPU usage, memory usage, network traffic, and application uptime/downtime. Many monitoring tools can integrate with Kubernetes to give you visibility into the health of your clusters, nodes, pods, and applications. Address any issues immediately to avoid disruption.

With the proper planning and safeguards in place, migrating your applications to Kubernetes can be a smooth process. But staying vigilant and taking things slow is key to minimizing risks and keeping your apps up without a hitch.

Securing Your Kubernetes Environment

RBAC

To control who has access to your Kubernetes API and resources, use RBAC, which lets you grant specific permissions to users or groups. For example, you may want developers to have read/write access to pods, but only read access to secrets. RBAC makes it easy to set these types of granular permissions.

Network Policies

By default, pods in Kubernetes can connect to any other pods. To limit which pods can communicate with each other, implement network policies. For example, you may want to block all ingress (i.e., incoming) traffic to pods, except specific IP ranges. Or you may only want to allow certain pods to access a database pod. Network policies give you greater control over pod networking.

Container Security

It’s important to scan your container images for vulnerabilities before deploying them. Use a tool like Docker Security Scanning or Trivy to scan images for known issues. You should also follow best practices for container building, like:

• Running containers as non-root users
• Not installing unnecessary packages
• Keeping container images up to date with the latest patches

Secret Management

Don’t store sensitive data like passwords, API keys, or SSH keys directly in your Kubernetes manifests or source code. Use a secret management tool like HashiCorp Vault to encrypt and securely store your secrets. You can then mount secrets into your pods at runtime without exposing your raw secret data.

Auditing

Enable auditing on your Kubernetes API server to log all requests and record details like who made the request, the resource that was accessed, and the response. Auditing gives you visibility into how the API is being used and can alert you to potential malicious activity. Review audit logs regularly to detect security issues early.

Migrating to Kubernetes introduces some new security considerations, but with tools like RBAC, network policies, and secret management, you can lock down your cluster and sleep soundly at night. Review security best practices and enable auditing to stay on top of any issues — your platform team will thank you!

Backup and DR for Kubernetes

Backing up your Kubernetes cluster and ensuring DR is crucial. As a platform team, you’ll want to make sure your organization’s Kubernetes infrastructure and applications are protected in case of unexpected events.

Backup Kubernetes Components

To back up Kubernetes, focus on etcd, the API server, and PersistentVolumes. Etcd is the key-value store that contains cluster data, so back that up daily. Also back up the API server, which handles API requests and persists data to etcd. Finally, back up any PersistentVolumes used by your applications. These steps will allow you to restore Kubernetes to its last known good configuration.

Application Data

Your applications likely have databases, file shares, and other data that resides outside Kubernetes. Have a strategy to back those up as well, daily if possible. If disaster strikes, you’ll want to be able to restore application data in addition to your Kubernetes infrastructure.

DR plan

Create a DR plan for various scenarios. If your entire cluster goes down, have a plan to redeploy it to another cloud or datacenter. If only certain nodes are lost, know how to recover just those nodes. Regularly test and practice your DR procedures to avoid surprises during an actual event.

Consider a Managed Backup Solution

Backing up Kubernetes and all related components can be complex. Consider using a managed backup and DR solution for Kubernetes. These services can automatically back up etcd, the API server, PersistentVolumes, and application data. They also should provide restore functionality in case you need to recover from a disaster. Leveraging a managed service can save your platform team time and ensure your backups are done properly.

Migrating to Kubernetes provides powerful infrastructure automation, but also brings new responsibilities. By making Kubernetes backup and DR a priority, your platform team will give your organization confidence in this new technology. With a solid strategy and possibly a managed solution in place, you’ll be well on your way to Kubernetes success!

Monitoring and Troubleshooting Your Kubernetes Migration

Your Kubernetes migration is complete, but your work isn’t over quite yet. Now is the time to keep a close eye on how your applications and infrastructure are performing to ensure there are no issues. As the platform team, you’ll want to establish monitoring to track key metrics and set up alerts for potential problems.

Start by monitoring cluster health and capacity and watch for signs that your cluster is overloaded or resources are constrained. Also check your API server health, node health, pod health, and network connectivity, then set up alerts for spikes in CPU/memory usage, increased latency, or dropped requests.

Also pay attention to application performance and availability. Track metrics like request rates, error rates, latency, and uptime and set thresholds to alert you if an app’s performance degrades or goes down. Check that all your apps have been deployed as expected and are functioning properly in your new environment.

Monitor your Kubernetes components and services. Make sure the API server, scheduler, controller manager, kubelet, and kube-proxy are all operating as intended. Watch for warning or error logs from these components and address any issues right away.

Once monitoring is in place, you’ll need to troubleshoot any problems that come up. Check Kubernetes and application logs for error messages to diagnose issues. You can also use Kubernetes tools like kubectl  to get more details on specific resources. For complex issues, you may need to SSH into nodes or view Kubernetes event logs.

Don’t forget your backing services either! Monitor your network, storage, load balancers, and any hosted databases or caches. Issues with these supporting systems can also impact your Kubernetes clusters and apps.

Staying on top of monitoring and troubleshooting will help ensure your Kubernetes migration is successful in both the short and long term. Be diligent, respond quickly to alerts, and address any issues to keep your new platform running smoothly.

Kubernetes Migration FAQsMigrating to Kubernetes is a big step, and you probably have a lot of questions. Here are some of the FAQs we get from platform teams who are going through a Kubernetes migration.

How long will the migration take? The timeline will depend on the size and complexity of your current infrastructure. For a small setup with a few apps, the migration could take just a few months, but larger, more complex environments with many legacy apps may need 6 – 12 months. The key is starting with a well-defined plan and phasing the work out.

Do we need to rearchitect our apps? Not necessarily. While Kubernetes works best with cloud-native apps designed for containers and microservices, you can still migrate many monolithic apps. You’ll want to evaluate each app to determine how much re-engineering is needed. Some may only require minor changes, while others may need significant refactoring to become cloud ready.

How will this impact app teams? The impact on app teams will depend on how much change is needed. Teams responsible for apps that can migrate with little or no re-engineering may notice minimal disruption. Teams with apps that require significant rearchitecting will need to invest more time, but the long-term benefits of migrating to Kubernetes can make it worthwhile. With proper planning and communication, you can minimize disruption.

What happens to our existing infrastructure? Your existing infrastructure components like VMs, storage volumes, and networks will need to transition to Kubernetes infrastructure components like nodes, persistent volumes, and networking. Work with your cloud or infrastructure team to develop a plan for how to best map your current resources to their Kubernetes equivalents and decommission legacy infrastructure that you no longer need.

How do we secure Kubernetes? Kubernetes introduces some new security concerns, but also has many built-in security features. Focus on strategies like RBAC policies, network policies, admission controllers, pod security policies, and integrating with the enterprise security tools you already use. Lock down the Kubernetes API server and use tools like Kasten K10 to secure Kubernetes workloads. With good DevSecOps practices, Kubernetes can be deployed securely.

Migrating to Kubernetes is a big investment, but by addressing concerns upfront and with the right planning and partnerships, platform teams can feel confident in making the move to Kubernetes. The benefits of improved scalability, agility, and reliability will make the journey worthwhile.

Conclusion

So, there you have it. Migrating to Kubernetes is no small task, but with the right planning and preparation, your platform team can make it happen. Focus on getting stakeholder buy-in, choosing the right migration strategy, and investing in training and don’t forget to think about backup and DR from the start. Kubernetes offers a lot of advantages, but you need to architect it properly at the outset. Approach migration in phases, learn from your early wins and losses, and continue optimizing over time. Most importantly, make sure your team is along for the ride. With their expertise and enthusiasm, you can build a Kubernetes environment that takes your infrastructure to the next level. Now go forth and migrate confidently!

For more best practices on moving entire applications among clouds and on‑premises, download The Gorilla Guide to Kubernetes Native Application Mobility. 

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