Kubernetes adoption has snowballed in the last couple of years. Organizations have leveraged Kubernetes to streamline their workloads and increase their productivity. This cloud-native platform has a lot to offer to organizations looking to venture into the world of the cloud. Kubernetes is cloud-native, but it’s not limited to the cloud. Many organizations, for varied reasons, don’t want to move away from their on-prem infrastructure. These organizations can still use Kubernetes to bring cloud-native features like high availability, increased scalability, and flexibility to on-premises workloads.
Why stick with on-prem?
Despite a drastic shift towards cloud-native infrastructure, a huge number of organizations are not fully on board with the idea of migration. This is due to multiple reasons. Some organizations are satisfied with their current deployments and don’t see a point in carrying out a complex migration that will break the bank. Others are cynical about their critical data being on the private or public cloud, which is not an illegitimate fear. Some organizations have adopted the hybrid cloud infrastructure, which means they still rely on the on-premises datacenters to run their workloads. However, organizations still want to benefit from Kubernetes to bring the cloud-native functionality to their bare-metal setup. This can help ease the process of migration or integration with cloud-native workloads in the future.
Challenges of bringing Kubernetes on-premises
Bringing cloud-native functionality to your on-prem workloads can get complicated. The problem with an on-premises k8s setup is starting from scratch. An organization looking to venture into this territory will need a team of K8s experts who can set everything up. The complications arise because you are forced to address all the complexities that managed k8s take care of for you. You will have to address load balancing, storage management, deployment automation, SDN management, security, and authentication, among many other complexities. And, the biggest catch of all is that your organization is responsible for everything, including upgrading your clusters every time a new k8s version is released. This makes human error more than just a mere probability. These are the reasons why various organizations rely on enterprise-ready k8s solutions that can take care of everything for you.
To undertake such a huge project, organizations will have to find K8s experts. Since K8s is still fairly new, finding K8s admins can be especially hard. There are various certifications provided by the CNCF to access developers’ Kubernetes expertise like CKA (Kubernetes administrator) and CKAD (Kubernetes application developer). However, sometimes organizations don’t want to hire a team of experts. In that case, bringing k8s to on-prem can be exponentially more tedious. Not all organizations that want to venture into this direction will get the results they want in the time allocated to this particular project. This can lead to the project getting delayed and costs adding up. Another important consideration is visibility and observability. With k8s, the idea is always to make the workloads be distributed, which can be great for migration and portability but proves complicated for monitoring. A development team working on a DIY, on-prem, Kubernetes solution will have to implement an efficient monitoring functionality. Organizations should consider all these complexities and plan everything.
Best practices for on-premises Kubernetes
Here are some of the important best practices you should follow while implementing in-house, on-premises k8s.
- Deploying a dynamic load balancer that can adjust to the growing size of your cluster should be your priority. Make sure the load balancer can automatically accommodate any changes in your cluster.
- Implement VMs wherever isolation is necessary. Try using SDNs to implement secure and isolated sub-networks.
- Start with smaller clusters to limit the blast radius. This is an efficient way of handling all faults. You can later converge your clusters to form bigger clusters when you have efficient monitoring in place.
- To achieve scalability in storage, you should implement machine rotation so you don’t run out of memory while your workloads are running.
- Make sure all the operating systems and drivers are up to date.
- Make sure you have a minimum of three servers to run K8s on-premises. One server should be reserved for the master components that act as the control pane. The other two should run the worker nodes where kubelet is hosted.
- An SSD is an important recommendation. It will be able to keep up with the speed at which etcd writes to the disk and help avoid any performance issues.
- Kubelet should be running on all the nodes to ensure all the containers in a node are running properly.
What comes next?
Once your Kubernetes infrastructure is ready, you will need some integrations that can help with making your on-prem k8s more cloud-like. You will need to install repositories for any open-source solutions you might integrate into your on-prem k8s infrastructure for air-gapped deployments. You would also need to install the Kubernetes dashboard plugin to visualize your Kubernetes infrastructure. Tools like Grafana and Prometheus can be integrated with your on-prem K8s to provide extensive observability. You can also implement Istio or Linkerd for employing the service mesh functionality. And, tools like Weaveworks and Flannel can be great options to address any networking woes. Security is really important when it comes to running distributed workloads. Organizations should implement zero-trust security and implement RBAC and multifactor authentication to avoid attacks. All open source components and codes should be vetted properly to eliminate any risks.
There is an easier way
Kubernetes on-premises is a daunting task if you opt for the DIY approach. There are easier alternatives for organizations that aren’t bound by regulations to not rely on third-party vendors. A plethora of platform-as-a-service (PaaS) and Kube-native solutions exist in the market that can take care of all your needs when setting up k8s on-premises. PaaS solutions like VMware Enterprise PKS and RedHat OpenShift are quite popular and address many complexities that on-premises K8s has to offer. Kube-native solutions like Rancher 2.0 and Kublr can cover all your requirements from networking and load balancing to monitoring and security. It’s important that organizations weigh their options and go for the solutions that work best for their specific use-case.
Kubernetes is not hard to implement. It’s the operations that can be hard to set up. This can become exponentially more challenging when you have to build your infrastructure from scratch. It’s vital that you meet all your requirements and follow the correct best practices. Implementing security and taking care of all the complexities is quite possible if your strategy is right. In the end, having an on-prem K8s platform provides you with the flexibility and high availability that wasn’t possible with the existing monolithic infrastructure. For many organizations, it opens the avenues to hybrid cloud that is the most efficient cloud-native infrastructure. Organizations can have the liberty to pick and choose parts of their workloads they want to keep on-prem or on a cloud platform making for more efficient and giggly available workloads. In the future, implementing on-premises Kubernetes will only get easier.
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