Kubernetes alternatives

It is evident that Kubernetes is a robust and widely used container orchestration platform; however, it is not the only option available. Some of the reasons you will need to seek alternatives are the following:

• Complexity and learning curve: Kubernetes is highly complex, and it requires deep knowledge of its architecture, components, and operational best practices.
• Resource intensive: Running Kubernetes requires significant computational resources (CPU, memory, and storage) for both the control plane and worker nodes. This can be costly.
• Specialized use cases: Specialized orchestration tools can provide better performance and efficiency for specific workloads.

Here, we will explore some good alternatives to Kubernetes, each with its own features, advantages, and disadvantages.

Rancher

Rancher is an open source solution designed to help DevOps and developers to administer and deploy multiple Kubernetes clusters. It is not really an alternative to Kubernetes but more of a complementary solution to help orchestrating containers; it is an extension of the functionalities of Kubernetes. The management of the infrastructure can be performed easily, simplifying the operational burden of maintaining a medium and large environment.

Rancher has a variety of features worth looking at:

• It implements RBAC controls across multiple clusters, securing multi-tenant scenarios where different projects or applications can span and run on different clusters simultaneously.
• For troubleshooting purposes, it can help by monitoring, logging, and alerting for any issue on the application side. It supports the integration of several logging tools, such as Splunk, Kafka, and Loki.
• The provisioning of new clusters is one of Rancher’s most popular features. Through a single console, Rancher can deploy Kubernetes clusters across bare-metal, virtualized, and cloud environments. Rancher supports a built-in distribution known as Rancher Kubernetes Engine (RKE). RKE simplifies and automates the implementation and operation of Kubernetes, running seamlessly on Docker containers.
• Automating the provisioning, management, and configuration of the underlying infrastructure that supports Kubernetes clusters. This feature makes it very easy and friendly to manage and scale new infrastructure resources such as worker nodes, control planes, and some other components.

K3s

K3s [4] is a lightweight Kubernetes platform packaged as a single 65 MB binary. It is great for Edge, Internet of Things (IoT), and ARM (previously Advanced RISC Machine, originally Acorn RISC Machine) devices. ARM is a family of reduced instruction set computing (RISC) architectures for computer processors, configured for various environments. K3s is supposed to be fully compliant with Kubernetes. One significant difference between Kubernetes and K3s is that K3 uses an embedded SQLite database as a default storage mechanism, while Kubernetes uses etcd as its default storage server. K3s works great on something as small as a Raspberry Pi. For highly available configurations, an embedded etcd datastore can be used instead.

OpenShift

Red Hat OpenShift is a hybrid platform to build and deploy applications at scale.

OpenShift version 3 adopted Docker as its container technology and Kubernetes as its container orchestration technology. In version 4, OpenShift switched to CRI-O as the default container runtime. As of today, OpenShift’s self-managed container platform is version 4.15.

OpenShift versus Kubernetes

OpenShift and Kubernetes are both powerful platforms for managing containerized applications, but they serve slightly different purposes. There are many differences that you will learn next, but one notable example is the ease of use offered by OpenShift, which comes with an installer and pre-configured settings for easier deployment while, for example, Kubernetes requires additional setup and configuration for a production-ready environment.

Naming

Objects named in Kubernetes might have different names in OpenShift, although sometimes their functionality is alike. For example, a namespace in Kubernetes is called a project in OpenShift, and project creation comes with default objects. The project is a Kubernetes namespace with additional annotations. Ingress in Kubernetes is called routes in OpenShift. Routes were introduced earlier than Ingress objects. Routes in OpenShift are implemented by HAProxy, while there are many ingress controller options in Kubernetes. Deployment in Kubernetes is called DeploymentConfig, and OpenShift implements both Kubernetes Deployment objects and OpenShift Container Platform DeploymentConfig objects. Users may select but consider that the implementation is different.

Security

Kubernetes is open and less secure by default. OpenShift is relatively closed and offers a handful of good security mechanisms to secure a cluster. For example, when creating an OpenShift cluster, DevOps can enable the internal image registry, which is not exposed to the external one. At the same time, the internal image registry serves as the trusted registry where the image will be pulled and deployed. There is another thing that OpenShift projects do better than Kubernetes namespaces—when creating a project in OpenShift, you can modify the project template and add extra objects, such as NetworkPolicy and default quotas, to the project that are compliant with your company’s policy. It also helps hardening, by default.

For customers that require a stronger security model, Red Hat OpenShift provides Red Hat Advanced Cluster Security [5], which is included on the Red Hat OpenShift Platform Plus, and is a complete set of powerful tools to protect the environment.

Cost

OpenShift is a product offered by Red Hat, although there is a community version project called OpenShift Origin. When people talk about OpenShift, they usually mean the paid option of the OpenShift product with support from Red Hat. Kubernetes is a completely free open source project.

HashiCorp Nomad

Nomad offers support for both open source and enterprise licenses. It is a simple and adaptable scheduler and orchestrator designed to efficiently deploy container applications across on-premises and cloud environments, seamlessly accommodating large-scale operations.

Where Nomad plays an important role is in automating streamlining application deployments, offering an advantage over Kubernetes, which often demands specialized skills for implementation and operation.

It is built into a single lightweight binary and supports all major cloud providers and on-premises installations.

Its key features include the following:

• Accelerated adoption leading to swift time-to-production
• Facilitated migration pathways from alternative platforms and applications
• Simplified maintenance and troubleshooting, reducing personnel requirements while ensuring high uptime

When compared to Kubernetes, Kubernetes benefits from more extensive community support, as an open-source platform. Kubernetes also has greater maturity, has great support from major cloud providers, and offers superior flexibility and portability.

Minikube

Minikube is the single-node cluster version of Kubernetes that can be run on Linux, macOS, and Windows platforms. Minikube supports standard Kubernetes features, such as LoadBalancer, services, PersistentVolume, Ingress, container runtimes, and support for add-ons and GPU.

Minikube is a great starting place to get hands-on experience with Kubernetes. It’s also a good place to run tests locally or work on proof of concepts. However, it is not intended for production workloads.

Having examined a range of alternatives to Kubernetes for container orchestration, we will now transition to a section dedicated to exploring cloud providers and their contributions to this domain. This discussion will focus on the support, tools, and services offered by leading cloud platforms to facilitate containerized workloads and orchestration.