Cluster API vs kOps

Cluster API is an open-source project for managing the lifecycle of multiple Kubernetes clusters through declarative APIs and tooling. Platform operators can use it to create, scale, upgrade, and destroy Kubernetes-conformant clusters across on-premises and cloud environments. Provider implementations are interchangeable; kubeadm is the default bootstrap provider. The ecosystem includes infrastructure, bootstrap, control plane, IPAM, addon, and runtime extensions, with environments such as AWS, Azure, GCP, OpenStack, vSphere, and KubeVirt. A management cluster can use clusterctl or the Cluster API Operator to manage provider components. Clusterctl fetches provider component YAML and installs it, while the Operator uses a declarative approach intended to support GitOps workflows. Getting started requires an existing Kubernetes cluster accessible through kubectl; kind, Docker, and Helm are common prerequisites. Cluster API supports multi-cluster provisioning and upgrades, but does not manage a single cluster spanning multiple infrastructure providers or clusters it did not provision. It is free and open source. The project supports its latest two minor releases, with each supported for roughly 12 months including maintenance.

kOps is a free, open-source tool for creating, upgrading, maintaining, and destroying production-grade, highly available Kubernetes clusters. It also provisions the cloud infrastructure those clusters require, with the control plane managed by the customer. AWS and Google Cloud are officially supported; DigitalOcean, Hetzner, and OpenStack are in beta, while Azure is in alpha.

Configuration uses a YAML manifest-based API with templating and dry-run modes. State synchronization supports dry runs and automatic idempotency, and kOps can generate Terraform. It offers popular CNI networking providers out of the box and supports ARM64 architectures. kOps runs on Linux, macOS, and Windows; kubectl is required to install and use it. SSH access to masters and nodes is allowed from any address by default, although no public key is installed by default. SSH sources can be restricted in cluster configuration or with a command option. The security documentation says Pods can access the underlying instance IAM role and describes its permission scope as broad. The project points users to public office hours and Kubernetes Slack channels for support.