alexellis/k3sup
K3sup
k3sup is a command-line tool that installs and manages lightweight Kubernetes clusters entirely over SSH, without requiring any pre-installed software on the target machines. It bootstraps clusters on remote hosts using a single statically-linked binary, then provides immediate kubectl access by fetching and merging the cluster's admin credentials into the local configuration. The tool supports plan-driven cluster topology, allowing users to define node roles and configuration in a YAML file for automated multi-node deployment.
The tool distinguishes itself by enabling parallel execution of installation and management commands across all specified hosts, minimizing setup time for multi-node clusters. It supports building highly available clusters with multi-master control planes using embedded etcd or external SQL datastores, and can add worker nodes to an existing cluster over SSH. k3sup also handles cluster teardown in the correct order, and can run arbitrary shell commands simultaneously on every node in a cluster.
Beyond cluster lifecycle management, the tool includes capabilities for verifying cluster readiness by checking that all nodes report a Ready status. The project provides cross-platform binary compilation for Linux, macOS, and Windows across multiple architectures, along with automated code quality checks including formatting verification and unit test coverage reporting.