https://github.com/cstanislawski/kubelift
Kubernetes cluster operations over SSH
https://github.com/cstanislawski/kubelift
automation cncf devops k8s kubeadm kubernetes kubernetes-setup kubernetes-upgrade kubernetes-utils learnk8s vm
Last synced: about 2 months ago
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Kubernetes cluster operations over SSH
- Host: GitHub
- URL: https://github.com/cstanislawski/kubelift
- Owner: cstanislawski
- License: apache-2.0
- Created: 2024-10-16T19:12:04.000Z (7 months ago)
- Default Branch: main
- Last Pushed: 2024-10-25T17:41:18.000Z (7 months ago)
- Last Synced: 2025-02-09T03:41:17.394Z (4 months ago)
- Topics: automation, cncf, devops, k8s, kubeadm, kubernetes, kubernetes-setup, kubernetes-upgrade, kubernetes-utils, learnk8s, vm
- Language: Shell
- Homepage:
- Size: 80.1 KB
- Stars: 0
- Watchers: 1
- Forks: 0
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
- License: LICENSE.md
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README
# kubelift
Kubernetes cluster operations over SSH
## Goal
The goal of this project is to provide a simple tool to provision a Kubernetes cluster on VMs over SSH. By going with a script-based approach, you can easily customize the installation process to fit your needs, and fail fast if something goes wrong.
`kubelift` aims to be a bridge between the manual operations with `kubeadm` and the automated installation with `kubespray` requiring a lot of setup.
## Requirements
- A set of VM(s) with SSH access
- Sudo privileges without password prompt (NOPASSWD in sudoers) for the SSH user
- Internet connectivity on all nodes
## Features
- **Noninteractive mode** for automated operations
- **SSH-based Operations** for secure remote management
- **Seamless Upgrades** for managing cluster lifecycle
- **Input Validation** ensures all provided parameters are correct
- **Modular Design** for better maintainability
## Installation
### Quick Setup
```bash
curl -LO https://raw.githubusercontent.com/cstanislawski/kubelift/main/kubelift.sh
chmod +x kubelift.sh
```
### System-wide Installation
```bash
sudo curl -L https://raw.githubusercontent.com/cstanislawski/kubelift/main/kubelift.sh -o /usr/local/bin/kubelift
sudo chmod +x /usr/local/bin/kubelift
```
## Usage
```bash
kubelift --help
Usage: kubelift [options...]
Operations:
create Create a new Kubernetes cluster
upgrade Upgrade an existing Kubernetes cluster
cleanup Remove Kubernetes cluster
Options:
-h, --help Display this help message
--noninteractive Enable or disable noninteractive mode
--ssh-user Username to use for SSH connection
--kubernetes-version Kubernetes version to install (create/upgrade only)
--control-plane-ip Control plane node IP address
--worker-ips Worker node IP addresses (create only)
--enable-control-plane-workloads Enable control plane scheduling (create only)
--skip-reqs Skip minimum requirements validation
--nuke Perform deep cleanup (cleanup only)
```
### Cluster Creation
```bash
./kubelift.sh create \
--noninteractive \
--ssh-user \
--kubernetes-version \
--control-plane-ip \
--worker-ips \
--enable-control-plane-workloads
```
The create operation will:
- Validate all input parameters
- Check SSH access to all specified nodes
- Prepare each node by:
- Installing Docker and containerd
- Installing kubeadm, kubectl, and kubelet
- Configuring the cgroup driver
- Initialize the control plane node
- Join worker nodes to the cluster
- Install the CNI plugin (Flannel)
- Optionally enable scheduling on the control plane node
### Cluster Upgrade
```bash
./kubelift.sh upgrade \
--noninteractive \
--ssh-user \
--kubernetes-version \
--control-plane-ip
```
The upgrade operation will:
- Validate all input parameters
- Check SSH access to all nodes
- Verify version differences between current and target
- Check availability of target Kubernetes components
- Upgrade the control plane node
- Upgrade worker nodes (if present)
### Cluster Cleanup
```bash
./kubelift.sh cleanup \
--noninteractive \
--ssh-user \
--control-plane-ip \
--nuke # Optional
```
The cleanup operation will:
- Remove the Kubernetes cluster using kubeadm reset
- Clean up both control plane and worker nodes
- Preserve CNI configuration
## Configuration / Environment Variables
The scripts use the following environment variables:
### General variables
- `NONINTERACTIVE`: Enable or disable noninteractive mode (true/false)
- `SSH_USER`: SSH user for connecting to the nodes
- `KUBERNETES_VERSION`: Kubernetes version to install/upgrade to
- `CONTROL_PLANE_IP`: IP address of the control plane node
### Cluster creation variables
- `WORKER_IPS`: Comma-separated list of worker node IP addresses
- `ENABLE_CONTROL_PLANE_WORKLOADS`: Enable scheduling on control plane node (true/false)
## Limitations and Considerations
- Host OS: Scripts assume one of the latest Ubuntu LTS versions is used on all VMs
- Network: Scripts assume the VMs have internet connectivity
- Minimum Resources: Ensure VMs meet the minimum Kubernetes system requirements
- CNI Plugin: Scripts install Flannel as the default CNI plugin
- Version-specific Limitations: The upgrade script follows a general upgrade path. Specific versions may have additional requirements
- Downgrades: The upgrade script doesn't support downgrading the cluster
## Best Practices
- Always test the scripts in a non-production environment first
- Ensure you have recent backups before performing upgrades
- Review the scripts and understand their operation before running
- Monitor the cluster closely after any operations
## Alternatives
Some of the alternatives you could consider are:
- [kubeadm](https://kubernetes.io/docs/setup/production-environment/tools/kubeadm/create-cluster-kubeadm/) - a tool built to provide best-practice "fast paths" for creating Kubernetes clusters, which `kubelift` is based on
- [kubespray](https://github.com/kubernetes-sigs/kubespray) - a set of Ansible playbooks to provision a Kubernetes cluster
- [kubean](https://github.com/kubean-io/kubean) - an operator for cluster lifecycle management based on kubespray
- [kops](https://github.com/kubernetes/kops) - CLI to create, destroy, upgrade and maintain production-grade Kubernetes clusters hosted on AWS/GCP with more providers in Beta/Alpha
- [k3sup](https://github.com/alexellis/k3sup) - k3s cluster installer over SSH
## TODO - unordered
## CI
- Add BATS - Bash Automated Testing System - for testing the scripts
- Consider checkbashisms instead of shellcheck
- Consider bash-language-server analysis
- CodeQL analysis for security scanning
- Add E2E tests with kind/k3d/Vagrant
## High Priority
- Allow custom CIDR ranges
- Add support for additional logging output to a file
- Add dry-run mode for operations
## Medium Priority
- Add support for more CNI plugins: Calico, Cilium
- Cluster configuration templating
- Add support for HA control plane
- Add downgrades support
- Assume presence of the flag equals true (e.g. --noninteractive) if the flag is present
- Add k3s support
- Add support for more Linux distributions
## Low Priority
- Air-gapped environments support