K3s 1.21: Lightweight Kubernetes for Edge and IoT

Introduction

K3s 1.21 — Lightweight Kubernetes for Edge and IoT — was released on May 21, 2021.

Edge clusters force trade-offs: less compute, worse connectivity, and a stronger need for simple operations.

In this release: K3s 1.21 delivers a lightweight Kubernetes distribution with enhanced performance, better ARM support, and improved security for edge and resource-constrained environments.

Performance Improvements

• Startup time optimizations reduce cluster initialization time.
• Resource usage improvements reduce CPU and memory footprint.
• Network performance enhancements reduce latency for pod-to-pod communication.
• Storage optimizations improve I/O performance for stateful workloads.

ARM Support

1. ARM64 improvements provide better performance and compatibility.
2. ARM32 support expansion enables deployment on more edge devices.
3. Cross-compilation tools simplify building K3s for different architectures.
4. Device compatibility expansion supports more ARM-based edge devices.

Security Enhancements

• Certificate management improvements simplify TLS certificate handling.
• RBAC enhancements provide better access control for edge deployments.
• Network policies support enables applying security policies to edge workloads.
• Audit logging expansion tracks security-relevant events.

Edge Features

• Offline operation improvements enable K3s to operate during connectivity issues.
• Update mechanisms enhancements simplify updating edge clusters.
• Monitoring expansion includes edge-specific metrics and health indicators.
• Documentation improvements provide clearer guides for edge deployments.

Getting Started

curl -sfL https://get.k3s.io | sh -
kubectl get nodes

Summary

K3s 1.21 continues to evolve as a leading lightweight Kubernetes distribution, enabling cloud-native applications at the edge.