k3s & k3d Basic

k3s

Lightweight Kubernetes

官方站点：https://k3s.io

官方仓库：https://github.com/rancher/k3s

安装

将k3s安装成为服务：

curl -sfL https://get.k3s.io | sh -
# 添加worker节点
curl -sfL https://get.k3s.io | K3S_URL=https://k3s-server:6443 K3S_TOKEN=`ssh k3s-server  cat /var/lib/rancher/k3s/server/node-token` sh -

A kubeconfig file is written to /etc/rancher/k3s/k3s.yaml.

手动安装使用k3s：

1. Download k3s from latest release (opens new window), x86_64, armhf, and arm64 are supported.
2. Run server.

sudo k3s server &
# Kubeconfig is written to /etc/rancher/k3s/k3s.yaml
sudo k3s kubectl get nodes

# On a different node run the below. NODE_TOKEN comes from
# /var/lib/rancher/k3s/server/node-token on your server
sudo k3s agent --server https://myserver:6443 --token ${NODE_TOKEN}

k3d 简介

k3d is a lightweight wrapper to run k3s (Rancher Lab’s minimal Kubernetes distribution) in docker. k3d makes it very easy to create single- and multi-node k3s clusters in docker, e.g. for local development on Kubernetes.

官方站点: https://k3d.io

安装

linux系统下

# use the install script to grab the latest release:
wget: wget -q -O - https://raw.githubusercontent.com/rancher/k3d/main/install.sh | bash
# 或者
curl: curl -s https://raw.githubusercontent.com/rancher/k3d/main/install.sh | bash

Windows系统下

从官方仓库 (opens new window)中下载对应的包, 配置好环境变量即可.

集群部署

单节点部署:

k3d cluster create mycluster

多节点部署:

k3d cluster create multiserver --servers 3
# 向已存在的集群中添加节点
k3d node create newserver --cluster multiserver --role server
# 部署两个agent节点
k3d cluster create --api-port 6550 -p "8081:80@loadbalancer" --agents 2

输出kubeconfig信息

k3d kubeconfig write k3s-default

暴露服务

1. via Ingress

In this example, we will deploy a simple nginx webserver deployment and make it accessible via ingress. Therefore, we have to create the cluster in a way, that the internal port 80 (where the traefik ingress controller is listening on) is exposed on the host system.

1. Create a cluster, mapping the ingress port 80 to localhost:8081

   k3d cluster create --api-port 6550 -p "8081:80@loadbalancer" --agents 2

   Good to know

   • --api-port 6550 is not required for the example to work. It’s used to have k3s‘s API-Server listening on port 6550 with that port mapped to the host system.
   • the port-mapping construct8081:80@loadbalancermeans
     • map port 8081 from the host to port 80 on the container which matches the nodefilter loadbalancer
   • theloadbalancernodefilter matches only theserverlb that’s deployed in front of a cluster’s server nodes
     • all ports exposed on the serverlb will be proxied to the same ports on all server nodes in the cluster

2. Get the kubeconfig file

   export KUBECONFIG="$(k3d kubeconfig write k3s-default)"

3. Create a nginx deployment

   kubectl create deployment nginx --image=nginx

4. Create a ClusterIP service for it

   kubectl create service clusterip nginx --tcp=80:80

5. Create an ingress object for it with kubectl apply -f Note: k3s deploys traefik (opens new window) as the default ingress controller

   apiVersion: extensions/v1beta1
   kind: Ingress
   metadata:
     name: nginx
     annotations:
       ingress.kubernetes.io/ssl-redirect: "false"
   spec:
     rules:
     - http:
         paths:
         - path: /
           backend:
             serviceName: nginx
             servicePort: 80
   

6. Curl it via localhost

   curl localhost:8081/

2. via NodePort

1. Create a cluster, mapping the port 30080 from agent-0 to localhost:8082

   k3d cluster create mycluster -p "8082:30080@agent[0]" --agents 2

   • Note: Kubernetes’ default NodePort range is 30000-32767 (opens new window)
   • Note: You may as well expose the whole NodePort range from the very beginning, e.g. via k3d cluster create mycluster --agents 3 -p "30000-32767:30000-32767@server[0]" (See this video from @portainer (opens new window))

… (Steps 2 and 3 like above) …

1. Create a NodePort service for it with kubectl apply -f

   apiVersion: v1
   kind: Service
   metadata:
     labels:
       app: nginx
     name: nginx
   spec:
     ports:
     - name: 80-80
       nodePort: 30080
       port: 80
       protocol: TCP
       targetPort: 80
     selector:
       app: nginx
     type: NodePort
   

2. Curl it via localhost

   curl localhost:8082/

参考链接

• k3d官方github仓库: https://github.com/rancher/k3d

• k3d Documentation: https://k3d.io/