k3s - k3d Basic

k3s & k3d Basic

k3s

Lightweight Kubernetes

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：

Download k3s from latest release, x86_64, armhf, and arm64 are supported.
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.
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

Get the kubeconfig file

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

Create a nginx deployment

kubectl create deployment nginx --image=nginx

Create a ClusterIP service for it

kubectl create service clusterip nginx --tcp=80:80
Create an ingress object for it with kubectl apply -f Note: k3s deploys traefik 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
Curl it via localhost

curl localhost:8081/
2. via NodePort

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

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)

… (Steps 2 and 3 like above) …
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
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/