k3s部署过程
介绍
K3s集群分为k3s Server(控制平面)和k3s Agent(工作节点)。所有的组件都打包在单个二进制文件中。
运行环境
IP地址根据实际情况而定
步骤
# 关闭防火墙
systemctl disable firewalld --now
# 设置selinux(需要联网)
yum install -y container-selinux selinux-policy-base
yum install -y https://rpm.rancher.io/k3s/latest/common/centos/7/noarch/k3s-selinux-0.2-1.el7_8.noarch.rpm
每个主机都要执行以下操作：
文件上传
# 打开目录
cd /home
# 安装上传工具
yum -y install lrzsz
# 上传三个文件
rz
在/home目录下上传这三个文件：【链接：https://pan.baidu.com/s/18xbh5Ofvg8-TqimXKZcLMQ 提取码：te58 】
处理
install.sh脚本
- 先下载脚本 or 复制脚本到install.sh
- 格式化
yum install dos2unix -y
dos2unix ./install.sh
移动文件
mv k3s /usr/local/bin
chmod +x /usr/local/bin/
mkdir -p /var/lib/rancher/k3s/agent/images/
cp ./k3s-airgap-images-amd64.tar.gz /var/lib/rancher/k3s/agent/images/
k8s-master【192.168.31.204】
#修改权限
chmod +x install.sh
#离线安装
INSTALL_K3S_SKIP_DOWNLOAD=true ./install.sh
#安装完成后，查看节点状态
kubectl get node
#查看token
cat /var/lib/rancher/k3s/server/node-token
k8s-work1 【192.168.31.180】和 k8s-work2【192.168.31.146】
INSTALL_K3S_SKIP_DOWNLOAD=true \
K3S_URL=https://192.168.31.204:6443 \
K3S_TOKEN=K10e6745f7fb6e204a4e2a8c5a12df4b3b2b3ff4b52034421c3ed1a168c3ef4be56::server:23e98714cdfd960face1a4064da62f7a \
./install.sh
k8s-master
安装完毕后执行
watch -n 1 kubectl get node
# 若安装失败，修改主机名称
vim /etc/hostname
# 删除默认主机名
kubectl delete node localhost.localdomain
查看 containerd 日志
ps -ef | grep containerd
cat /var/lib/rancher/k3s/agent/etc/containerd/config.toml
我们需要在每个节点上新建 /etc/rancher/k3s/registries.yaml 文件，配置内容如下：
mirrors:
docker.io:
endpoint:
- "https://fsp2sfpr.mirror.aliyuncs.com/"
配置镜像
cd /etc/rancher/k3s/
# 新建并插入镜像源
vim /etc/rancher/k3s/registries.yaml
# 重启 k8s-master
systemctl restart k3s
# 重启 k8s-work1和k8s-work2
systemctl restart k3s-agent
cat /var/lib/rancher/k3s/agent/etc/containerd/config.toml
创建和管理 Pod
kubectl run mynginx --image=nginx
# 查看Pod
kubectl get pod
# 描述
kubectl describe pod mynginx
# 查看Pod的运行日志
kubectl logs mynginx
# 显示pod的IP和运行节点信息
kubectl get pod -owide
# 使用Pod的ip+pod里面运行容器的端口
curl 10.42.4.5
#在容器中执行
kubectl exec mynginx -it -- /bin/bash
kubectl get po --watch
# -it 交互模式
# --rm 退出后删除容器，多用于执行一次性任务或使用客户端
kubectl run mynginx --image=nginx -it --rm -- /bin/bash
# 删除
kubectl delete pod mynginx
# 强制删除
kubectl delete pod mynginx --force
# 强制删除
kubectl get pod
kubectl delete pod label-demo -n default --force --grace-period=0
部署 和 副本集
**Deployment**是对ReplicaSet和Pod更高级的抽象。
它使Pod拥有多副本，自愈，扩缩容、滚动升级等能力。
ReplicaSet(副本集)是一个Pod的集合。
它可以设置运行Pod的数量，确保任何时间都有指定数量的 Pod 副本在运行。
通常我们不直接使用ReplicaSet，而是在Deployment中声明。
#创建deployment,部署3个运行nginx的Pod
kubectl create deployment nginx-deploy --image=nginx:1.22 --replicas=3
#查看deployment
kubectl get deploy
#查看replicaSet
kubectl get rs
#删除deployment
kubectl delete deploy nginx-deploy
自愈能力
–replicas=3 表示副本集的pod数量为3
[root@k8s-master k3s]# kubectl get rs
NAME DESIRED CURRENT READY AGE
nginx-deploy-855866bb46 3 3 3 16s
[root@k8s-master k3s]# kubectl get pod
NAME READY STATUS RESTARTS AGE
nginx-deploy-855866bb46-h8ppk 1/1 Running 0 71s
nginx-deploy-855866bb46-7xxtb 1/1 Running 0 71s
nginx-deploy-855866bb46-cfc9c 1/1 Running 0 71s
删除其中一个pod，会自动 补齐 一个
[root@k8s-master k3s]# kubectl delete pod nginx-deploy-855866bb46-cfc9c
pod "nginx-deploy-855866bb46-cfc9c" deleted
[root@k8s-master k3s]# kubectl get pod
NAME READY STATUS RESTARTS AGE
nginx-deploy-855866bb46-h8ppk 1/1 Running 0 4m16s
nginx-deploy-855866bb46-7xxtb 1/1 Running 0 4m16s
nginx-deploy-855866bb46-vk7lr 1/1 Running 0 9s
自动扩容
[root@k8s-master ~]# kubectl get replicaSet --watch
NAME DESIRED CURRENT READY AGE
nginx-deploy-855866bb46 3 3 3 9m41s
nginx-deploy-855866bb46 5 3 3 10m
nginx-deploy-855866bb46 5 3 3 10m
nginx-deploy-855866bb46 5 5 3 10m
nginx-deploy-855866bb46 5 5 4 10m
nginx-deploy-855866bb46 5 5 5 10m
#将副本数量调整为5
kubectl scale deploy nginx-deploy --replicas=5
kubectl get deploy
自动缩放
自动缩放通过增加和减少副本的数量，以保持所有 Pod 的平均 CPU 利用率不超过 75%。
自动伸缩需要声明Pod的资源限制，同时使用 Metrics Server 服务（K3s默认已安装）。
#自动缩放
kubectl autoscale deployment/nginx-auto --min=3 --max=10 --cpu-percent=75
#查看自动缩放
kubectl get hpa
#删除自动缩放
kubectl delete hpa nginx-deployment
滚动更新
#查看版本和Pod
[root@k8s-master ~]# kubectl get deploy -owide
NAME READY UP-TO-DATE AVAILABLE AGE CONTAINERS IMAGES SELECTOR
nginx-deploy 3/3 3 3 16m nginx nginx:1.22 app=nginx-deploy
#更新容器镜像
kubectl set image deploy/nginx-deploy nginx=nginx:1.23
#查看过程
[root@k8s-master ~]# kubectl get rs --watch
NAME DESIRED CURRENT READY AGE
nginx-deploy-855866bb46 3 3 3 22m
nginx-deploy-7c9c6446b7 0 0 0 2m27s
nginx-deploy-7c9c6446b7 0 0 0 2m34s
nginx-deploy-7c9c6446b7 1 0 0 2m34s
nginx-deploy-7c9c6446b7 1 0 0 2m34s
nginx-deploy-7c9c6446b7 1 1 0 2m34s
nginx-deploy-7c9c6446b7 1 1 1 2m36s
nginx-deploy-855866bb46 2 3 3 23m
nginx-deploy-7c9c6446b7 2 1 1 2m36s
nginx-deploy-7c9c6446b7 2 1 1 2m36s
nginx-deploy-855866bb46 2 3 3 23m
nginx-deploy-855866bb46 2 2 2 23m
nginx-deploy-7c9c6446b7 2 2 1 2m36s
nginx-deploy-7c9c6446b7 2 2 2 2m38s
nginx-deploy-855866bb46 1 2 2 23m
nginx-deploy-855866bb46 1 2 2 23m
nginx-deploy-7c9c6446b7 3 2 2 2m38s
nginx-deploy-855866bb46 1 1 1 23m
nginx-deploy-7c9c6446b7 3 2 2 2m38s
nginx-deploy-7c9c6446b7 3 3 2 2m38s
nginx-deploy-7c9c6446b7 3 3 3 2m39s
nginx-deploy-855866bb46 0 1 1 23m
nginx-deploy-855866bb46 0 1 1 23m
nginx-deploy-855866bb46 0 0 0 23m
[root@k8s-master ~]# kubectl get deploy -owide
NAME READY UP-TO-DATE AVAILABLE AGE CONTAINERS IMAGES SELECTOR
nginx-deploy 3/3 3 3 26m nginx nginx:1.23 app=nginx-deploy
版本回滚
#查看历史版本
[root@k8s-master k3s]# kubectl rollout history deploy/nginx-deploy
deployment.apps/nginx-deploy
REVISION CHANGE-CAUSE
3 <none>
4 <none>
[root@k8s-master ~]# kubectl get rs
NAME DESIRED CURRENT READY AGE
nginx-deploy-7c9c6446b7 3 3 3 13m
nginx-deploy-855866bb46 0 0 0 33m
#查看指定版本的信息
[root@k8s-master k3s]# kubectl rollout history deploy/nginx-deploy --revision=3
deployment.apps/nginx-deploy with revision #3
Pod Template:
Labels: app=nginx-deploy
pod-template-hash=855866bb46
Containers:
nginx:
Image: nginx:1.22
Port: <none>
Host Port: <none>
Environment: <none>
Mounts: <none>
Volumes: <none>
#回滚到历史版本
[root@k8s-master k3s]# kubectl rollout undo deploy/nginx-deploy --to-revision=3
deployment.apps/nginx-deploy rolled back
[root@k8s-master ~]# kubectl get rs --watch
NAME DESIRED CURRENT READY AGE
nginx-deploy-7c9c6446b7 3 3 3 14m
nginx-deploy-855866bb46 0 0 0 34m
nginx-deploy-855866bb46 0 0 0 35m
nginx-deploy-855866bb46 1 0 0 35m
nginx-deploy-855866bb46 1 0 0 35m
nginx-deploy-855866bb46 1 1 0 35m
nginx-deploy-855866bb46 1 1 1 35m
nginx-deploy-7c9c6446b7 2 3 3 15m
nginx-deploy-855866bb46 2 1 1 35m
nginx-deploy-7c9c6446b7 2 3 3 15m
nginx-deploy-855866bb46 2 1 1 35m
nginx-deploy-7c9c6446b7 2 2 2 15m
nginx-deploy-855866bb46 2 2 1 35m
nginx-deploy-855866bb46 2 2 2 35m
nginx-deploy-7c9c6446b7 1 2 2 15m
nginx-deploy-855866bb46 3 2 2 35m
nginx-deploy-7c9c6446b7 1 2 2 15m
nginx-deploy-7c9c6446b7 1 1 1 15m
nginx-deploy-855866bb46 3 2 2 35m
nginx-deploy-855866bb46 3 3 2 35m
nginx-deploy-855866bb46 3 3 3 35m
nginx-deploy-7c9c6446b7 0 1 1 15m
nginx-deploy-7c9c6446b7 0 1 1 15m
nginx-deploy-7c9c6446b7 0 0 0 15m
[root@k8s-master k3s]# kubectl get pod
NAME READY STATUS RESTARTS AGE
nginx-deploy-855866bb46-4h5jn 1/1 Running 0 2m28s
nginx-deploy-855866bb46-kfq2x 1/1 Running 0 2m27s
nginx-deploy-855866bb46-9xf98 1/1 Running 0 2m26s
Service服务
Service是将运行在一组 Pods 上的应用程序公开为网络服务的抽象方法。
Service为一组 Pod 提供相同的 DNS 名，并且在它们之间进行负载均衡。
Kubernetes 为 Pod 提供分配了IP 地址，但IP地址可能会发生变化。
集群内的容器可以通过service名称访问服务，而不需要担心Pod的IP发生变化。
Type取值
ClusterIP：将服务公开在集群内部。kubernetes会给服务分配一个集群内部的 IP，集群内的所有主机都可以通过这个Cluster-IP访问服务。集群内部的Pod可以通过service名称访问服务。- NodePort：通过每个节点的主机IP 和静态端口（
NodePort）暴露服务。 集群的外部主机可以使用节点IP和NodePort访问服务。 - ExternalName：将集群外部的网络引入集群内部。
- LoadBalancer：使用云提供商的负载均衡器向外部暴露服务。
# port是service访问端口,target-port是Pod端口
# 二者通常是一样的
kubectl expose deploy/nginx-deploy \
--name=nginx-service --type=ClusterIP --port=80 --target-port=80
# 随机产生主机端口
kubectl expose deploy/nginx-deploy \
--name=nginx-service --type=NodePort --port=8080 --target-port=80
查看信息
[root@k8s-master k3s]# kubectl get deploy
NAME READY UP-TO-DATE AVAILABLE AGE
nginx-deploy 3/3 3 3 48m
[root@k8s-master k3s]# kubectl get all
NAME READY STATUS RESTARTS AGE
pod/nginx-deploy-855866bb46-4h5jn 1/1 Running 0 13m
pod/nginx-deploy-855866bb46-kfq2x 1/1 Running 0 13m
pod/nginx-deploy-855866bb46-9xf98 1/1 Running 0 13m
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
service/kubernetes ClusterIP 10.43.0.1 <none> 443/TCP 5d
NAME READY UP-TO-DATE AVAILABLE AGE
deployment.apps/nginx-deploy 3/3 3 3 48m
NAME DESIRED CURRENT READY AGE
replicaset.apps/nginx-deploy-855866bb46 3 3 3 48m
replicaset.apps/nginx-deploy-7c9c6446b7 0 0 0 28m
NAME REFERENCE TARGETS MINPODS MAXPODS REPLICAS AGE
horizontalpodautoscaler.autoscaling/nginx-deploy Deployment/nginx-deploy <unknown>/75% 3 10 3 3h41m
# port是service访问端口,target-port是Pod端口
[root@k8s-master k3s]# kubectl expose deploy/nginx-deploy --name=nginx-service --port=8080 --target-port=80
service/nginx-service exposed
[root@k8s-master k3s]# kubectl get service
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
kubernetes ClusterIP 10.43.0.1 <none> 443/TCP 5d
nginx-service ClusterIP 10.43.177.31 <none> 8080/TCP 2m40s
集群内访问
[root@k8s-master k3s]# curl 10.43.177.31:8080
<!DOCTYPE html>
<html>
<head>
<title>Welcome to nginx!</title>
<style>
html { color-scheme: light dark; }
body { width: 35em; margin: 0 auto;
font-family: Tahoma, Verdana, Arial, sans-serif; }
</style>
</head>
<body>
<h1>Welcome to nginx!</h1>
<p>If you see this page, the nginx web server is successfully installed and
working. Further configuration is required.</p>
<p>For online documentation and support please refer to
<a href="http://nginx.org/">nginx.org</a>.<br/>
Commercial support is available at
<a href="http://nginx.com/">nginx.com</a>.</p>
<p><em>Thank you for using nginx.</em></p>
</body>
</html>
容器内访问
[root@k8s-master k3s]# kubectl run test -it --image=nginx:1.22 --rm -- bash
If you don't see a command prompt, try pressing enter.
root@test:/# curl nginx-service:8080
<!DOCTYPE html>
<html>
<head>
<title>Welcome to nginx!</title>
<style>
html { color-scheme: light dark; }
body { width: 35em; margin: 0 auto;
font-family: Tahoma, Verdana, Arial, sans-serif; }
</style>
</head>
<body>
<h1>Welcome to nginx!</h1>
<p>If you see this page, the nginx web server is successfully installed and
working. Further configuration is required.</p>
<p>For online documentation and support please refer to
<a href="http://nginx.org/">nginx.org</a>.<br/>
Commercial support is available at
<a href="http://nginx.com/">nginx.com</a>.</p>
<p><em>Thank you for using nginx.</em></p>
</body>
</html>
[root@k8s-master ~]# kubectl describe service nginx-service
Name: nginx-service
Namespace: default
Labels: app=nginx-deploy
Annotations: <none>
Selector: app=nginx-deploy
Type: ClusterIP
IP Family Policy: SingleStack
IP Families: IPv4
IP: 10.43.177.31
IPs: 10.43.177.31
Port: <unset> 8080/TCP
TargetPort: 80/TCP
Endpoints: 10.42.1.12:80,10.42.2.16:80,10.42.4.13:80
Session Affinity: None
Events: <none>
进入其中一个pod并修改文件
[root@k8s-master ~]# kubectl get pod
NAME READY STATUS RESTARTS AGE
nginx-deploy-855866bb46-4h5jn 1/1 Running 0 43m
nginx-deploy-855866bb46-kfq2x 1/1 Running 0 43m
nginx-deploy-855866bb46-9xf98 1/1 Running 0 43m
test 1/1 Running 0 19m
[root@k8s-master ~]# kubectl exec -it nginx-deploy-855866bb46-9xf98 -- bash
root@nginx-deploy-855866bb46-9xf98:/# cd /usr/share/nginx/html/
root@nginx-deploy-855866bb46-9xf98:/usr/share/nginx/html# ls
50x.html index.html
root@nginx-deploy-855866bb46-9xf98:/usr/share/nginx/html# echo hello > index.html
root@nginx-deploy-855866bb46-9xf98:/usr/share/nginx/html# exit
exit
Pod在后端实现了负载均衡
[root@k8s-master ~]# curl 10.43.177.31:8080
hello
[root@k8s-master ~]# curl 10.43.177.31:8080
<!DOCTYPE html>
<html>
<head>
<title>Welcome to nginx!</title>
<style>
html { color-scheme: light dark; }
body { width: 35em; margin: 0 auto;
font-family: Tahoma, Verdana, Arial, sans-serif; }
</style>
</head>
<body>
<h1>Welcome to nginx!</h1>
<p>If you see this page, the nginx web server is successfully installed and
working. Further configuration is required.</p>
<p>For online documentation and support please refer to
<a href="http://nginx.org/">nginx.org</a>.<br/>
Commercial support is available at
<a href="http://nginx.com/">nginx.com</a>.</p>
<p><em>Thank you for using nginx.</em></p>
</body>
</html>
主机外部访问
k8s-master
k8s-work1
k8s-work2
命名空间
**命名空间(Namespace)**是一种资源隔离机制，将同一集群中的资源划分为相互隔离的组。
命名空间可以在多个用户之间划分集群资源（通过资源配额）。
- 例如我们可以设置开发、测试、生产等多个命名空间。
同一命名空间内的资源名称要唯一，但跨命名空间时没有这个要求。
初始命名空间
Kubernetes 会创建四个初始命名空间：
**default**默认的命名空间，不可删除，未指定命名空间的对象都会被分配到default中。**kube-system**Kubernetes 系统对象(控制平面和Node组件)所使用的命名空间。**kube-public**自动创建的公共命名空间，所有用户（包括未经过身份验证的用户）都可以读取它。通常我们约定，将整个集群中公用的可见和可读的资源放在这个空间中。**kube-node-lease**租约（Lease）对象使用的命名空间。每个节点都有一个关联的 lease 对象，lease 是一种轻量级资源。lease对象通过发送心跳，检测集群中的每个节点是否发生故障。
使用命名空间
命名空间是在多个用户之间划分集群资源的一种方法（通过资源配额）。
例如我们可以设置开发、测试、生产等多个命名空间。
不必使用多个命名空间来分隔轻微不同的资源。
例如同一软件的不同版本： 应该使用标签 来区分同一命名空间中的不同资源。
命名空间适用于跨多个团队或项目的场景。
对于只有几到几十个用户的集群，可以不用创建命名空间。
命名空间不能相互嵌套，每个 Kubernetes 资源只能在一个命名空间中。
[root@k8s-master ~]# kubectl get namespace
NAME STATUS AGE
kube-system Active 5d2h
default Active 5d2h
kube-public Active 5d2h
kube-node-lease Active 5d2h
[root@k8s-master ~]# kubectl get pod -A
NAMESPACE NAME READY STATUS RESTARTS AGE
kube-system local-path-provisioner-5b5579c644-fkld2 1/1 Running 1 (7h4m ago) 5d2h
kube-system svclb-traefik-d5e6bea7-n2h4m 2/2 Running 2 (7h4m ago) 5d2h
kube-system traefik-7d647b7597-jkjht 1/1 Running 1 (7h4m ago) 5d2h
default nginx-deploy-855866bb46-9xf98 1/1 Running 0 160m
kube-system svclb-traefik-d5e6bea7-j9pfd 2/2 Running 2 (7h4m ago) 5d2h
kube-system svclb-traefik-d5e6bea7-pkvcq 2/2 Running 3 (7h3m ago) 5d2h
kube-system metrics-server-74474969b-qhr2l 1/1 Terminating 1 (7h4m ago) 5d2h
default nginx-deploy-855866bb46-kfq2x 1/1 Terminating 0 160m
kube-system coredns-75fc8f8fff-bmtfn 1/1 Terminating 1 (7h4m ago) 5d2h
kube-system coredns-75fc8f8fff-56mdr 0/1 Running 0 30m
default nginx-deploy-855866bb46-zzqwb 1/1 Running 0 30m
default nginx-deploy-855866bb46-4h5jn 1/1 Terminating 0 160m
default nginx-deploy-855866bb46-sv44f 1/1 Running 0 30m
kube-system metrics-server-74474969b-qbrg7 0/1 CrashLoopBackOff 9 (4m34s ago) 30m
[root@k8s-master ~]# kubectl get lease -A
NAMESPACE NAME HOLDER AGE
kube-node-lease k8s-work1 k8s-work1 5d2h
kube-node-lease k8s-work2 k8s-work2 5d2h
kube-node-lease k8s-master k8s-master 5d2h
#创建命名空间
kubectl create namespace dev
[root@k8s-master ~]# kubectl create ns develop
namespace/develop created
#查看命名空间
kubectl get ns
#在命名空间内运行Pod
kubectl run nginx --image=nginx --namespace=dev
kubectl run my-nginx --image=nginx -n=dev
[root@k8s-master ~]# kubectl run nginx --image=nginx:1.22 -n=develop
pod/nginx created
#查看命名空间内的Pod
kubectl get pods -n=dev
[root@k8s-master ~]# kubectl get pod -n=develop
NAME READY STATUS RESTARTS AGE
nginx 1/1 Running 0 44s
# 默认查看default
[root@k8s-master ~]# kubectl get pod
NAME READY STATUS RESTARTS AGE
nginx-deploy-855866bb46-9xf98 1/1 Running 0 177m
nginx-deploy-855866bb46-kfq2x 1/1 Terminating 0 177m
nginx-deploy-855866bb46-zzqwb 1/1 Running 0 48m
nginx-deploy-855866bb46-4h5jn 1/1 Terminating 0 177m
nginx-deploy-855866bb46-sv44f 1/1 Running 0 48m
#查看当前上下文
kubectl config current-context
# 修改默认命名空间
[root@k8s-master ~]# kubectl config set-context $(kubectl config current-context) --namespace=develop
Context "default" modified.
[root@k8s-master ~]# kubectl get pod
NAME READY STATUS RESTARTS AGE
nginx 1/1 Running 0 12m
#查看命名空间内所有对象
kubectl get all
# 删除命名空间会删除命名空间下的所有内容
kubectl delete ns dev
声明式配置
常用命令缩写
YAML规范
案例：
配置对象
参考文档：Pod | Kubernetes
[root@k8s-master home]# vim my-pod.yaml
[root@k8s-master home]# kubectl apply -f my-pod.yaml
pod/nginx created
[root@k8s-master home]# kubectl get pod
NAME READY STATUS RESTARTS AGE
nginx-deploy-855866bb46-9xf98 1/1 Running 0 18h
nginx-deploy-855866bb46-zzqwb 1/1 Running 0 16h
nginx-deploy-855866bb46-sv44f 1/1 Running 0 16h
nginx 1/1 Running 0 22s
[root@k8s-master home]# kubectl delete -f my-pod.yaml
pod "nginx" deleted
#创建对象
kubectl apply -f my-pod.yaml
#编辑对象
kubectl edit nginx
#删除对象
kubectl delete -f my-pod.yaml
my-pod.yaml:
apiVersion: v1
kind: Pod
metadata:
name: nginx
spec:
containers:
- name: nginx
image: nginx:1.22
ports:
- containerPort: 80
标签
标签（Labels） 是附加到对象（比如 Pod）上的键值对，用于补充对象的描述信息。
标签使用户能够以松散的方式管理对象映射，而无需客户端存储这些映射。
由于一个集群中可能管理成千上万个容器，我们可以使用标签高效的进行选择和操作容器集合。
键的格式：
- 前缀(可选)/名称(必须)。
有效名称和值：
必须为 63 个字符或更少（可以为空）
如果不为空，必须以字母数字字符（[a-z0-9A-Z]）开头和结尾
包含破折号
**-**、下划线**_**、点**.**和字母或数字
label-pod.yaml:
apiVersion: v1
kind: Pod
metadata:
name: label-demo
labels: #定义Pod标签
environment: test
app: nginx
spec:
containers:
- name: nginx
image: nginx:1.22
ports:
- containerPort: 80
[root@k8s-master home]# vim label-pod.yaml
[root@k8s-master home]# kubectl apply -f label-pod.yaml
pod/label-demo created
[root@k8s-master home]# kubectl get pod
NAME READY STATUS RESTARTS AGE
nginx-deploy-855866bb46-9xf98 1/1 Running 0 18h
nginx-deploy-855866bb46-kfq2x 1/1 Terminating 0 18h
nginx-deploy-855866bb46-zzqwb 1/1 Running 0 16h
nginx-deploy-855866bb46-4h5jn 1/1 Terminating 0 18h
nginx-deploy-855866bb46-sv44f 1/1 Running 0 16h
label-demo 1/1 Running 0 12s
[root@k8s-master home]# kubectl get pod --show-labels
NAME READY STATUS RESTARTS AGE LABELS
nginx-deploy-855866bb46-9xf98 1/1 Running 0 18h app=nginx-deploy,pod-template-hash=855866bb46
nginx-deploy-855866bb46-kfq2x 1/1 Terminating 0 18h app=nginx-deploy,pod-template-hash=855866bb46
nginx-deploy-855866bb46-zzqwb 1/1 Running 0 16h app=nginx-deploy,pod-template-hash=855866bb46
nginx-deploy-855866bb46-4h5jn 1/1 Terminating 0 18h app=nginx-deploy,pod-template-hash=855866bb46
nginx-deploy-855866bb46-sv44f 1/1 Running 0 16h app=nginx-deploy,pod-template-hash=855866bb46
label-demo 1/1 Running 0 33s app=nginx,environment=test
[root@k8s-master home]# kubectl get pod -l "app=nginx"
NAME READY STATUS RESTARTS AGE
label-demo 1/1 Running 0 60s
[root@k8s-master home]# kubectl get pod -l "app=nginx,environment=test"
NAME READY STATUS RESTARTS AGE
label-demo 1/1 Running 0 108s
选择器
标签选择器 可以识别一组对象。标签不支持唯一性。
标签选择器最常见的用法是为Service选择一组Pod作为后端。
Service配置模板:
apiVersion: v1
kind: Service
metadata:
name: my-service
spec:
type: NodePort
selector: #与Pod的标签一致
environment: test
app: nginx
ports:
# 默认情况下，为了方便起见，`targetPort` 被设置为与 `port` 字段相同的值。
- port: 80
targetPort: 80
# 可选字段
# 默认情况下，为了方便起见，Kubernetes 控制平面会从某个范围内分配一个端口号（默认：30000-32767）
nodePort: 30007
实操：
[root@k8s-master home]# vim my-service.yaml
[root@k8s-master home]# kubectl apply -f my-service.yaml
service/my-service created
[root@k8s-master home]# kubectl get svc
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
kubernetes ClusterIP 10.43.0.1 <none> 443/TCP 5d18h
nginx-service ClusterIP 10.43.177.31 <none> 8080/TCP 18h
nginx-outside NodePort 10.43.184.94 <none> 8081:32759/TCP 17h
my-service NodePort 10.43.203.191 <none> 80:30007/TCP 58s
[root@k8s-master home]# kubectl describe svc/my-service
Name: my-service
Namespace: default
Labels: <none>
Annotations: <none>
Selector: app=nginx,environment=test
Type: NodePort
IP Family Policy: SingleStack
IP Families: IPv4
IP: 10.43.203.191
IPs: 10.43.203.191
Port: <unset> 80/TCP
TargetPort: 80/TCP
NodePort: <unset> 30007/TCP
Endpoints: 10.42.1.19:80
Session Affinity: None
External Traffic Policy: Cluster
Events: <none>
[root@k8s-master home]# kubectl get pod -l "app=nginx" -owide
NAME READY STATUS RESTARTS AGE IP NODE NOMINATED NODE READINESS GATES
label-demo 1/1 Running 0 20m 10.42.1.19 k8s-master <none> <none>
标签选择运算
目前支持两种类型的选择运算：基于等值的和基于集合的。
多个选择条件使用逗号分隔，相当于*And(***&&****)**运算。
等值选择
selector: matchLabels: # component=redis && version=7.0 component: redis version: 7.0集合选择
selector: matchExpressions: # tier in (cache, backend) && environment not in (dev, prod) - {key: tier, operator: In, values: [cache, backend]} - {key: environment, operator: NotIn, values: [dev, prod]}
容器运行时与镜像导出
准备镜像
[root@k8s-master home]# docker pull alpine:3.15
3.15: Pulling from library/alpine
d078792c4f91: Pull complete
Digest: sha256:19b4bcc4f60e99dd5ebdca0cbce22c503bbcff197549d7e19dab4f22254dc864
Status: Downloaded newer image for alpine:3.15
docker.io/library/alpine:3.15
[root@k8s-master home]# docker save alpine:3.15 > alpine-3.15.tar
[root@k8s-master home]# ls -lh
total 166M
-rw-r--r--. 1 root root 5.7M May 13 19:44 alpine-3.15.tar
-rwxrwxrwx. 1 root root 35K May 8 00:18 install.sh
-rw-rw-rw-. 1 root root 160M May 7 20:45 k3s-airgap-images-amd64.tar.gz
-rw-r--r--. 1 root root 211 May 13 18:37 label-pod.yaml
drwx------. 15 master master 4.0K May 13 02:04 master
-rw-r--r--. 1 root root 143 May 13 18:22 my-pod.yaml
-rw-r--r--. 1 root root 217 May 13 18:53 my-service.yaml
导入镜像
-n k8s.io：导入到 k8s.io 命名空间下
[root@k8s-master home]# crictl images
IMAGE TAG IMAGE ID SIZE
docker.io/library/nginx 1.22 0f8498f13f3ad 57MB
docker.io/library/nginx 1.23 a7be6198544f0 57MB
docker.io/rancher/klipper-helm v0.7.3-build20220613 38b3b9ad736af 239MB
docker.io/rancher/klipper-lb v0.3.5 dbd43b6716a08 8.51MB
docker.io/rancher/local-path-provisioner v0.0.21 fb9b574e03c34 35.3MB
docker.io/rancher/mirrored-coredns-coredns 1.9.1 99376d8f35e0a 49.7MB
docker.io/rancher/mirrored-library-busybox 1.34.1 c98db043bed91 1.47MB
docker.io/rancher/mirrored-library-traefik 2.6.2 72463d8000a35 103MB
docker.io/rancher/mirrored-metrics-server v0.5.2 f73640fb50619 65.7MB
docker.io/rancher/mirrored-pause 3.6 6270bb605e12e 686kB
[root@k8s-master home]# ctr -n k8s.io images import alpine-3.15.tar --platform linux/amd64
unpacking docker.io/library/alpine:3.15 (sha256:f85c40d9246ab4ff746abe8314c8c22d9720241bcf2244cabca3f66590a5fdd0)...done
[root@k8s-master home]# crictl images
IMAGE TAG IMAGE ID SIZE
docker.io/library/alpine 3.15 32b91e3161c8f 5.88MB
docker.io/library/nginx 1.22 0f8498f13f3ad 57MB
docker.io/library/nginx 1.23 a7be6198544f0 57MB
docker.io/rancher/klipper-helm v0.7.3-build20220613 38b3b9ad736af 239MB
docker.io/rancher/klipper-lb v0.3.5 dbd43b6716a08 8.51MB
docker.io/rancher/local-path-provisioner v0.0.21 fb9b574e03c34 35.3MB
docker.io/rancher/mirrored-coredns-coredns 1.9.1 99376d8f35e0a 49.7MB
docker.io/rancher/mirrored-library-busybox 1.34.1 c98db043bed91 1.47MB
docker.io/rancher/mirrored-library-traefik 2.6.2 72463d8000a35 103MB
docker.io/rancher/mirrored-metrics-server v0.5.2 f73640fb50619 65.7MB
docker.io/rancher/mirrored-pause 3.6 6270bb605e12e 686kB
导出镜像
[root@k8s-master home]# ctr -n k8s.io images export alpine.tar docker.io/library/alpine:3.15 --platform linux/amd64
[root@k8s-master home]# ls -lh
total 171M
-rw-r--r--. 1 root root 5.7M May 13 19:44 alpine-3.15.tar
-rw-r--r--. 1 root root 5.7M May 13 20:01 alpine.tar
-rwxrwxrwx. 1 root root 35K May 8 00:18 install.sh
-rw-rw-rw-. 1 root root 160M May 7 20:45 k3s-airgap-images-amd64.tar.gz
-rw-r--r--. 1 root root 211 May 13 18:37 label-pod.yaml
drwx------. 15 master master 4.0K May 13 02:04 master
-rw-r--r--. 1 root root 143 May 13 18:22 my-pod.yaml
-rw-r--r--. 1 root root 217 May 13 18:53 my-service.yaml
[root@k8s-master home]# scp alpine.tar root@192.168.31.180:~
root@192.168.31.180's password:
alpine.tar
[root@k8s-work1 ~]# ls -lh
total 5.7M
-rw-r--r--. 1 root root 5.7M May 13 20:28 alpine.tar
-rw-------. 1 root root 2.8K May 8 00:08 anaconda-ks.cfg
-rw-------. 1 root root 2.1K May 8 00:08 original-ks.cfg
[root@k8s-work1 ~]# ctr -n k8s.io images import alpine.tar --platform linux/amd64
unpacking docker.io/library/alpine:3.15 (sha256:f85c40d9246ab4ff746abe8314c8c22d9720241bcf2244cabca3f66590a5fdd0)...done
[root@k8s-work1 ~]# crictl images
IMAGE TAG IMAGE ID SIZE
docker.io/library/alpine 3.15 32b91e3161c8f 5.88MB
docker.io/library/nginx 1.22 0f8498f13f3ad 57MB
docker.io/library/nginx 1.23 a7be6198544f0 57MB
docker.io/rancher/klipper-helm v0.7.3-build20220613 38b3b9ad736af 239MB
docker.io/rancher/klipper-lb v0.3.5 dbd43b6716a08 8.51MB
docker.io/rancher/local-path-provisioner v0.0.21 fb9b574e03c34 35.3MB
docker.io/rancher/mirrored-coredns-coredns 1.9.1 99376d8f35e0a 49.7MB
docker.io/rancher/mirrored-library-busybox 1.34.1 c98db043bed91 1.47MB
docker.io/rancher/mirrored-library-traefik 2.6.2 72463d8000a35 103MB
docker.io/rancher/mirrored-metrics-server v0.5.2 f73640fb50619 65.7MB
docker.io/rancher/mirrored-pause 3.6 6270bb605e12e 686kB
金丝雀发布
**金丝雀部署(canary deployment)**也被称为灰度发布。
早期，工人下矿井之前会放入一只金丝雀检测井下是否存在有毒气体。
采用金丝雀部署，你可以在生产环境的基础设施中小范围的部署新的应用代码。
一旦应用签署发布，只有少数用户被路由到它，最大限度的降低影响。
如果没有错误发生，则将新版本逐渐推广到整个基础设施。
部署过程
部署第一个版本
发布v1版本的应用，镜像使用nginx:1.22,数量为 3。
deploy-v1.yaml:
apiVersion: v1
kind: Namespace
metadata:
name: dev
--- # 配置多个对象需要用---分割
apiVersion: apps/v1
kind: Deployment
metadata:
name: nginx-deployment-v1
namespace: dev
labels:
app: nginx-deployment-v1
spec:
replicas: 3
selector:
matchLabels: # 跟template.metadata.labels一致
app: nginx
template:
metadata:
labels:
app: nginx
spec:
containers:
- name: nginx
image: nginx:1.22
ports:
- containerPort: 80
--- # 配置多个对象需要用---分割
apiVersion: v1
kind: Service
metadata:
name: canary-demo
namespace: dev
spec:
type: NodePort
selector: # 更Deployment中的selector一致
app: nginx
ports:
# By default and for convenience, the `targetPort` is set to the same value as the `port` field.
- port: 80
targetPort: 80
# Optional field
# By default and for convenience, the Kubernetes control plane will allocate a port from a range (default: 30000-32767)
nodePort: 30008
执行
[root@k8s-master canary-demo]# kubectl apply -f deploy-v1.yaml
namespace/dev created
deployment.apps/nginx-deployment-v1 created
service/canary-demo created
[root@k8s-master canary-demo]# kubectl get all -n=dev
NAME READY STATUS RESTARTS AGE
pod/nginx-deployment-v1-645549fcf7-2x5xw 1/1 Running 0 130m
pod/nginx-deployment-v1-645549fcf7-cfwfk 1/1 Running 0 130m
pod/nginx-deployment-v1-645549fcf7-wph5c 1/1 Running 0 130m
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
service/canary-demo NodePort 10.43.129.224 <none> 80:30008/TCP 130m
NAME READY UP-TO-DATE AVAILABLE AGE
deployment.apps/nginx-deployment-v1 3/3 3 3 130m
NAME DESIRED CURRENT READY AGE
replicaset.apps/nginx-deployment-v1-645549fcf7 3 3 3 130m
[root@k8s-master canary-demo]# curl 10.43.129.224:80
<!DOCTYPE html>
<html>
<head>
<title>Welcome to nginx!</title>
<style>
html { color-scheme: light dark; }
body { width: 35em; margin: 0 auto;
font-family: Tahoma, Verdana, Arial, sans-serif; }
</style>
</head>
<body>
<h1>Welcome to nginx!</h1>
<p>If you see this page, the nginx web server is successfully installed and
working. Further configuration is required.</p>
<p>For online documentation and support please refer to
<a href="http://nginx.org/">nginx.org</a>.<br/>
Commercial support is available at
<a href="http://nginx.com/">nginx.com</a>.</p>
<p><em>Thank you for using nginx.</em></p>
</body>
</html>
[root@k8s-master canary-demo]# kubectl describe service canary-demo -n=dev
Name: canary-demo
Namespace: dev
Labels: <none>
Annotations: <none>
Selector: app=nginx
Type: NodePort
IP Family Policy: SingleStack
IP Families: IPv4
IP: 10.43.129.224
IPs: 10.43.129.224
Port: <unset> 80/TCP
TargetPort: 80/TCP
NodePort: <unset> 30008/TCP
Endpoints: 10.42.1.20:80,10.42.1.21:80,10.42.1.22:80
Session Affinity: None
External Traffic Policy: Cluster
Events: <none>
创建Canary Deployment
发布新版本的应用，镜像使用docker/getting-started，数量为 1。
apiVersion: apps/v1
kind: Deployment
metadata:
name: nginx-deployment-canary
namespace: dev
labels:
app: nginx-deployment-canary
spec:
replicas: 1
selector:
matchLabels: # 跟template.metadata.labels一致
app: nginx
template:
metadata:
labels:
app: nginx # 标签一直会自动加入到service中
track: canary
spec:
containers:
- name: new-nginx
image: docker/getting-started
ports:
- containerPort: 80
执行
[root@k8s-master canary-demo]# kubectl apply -f deploy-canary.yaml
deployment.apps/nginx-deployment-canary created
[root@k8s-master canary-demo]# kubectl get all -n=dev
NAME READY STATUS RESTARTS AGE
pod/nginx-deployment-v1-645549fcf7-2x5xw 1/1 Running 0 144m
pod/nginx-deployment-v1-645549fcf7-cfwfk 1/1 Running 0 144m
pod/nginx-deployment-v1-645549fcf7-wph5c 1/1 Running 0 144m
pod/nginx-deployment-canary-74577469b5-fxdkz 1/1 Running 0 58s
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
service/canary-demo NodePort 10.43.129.224 <none> 80:30008/TCP 144m
NAME READY UP-TO-DATE AVAILABLE AGE
deployment.apps/nginx-deployment-v1 3/3 3 3 144m
deployment.apps/nginx-deployment-canary 1/1 1 1 58s
NAME DESIRED CURRENT READY AGE
replicaset.apps/nginx-deployment-v1-645549fcf7 3 3 3 144m
replicaset.apps/nginx-deployment-canary-74577469b5 1 1 1 58s
调整比例
[root@k8s-master canary-demo]# kubectl scale deploy nginx-deployment-canary --replica3 -n=dev
deployment.apps/nginx-deployment-canary scaled
[root@k8s-master canary-demo]# kubectl get all -n=dev
NAME READY STATUS RESTARTS AGE
pod/nginx-deployment-v1-645549fcf7-2x5xw 1/1 Running 0 152m
pod/nginx-deployment-v1-645549fcf7-cfwfk 1/1 Running 0 152m
pod/nginx-deployment-v1-645549fcf7-wph5c 1/1 Running 0 152m
pod/nginx-deployment-canary-74577469b5-fxdkz 1/1 Running 0 8m36s
pod/nginx-deployment-canary-74577469b5-m65s2 1/1 Running 0 20s
pod/nginx-deployment-canary-74577469b5-lkzql 1/1 Running 0 20s
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
service/canary-demo NodePort 10.43.129.224 <none> 80:30008/TCP 152m
NAME READY UP-TO-DATE AVAILABLE AGE
deployment.apps/nginx-deployment-v1 3/3 3 3 152m
deployment.apps/nginx-deployment-canary 3/3 3 3 8m36s
NAME DESIRED CURRENT READY AGE
replicaset.apps/nginx-deployment-v1-645549fcf7 3 3 3 152m
replicaset.apps/nginx-deployment-canary-74577469b5 3 3 3 8m36s
[root@k8s-master canary-demo]#
下线旧版本
[root@k8s-master canary-demo]# kubectl scale deploy nginx-deployment-v1 --replicas=0 -n=dev
deployment.apps/nginx-deployment-v1 scaled
[root@k8s-master canary-demo]# kubectl get all -n=dev
NAME READY STATUS RESTARTS AGE
pod/nginx-deployment-canary-74577469b5-fxdkz 1/1 Running 0 15m
pod/nginx-deployment-canary-74577469b5-m65s2 1/1 Running 0 7m32s
pod/nginx-deployment-canary-74577469b5-lkzql 1/1 Running 0 7m32s
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
service/canary-demo NodePort 10.43.129.224 <none> 80:30008/TCP 159m
NAME READY UP-TO-DATE AVAILABLE AGE
deployment.apps/nginx-deployment-canary 3/3 3 3 15m
deployment.apps/nginx-deployment-v1 0/0 0 0 159m
NAME DESIRED CURRENT READY AGE
replicaset.apps/nginx-deployment-canary-74577469b5 3 3 3 15m
replicaset.apps/nginx-deployment-v1-645549fcf7 0 0 0 159m
清空环境
kubectl delete all --all -n=dev
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