使用Rancher搭建Kubernetes集群
Rancher搭建Kubernetes集群
kubernetes有多种部署方式，已知的主要有kind、minikube、kubeadm、二进制包、Rancher
官网：https://kubernetes.io/zh/
中文社区: https://www.kubernetes.org.cn/
Rancher概述
Rancher是一个开源的企业级容器管理平台。使用Rancher，不必再从头搭建容器服务平台。
Rancher提供了在生产环境中使用的管理Docker和Kubernetes的全栈化容器部署与管理平台。
Rancher是K8S可视化管理工具，Rancher已经内置K8S，无需再额外安装，直接使用。
Rancher的安装
拉取镜像
docker pull rancher/rancher:v2.5.12
启动容器
docker run -p 80:80 -p 443:443 --name rancher --restart=unless-stopped --privileged -d rancher/rancher:v2.5.12
注意：Rancher 2.5.x 及之后的版本，需要添加–privileged标志变量，启用特权模式安装
Rancher的初始配置及概览
访问Rancher的主页，第一次需要设置管理员(admin)账号密码
设置Rancher的Server URL，其他Node都可以访问到的地址
进入Rancher首页，默认安装了k3s的集群
点击集群名称可以查看集群状态信息
点击仪表盘按钮，查看集群的各种Dashboard
Rancher应用部署
方式一
填写表单信息进行部署
导入YAML文件部署
方式二
1.创建Deployment对象
找到Deployments->Create-> Edit as YAML
填写deployment.yaml信息
2.创建Service暴露端口信息
填写service.yaml信息
Rancher部署MySQL应用
创建Deployment
# API版本
apiVersion: apps/v1
# API对象类型
kind: Deployment
metadata:
# 指定Deployment的名称
name: mysql-deployment
# 指定Deployment的空间,否则会无法创建
namespace: default
# 指定Deployment的标签
labels:
app: mysql
spec:
# 指定创建的Pod副本数量
replicas: 1
# 定义如何查找要管理的Pod
selector:
# 管理标签app为mysql的Pod
matchLabels:
app: mysql
# 指定创建Pod的模板
template:
metadata:
# 给Pod打上app:mysql标签
labels:
app: mysql
# Pod的模板规约
spec:
containers:
- name: mysql
# 指定容器镜像
image: mysql:5.7
# 指定开放的端口
ports:
- containerPort: 3306
# 设置环境变量
env:
- name: MYSQL_ROOT_PASSWORD
value: root123456
# 使用存储卷
volumeMounts:
# 将存储卷挂载到容器内部路径
- mountPath: /var/log/mysql
name: log-volume
- mountPath: /var/lib/mysql
name: data-volume
- mountPath: /etc/mysql
name: conf-volume
# 定义存储卷
volumes:
- name: log-volume
# hostPath类型存储卷在宿主机上的路径
hostPath:
path: /usr/local/program/mysql/log
# 当目录不存在时创建
type: DirectoryOrCreate
- name: data-volume
hostPath:
path: /usr/local/program/mysql/data
type: DirectoryOrCreate
- name: conf-volume
hostPath:
path: /usr/local/program/mysql/conf
type: DirectoryOrCreate
创建Service
apiVersion: v1
kind: Service
metadata:
# 定义空间
namespace: default
# 定义服务名称，其他Pod可以通过服务名称作为域名进行访问
name: mysql-service
spec:
# 指定服务类型，通过Node上的静态端口暴露服务
type: NodePort
# 管理标签app为mysql的Pod
selector:
app: mysql
ports:
- name: http
protocol: TCP
port: 3307
targetPort: 3306
# Node上的静态端口
nodePort: 30303
访问测试
获取Rancher容器IP地址
[root@administrator ~]# docker inspect rancher |grep IPAddress
"SecondaryIPAddresses": null,
"IPAddress": "172.17.0.2",
"IPAddress": "172.17.0.2",
连接数据库
[root@administrator ~]# mysql -h 172.17.0.2 -P 30303 -uroot -proot123456
mysql: [Warning] Using a password on the command line interface can be insecure.
Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 3
Server version: 5.7.37 MySQL Community Server (GPL)
Copyright (c) 2000, 2021, Oracle and/or its affiliates.
Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.
Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.
mysql>
Rancher部署SpringBoot应用
创建Deployment
apiVersion: apps/v1
kind: Deployment
metadata:
namespace: default
name: jar-deployment
labels:
app: jar-test
spec:
replicas: 1
selector:
matchLabels:
app: jar-test
template:
metadata:
labels:
app: jar-test
spec:
containers:
- name: jar-name
# 指定Docker Hub中的镜像地址
image: IP/jar-test:0.0.1-SNAPSHOT
ports:
- containerPort: 8080
env:
# 指定数据库连接地址
- name: spring.datasource.url
value: jdbc:mysql://mysql-service:3307/demo?useUnicode=true&characterEncoding=utf-8&serverTimezone=Asia/Shanghai
- name: logging.path
value: /var/logs
volumeMounts:
- mountPath: /var/logs
name: log-volume
volumes:
- name: log-volume
hostPath:
path: /usr/local/program/app/logs
type: DirectoryOrCreate
创建Service
apiVersion: v1
kind: Service
metadata:
namespace: default
name: jar-service
spec:
type: NodePort
selector:
app: jar-test
ports:
- name: http
protocol: TCP
port: 8080
targetPort: 8080
# Node上的静态端口
nodePort: 30001
访问测试
curl http://172.17.0.2:30001index.html
添加集群
在master节点运行命令导入rancher
Kubernetes基本操作
应用部署
创建一个名称为nginx-test的Deployment，同时指定应用镜像
kubectl create deployment nginx-test --image=nginx
查看所有Deployment：kubectl get deployments
NAME READY UP-TO-DATE AVAILABLE AGE
nginx-test 1/1 1 1 18s
删除部署应用
kubectl delete deployment nginx-test
查看应用信息
查看所有Pod的状态：kubectl get pods
NAME READY STATUS RESTARTS AGE
nginx-test-84b478f9c5-vz7bw 1/1 Running 0 29s
查看Pod的详细状态:kubectl describe pods
Name: nginx-test-84b478f9c5-vz7bw
Namespace: default
Priority: 0
Node: minikube/192.168.49.2
Start Time: Tue, 22 Mar 2022 09:03:09 +0800
Labels: app=nginx-test
pod-template-hash=84b478f9c5
Annotations: <none>
Status: Running
IP: 172.17.0.3
IPs:
IP: 172.17.0.3
Controlled By: ReplicaSet/nginx-test-84b478f9c5
Containers:
nginx:
Container ID: docker://8f20af263a8c7dce564fa6d49943fbef4fe151aaaef24e3564e57e13787c7213
Image: nginx
Image ID: docker-pullable://nginx@sha256:e1211ac17b29b585ed1aee166a17fad63d344bc973bc63849d74c6452d549b3e
Port: <none>
Host Port: <none>
State: Running
Started: Tue, 22 Mar 2022 09:03:13 +0800
Ready: True
Restart Count: 0
Environment: <none>
Mounts:
/var/run/secrets/kubernetes.io/serviceaccount from kube-api-access-2hldl (ro)
Conditions:
Type Status
Initialized True
Ready True
ContainersReady True
PodScheduled True
Volumes:
kube-api-access-2hldl:
Type: Projected (a volume that contains injected data from multiple sources)
TokenExpirationSeconds: 3607
ConfigMapName: kube-root-ca.crt
ConfigMapOptional: <nil>
DownwardAPI: true
QoS Class: BestEffort
Node-Selectors: <none>
Tolerations: node.kubernetes.io/not-ready:NoExecute op=Exists for 300s
node.kubernetes.io/unreachable:NoExecute op=Exists for 300s
Events:
Type Reason Age From Message
---- ------ ---- ---- -------
Normal Scheduled 39s default-scheduler Successfully assigned default/nginx-test-84b478f9c5-vz7bw to minikube
Normal Pulling 39s kubelet Pulling image "nginx"
Normal Pulled 36s kubelet Successfully pulled image "nginx" in 2.952573727s
Normal Created 35s kubelet Created container nginx
Normal Started 35s kubelet Started container nginx
将Pod名称设置为环境变量，方便使用$POD_NAME来应用Pod的名称
export NGINX_POD=nginx-test-84b478f9c5-vz7bw
查看Pod打印的日志：kubectl logs $NGINX_POD
/docker-entrypoint.sh: /docker-entrypoint.d/ is not empty, will attempt to perform configuration
/docker-entrypoint.sh: Looking for shell scripts in /docker-entrypoint.d/
/docker-entrypoint.sh: Launching /docker-entrypoint.d/10-listen-on-ipv6-by-default.sh
10-listen-on-ipv6-by-default.sh: info: Getting the checksum of /etc/nginx/conf.d/default.conf
10-listen-on-ipv6-by-default.sh: info: Enabled listen on IPv6 in /etc/nginx/conf.d/default.conf
/docker-entrypoint.sh: Launching /docker-entrypoint.d/20-envsubst-on-templates.sh
/docker-entrypoint.sh: Launching /docker-entrypoint.d/30-tune-worker-processes.sh
/docker-entrypoint.sh: Configuration complete; ready for start up
2022/03/22 01:03:13 [notice] 1#1: using the "epoll" event method
2022/03/22 01:03:13 [notice] 1#1: nginx/1.21.6
2022/03/22 01:03:13 [notice] 1#1: built by gcc 10.2.1 20210110 (Debian 10.2.1-6)
2022/03/22 01:03:13 [notice] 1#1: OS: Linux 3.10.0-1160.59.1.el7.x86_64
2022/03/22 01:03:13 [notice] 1#1: getrlimit(RLIMIT_NOFILE): 1048576:1048576
2022/03/22 01:03:13 [notice] 1#1: start worker processes
2022/03/22 01:03:13 [notice] 1#1: start worker process 32
2022/03/22 01:03:13 [notice] 1#1: start worker process 33
使用exec在Pod的容器中执行命令
kubectl exec nginx-test-84b478f9c5-vz7bw -- echo hello world
进入容器内部并执行bash命令，退出容器使用exit命令
kubectl exec -it nginx-test-84b478f9c5-vz7bw -- bash
公开暴露应用
默认Pod无法被集群外部访问，需要创建Service并暴露端口才能被外部访问。
创建Service暴露nginx-test这个Deployment，通过NodePort属性得到暴露到外部的端口
kubectl expose deployment nginx-test --type=NodePort --port 80
查看所有Service的状态:kubectl get services
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
kubernetes ClusterIP 10.96.0.1 <none> 443/TCP 16h
nginx-test NodePort 10.101.176.18 <none> 80:32299/TCP 77s
查看Service的详情
kubectl describe services nginx-test
访问服务：IP：32299
Name: nginx-test
Namespace: default
Labels: app=nginx-test
Annotations: <none>
Selector: app=nginx-test
Type: NodePort
IP Family Policy: SingleStack
IP Families: IPv4
IP: 10.101.176.18
IPs: 10.101.176.18
Port: <unset> 80/TCP
TargetPort: 80/TCP
NodePort: <unset> 32299/TCP
Endpoints: 172.17.0.3:80
Session Affinity: None
External Traffic Policy: Cluster
Events: <none>
标签的使用
通过给资源添加Label，可以方便地管理资源
查看Deployment中所包含的Label：kubectl describe deployment
Name: nginx-test
Namespace: default
CreationTimestamp: Tue, 22 Mar 2022 09:03:09 +0800
Labels: app=nginx-test
Annotations: deployment.kubernetes.io/revision: 1
Selector: app=nginx-test
Replicas: 1 desired | 1 updated | 1 total | 1 available | 0 unavailable
StrategyType: RollingUpdate
MinReadySeconds: 0
RollingUpdateStrategy: 25% max unavailable, 25% max surge
Pod Template:
Labels: app=nginx-test
Containers:
nginx:
Image: nginx
Port: <none>
Host Port: <none>
Environment: <none>
Mounts: <none>
Volumes: <none>
Conditions:
Type Status Reason
---- ------ ------
Available True MinimumReplicasAvailable
Progressing True NewReplicaSetAvailable
OldReplicaSets: <none>
NewReplicaSet: nginx-test-84b478f9c5 (1/1 replicas created)
Events:
Type Reason Age From Message
---- ------ ---- ---- -------
Normal ScalingReplicaSet 32m deployment-controller Scaled up replica set nginx-test-84b478f9c5 to 1
通过Label查询Pod：kubectl get pods -l app=nginx-test
NAME READY STATUS RESTARTS AGE
nginx-test-84b478f9c5-vz7bw 1/1 Running 0 34m
通过Label查询Service：kubectl get services -l app=nginx-test
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
nginx-test NodePort 10.101.176.18 <none> 80:32299/TCP 16m
给Pod添加Label：kubectl label pod nginx-test-84b478f9c5-vz7bw env_role=dev
查看Pod的详细信息：kubectl describe pods nginx-test-84b478f9c5-vz7bw
Name: nginx-test-84b478f9c5-vz7bw
Namespace: default
Priority: 0
Node: minikube/192.168.49.2
Start Time: Tue, 22 Mar 2022 09:03:09 +0800
Labels: app=nginx-test
env_role=dev
通过Label删除服务：kubectl delete service -l app=nginx-test
service "nginx-test" deleted
kubectl get service
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
kubernetes ClusterIP 10.96.0.1 <none> 443/TCP 16h
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