第14章：部署Java网站项目案例

1 说明

(1) 项目迁移到k8s平台的流程

1) 制作镜像

dockerfile、docker+jenkins持续集成。镜像分类：基础镜像、中间镜像、项目镜像

2) 控制器管理pod

控制器管理pod，deployment(无状态应用)、deamonset(守护进程)、statsfulset(有状态应用)、job&cronjob(批处理)

3) pod数据持久化

pv、pvc

4) 暴露应用

5) 对外发布应用

service nodeport、ingress(LB -> ingress controller -> pod)

2 环境说明

主机名称	ip地址	备注
k8s_harbor	172.16.1.61	访问：http://172.16.1.61/ 用户：admin 密码：Harbor12345 项目：java(包含tomcat:v01的镜像)
k8s_gitlab	172.16.1.62	访问：http://172.16.1.62:9999/ 用户：root 密码：12345678 项目：dev/java
k8s_nfs	172.16.1.63	用于镜像构建和镜像推送和nfs

3 操作步骤

(1) 安装编译环境
1) 安装openjdk和maven
[root@k8s_nfs ~]# yum install java-1.8.0-openjdk maven -y

2) 替换maven国内源
[root@k8s_nfs ~]# vim /etc/maven/settings.xml
# 158行下面插入如下内容
    <mirror>
      <id>aliyunmaven</id>
      <mirrorOf>*</mirrorOf>
      <name>阿里云公共仓库</name>
      <url>https://maven.aliyun.com/repository/public</url>
    </mirror>

(2) 编译构建
[root@k8s_nfs ~]# git clone http://172.16.1.62:9999/dev/java.git
[root@k8s_nfs ~]# cd java/
[root@k8s_nfs java]# mvn clean package -DskipTests=true
[root@k8s_nfs java]# ls target/
classes            ly-simple-tomcat-0.0.1-SNAPSHOT      maven-archiver
generated-sources  ly-simple-tomcat-0.0.1-SNAPSHOT.war  maven-status

(3) 使用Dockerfile构建镜像并将war包推送到镜像仓库
1) 修改harbor镜像仓库认证(需要在k8s集群上也要做配置，否则无法拉取)
[root@k8s_nfs java]# cat /etc/docker/daemon.json
{
  "registry-mirrors": ["https://b1cx9cn7.mirror.aliyuncs.com"],
  "insecure-registries": ["172.16.1.61"]
}

[root@k8s_nfs java]# systemctl daemon-reload
[root@k8s_nfs java]# systemctl restart docker

2) 登录镜像仓库
[root@k8s_nfs java]# docker login 172.16.1.61

3) 将war包打入tomcat镜像
[root@k8s_nfs java]# cat Dockerfile
FROM 172.16.1.61/java/tomcat:v01
RUN rm -rf /usr/local/tomcat/webapps/*
COPY target/*.war /usr/local/tomcat/webapps/ROOT.war

[root@k8s_nfs java]# docker build -t 172.16.1.61/java/tomcat:v20 .

[root@k8s_nfs java]# docker images
REPOSITORY                TAG                 IMAGE ID            CREATED             SIZE
172.16.1.61/java/tomcat   v20                 36330bfb480e        9 seconds ago       785MB
172.16.1.61/java/tomcat   v01                 fc492f3c2b01        23 hours ago        767MB

4) 推送tomcat项目镜像到harbor仓库
[root@k8s_nfs java]# docker push 172.16.1.61/java/tomcat:v20

(4) 创建secret保存harbor认证信息
[root@k8s-admin ~]# kubectl create secret docker-registry dockerpullauth --docker-username=admin --docker-password=Harbor12345 --docker-server=172.16.1.61

(5) 编写yaml部署(deployment)
[root@k8s-admin ~]# kubectl create deployment java --image=172.16.1.61/java/tomcat:v20 --dry-run -o yaml > deplo
yment-java.yaml

[root@k8s-admin ~]# cat deployment-java.yaml
apiVersion: apps/v1
kind: Deployment
metadata:
  name: java
  labels:
    app: java
spec:
  replicas: 3
  selector:
    matchLabels:
      project: www
      app: java
  template:
    metadata:
      labels:
        project: www
        app: java
    spec:
      imagePullSecrets:
      - name: "dockerpullauth"
      restartPolicy: Always
      containers:
      - image: 172.16.1.61/java/tomcat:v20
        name: tomcat
        imagePullPolicy: IfNotPresent
        ports:
        - containerPort: 8080
          name: tomcat
          protocol: TCP
        resources:
          requests:
            cpu: 0.5
            memory: 1Gi
          limits:
            cpu: 1
            memory: 2Gi
        livenessProbe:
          httpGet:
            path: /
            port: 8080
          initialDelaySeconds: 60
          timeoutSeconds: 20
          periodSeconds: 10
        readinessProbe:
          httpGet:
            path: /
            port: 8080
          initialDelaySeconds: 60
          periodSeconds: 10
          timeoutSeconds: 20

[root@k8s-admin ~]# kubectl apply -f deployment-java.yaml
[root@k8s-admin ~]# kubectl get pod -o wide
NAME                    READY   STATUS    RESTARTS   AGE     IP            NODE        NOMINATED NODE   READINESS GATES
java-7f9c5f9d64-8n675   1/1     Running   0          9m26s   10.244.1.14   k8s-node1   <none>           <none>
java-7f9c5f9d64-tnrft   1/1     Running   0          9m26s   10.244.2.13   k8s-node2   <none>           <none>
java-7f9c5f9d64-xntk9   1/1     Running   0          9m26s   10.244.2.12   k8s-node2   <none>           <none>

(6) 编写yaml部署(service)
[root@k8s-admin ~]# kubectl expose deployment java --port=80 --target-port=8080 --type=NodePort --dry-run -o yaml > service-java.yaml

[root@k8s-admin ~]# cat service-java.yaml
apiVersion: v1
kind: Service
metadata:
  labels:
    app: java
  name: java
spec:
  ports:
  - port: 80
    protocol: TCP
    targetPort: 8080
    nodePort: 30009
  selector:
    app: java
    project: www
  type: NodePort

[root@k8s-admin ~]# kubectl apply -f service-java.yaml
[root@k8s-admin ~]# kubectl get deploy,pod,svc,ep -o wide
NAME                   READY   UP-TO-DATE   AVAILABLE   AGE   CONTAINERS   IMAGES                        SELECTOR
deployment.apps/java   3/3     3            3           30m   tomcat       172.16.1.61/java/tomcat:v20   app=java,project=www

NAME                        READY   STATUS    RESTARTS   AGE   IP            NODE
pod/java-7f9c5f9d64-8n675   1/1     Running   0          30m   10.244.1.14   k8s-node1
pod/java-7f9c5f9d64-tnrft   1/1     Running   0          30m   10.244.2.13   k8s-node2
pod/java-7f9c5f9d64-xntk9   1/1     Running   0          30m   10.244.2.12   k8s-node2

NAME                 TYPE        CLUSTER-IP     EXTERNAL-IP   PORT(S)        AGE     SELECTOR
service/java         NodePort    10.96.192.44   <none>        80:30009/TCP   2m53s   app=java,project=www
service/kubernetes   ClusterIP   10.96.0.1      <none>        443/TCP        44d     <none>

NAME                   ENDPOINTS                                            AGE
endpoints/java         10.244.1.14:8080,10.244.2.12:8080,10.244.2.13:8080   2m53s
endpoints/kubernetes   172.16.1.70:6443                                     44d

(7) 访问
http://172.16.1.71:30009/
http://172.16.1.72:30009/

(8) 创建数据库
[root@k8s_nfs ~]# docker run -d --name mysql -p 3306:3306 -e MYSQL_ROOT_PASSWORD=123456 mysql:5.7
[root@k8s_nfs ~]# docker exec -it mysql bash
root@d5503ea45b93:/# mysql -uroot -p$MYSQL_ROOT_PASSWORD
mysql> grant all on test.* to wp@'%' identified by '123456';

(9) 安装ingress-controller配置ingress.yaml模板实现对service下的pod做负载均衡，可以跳过k8s service的转发网络，直接负载service后面的pod提高效率。