06 k8s部署java应用 简易版本

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项目迁移至K8S流程

  1. 制作镜像
  2. 控制器管理POD
  3. 暴露应用
  4. 对外发布
  5. 日志监控

制作镜像

获取 javademo

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1. 安装Git
[root@k8s-master2 opt]# yum install git

2. 下载项目
[root@k8s-master2 opt]# cd /opt/
[root@k8s-master2 opt]# git clone https://github.com/lizhenliang/tomcat-java-demo.git

[root@k8s-master2 tomcat-java-demo]# ls -l
total 32
drwxr-xr-x 2 root root  4096 Nov 20 16:33 db              # 数据库sql文件
-rw-r--r-- 1 root root   148 Nov 20 16:33 Dockerfile      # 构建镜像
-rw-r--r-- 1 root root 11357 Nov 20 16:33 LICENSE
-rw-r--r-- 1 root root  1930 Nov 20 16:33 pom.xml         # maven构建环境
-rw-r--r-- 1 root root   270 Nov 20 16:33 README.md
drwxr-xr-x 3 root root  4096 Nov 20 16:33 src             # 源码目录

安装 mariadb 数据库

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[root@k8s-master2 tomcat-java-demo]# yum -y install mariadb mariadb-server
[root@k8s-master2 tomcat-java-demo]# systemctl start mariadb
[root@k8s-master2 tomcat-java-demo]# systemctl enable mariadb
[root@k8s-master2 tomcat-java-demo]# mysql_secure_installation

导入sql文件

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[root@k8s-master2 tomcat-java-demo]# mysql -uroot -p
MariaDB [(none)]> use test
Database changed
MariaDB [test]> source /opt/tomcat-java-demo/db/tables_ly_tomcat.sql

测试访问

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# 授权访问用户
MariaDB [test]> grant all on test.* to 'test'@'%' identified by '123456';
Query OK, 0 rows affected (0.00 sec)

# 在node2上测试
[root@k8s-node2 ~]# yum install mysql
[root@k8s-node2 ~]# mysql -h172.17.70.252 -utest -p

MariaDB [(none)]> use test
Reading table information for completion of table and column names
You can turn off this feature to get a quicker startup with -A

Database changed
MariaDB [test]> show tables;
+----------------+
| Tables_in_test |
+----------------+
| user           |
+----------------+
1 row in set (0.00 sec)

修改连库配置

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[root@k8s-master2 resources]# vim /opt/tomcat-java-demo/src/main/resources/application.yml 

datasource:
  url: jdbc:mysql://172.17.70.252:3306/test?characterEncoding=utf-8
  username: test
  password: 123456

编译源码

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[root@k8s-master2 tomcat-java-demo]# yum search openjdk
[root@k8s-master2 tomcat-java-demo]# yum install java-1.8.0-openjdk maven

# mvn 编译
[root@k8s-master2 tomcat-java-demo]# mvn clean package -Dmaven.test.skip=true
...
[INFO] ------------------------------------------------------------------------
[INFO] BUILD SUCCESS
[INFO] ------------------------------------------------------------------------
[INFO] Total time: 2.882s
[INFO] Finished at: Wed Nov 20 17:08:13 CST 2019
[INFO] Final Memory: 22M/95M
[INFO] ------------------------------------------------------------------------

# 查看生成的war包
[root@k8s-master2 tomcat-java-demo]# ls
db  Dockerfile  LICENSE  pom.xml  README.md  src  target
[root@k8s-master2 tomcat-java-demo]# cd target/
[root@k8s-master2 target]# ls -l *.war
-rw-r--r-- 1 root root 18265402 Nov 20 17:08 ly-simple-tomcat-0.0.1-SNAPSHOT.war

构建项目镜像

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# 引用了老师的tomcat镜像运行环境
[root@k8s-master2 tomcat-java-demo]# vim Dockerfile 

FROM lizhenliang/tomcat
LABEL maintainer www.ctnrs.com
RUN rm -rf /usr/local/tomcat/webapps/*
ADD target/*.war /usr/local/tomcat/webapps/ROOT.war

# 构建镜像
[root@k8s-master2 tomcat-java-demo]# docker build -t 172.17.70.252/project/java-demo .
[root@k8s-master2 tomcat-java-demo]# docker images
REPOSITORY                        TAG     IMAGE ID            CREATED             SIZE
172.17.70.252/project/java-demo   latest  f656fe851ad7        24 seconds ago      406M

# 推送到镜像仓库
[root@k8s-master2 tomcat-java-demo]# docker login 172.17.70.252
[root@k8s-master2 tomcat-java-demo]# docker push 172.17.70.252/project/java-demo

控制器管理 POD

deployment

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# web 无状态应用 deployment
[root@k8s-master1 opt]# mkdir -p /opt/java-demo
[root@k8s-master1 opt]# cd /opt/java-demo/

# 生成yaml文件
[root@k8s-master1 java-demo]# kubectl create deployment java-demo --help 
[root@k8s-master1 java-demo]# kubectl create deployment java-demo --image 172.17.70.252/project/java-demo:latest --dry-run -o yaml > deploy.yaml

[root@k8s-master1 java-demo]# vim deploy.yaml 

apiVersion: apps/v1
kind: Deployment
metadata:
  labels:
    app: java-demo
  name: java-demo
spec:
  replicas: 3
  selector:
    matchLabels:
      app: java-demo
  template:
    metadata:
      labels:
        app: java-demo
    spec:
      containers:
      - image: 172.17.70.252/project/java-demo:latest
        name: java-demo
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# 创建 pod 
[root@k8s-master1 java-demo]# kubectl apply -f deploy.yaml 
deployment.apps/java-demo created

[root@k8s-master1 java-demo]# kubectl get pods
NAME                         READY   STATUS    RESTARTS   AGE
java-demo-7746bb968c-4drq9   1/1     Running   0          12s
java-demo-7746bb968c-54gtv   1/1     Running   0          12s
java-demo-7746bb968c-jjtzr   1/1     Running   0          12s

# 查看日志
[root@k8s-master1 java-demo]# kubectl logs java-demo-7746bb968c-4drq9

# 删除掉一个pod 会重新创建
[root@k8s-master1 java-demo]# kubectl delete pod java-demo-7746bb968c-jjtzr
pod "java-demo-7746bb968c-jjtzr" deleted

[root@k8s-master1 java-demo]# kubectl get pods
NAME                         READY   STATUS    RESTARTS   AGE
java-demo-7746bb968c-4drq9   1/1     Running   0          2m23s
java-demo-7746bb968c-54gtv   1/1     Running   0          2m23s
java-demo-7746bb968c-s7824   1/1     Running   0          19s

service

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# service 暴露应用 
[root@k8s-master1 java-demo]# kubectl expose --help

Usage:
  kubectl expose (-f FILENAME | TYPE NAME) [--port=port] [--protocol=TCP|UDP|SCTP] [--target-port=number-or-name]
[--name=name] [--external-ip=external-ip-of-service] [--type=type] [options]

# --port=80                 service端口,集群内部使用
# --target-prot=8080        容器服务端口,tomcat是8080 
# --type=NodePort           生成随机端口,集群外部访问

[root@k8s-master1 java-demo]# kubectl expose deployment java-demo --port=80 --target-port=8080 --type=NodePort --dry-run -o yaml > svc.yaml

[root@k8s-master1 java-demo]# vim svc.yaml 

apiVersion: v1
kind: Service
metadata:
  creationTimestamp: null
  labels:
    app: java-demo
  name: java-demo
spec:
  ports:
  - port: 80
    protocol: TCP
    targetPort: 8080
  selector:
    app: java-demo
  type: NodePort
status:
  loadBalancer: {}
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# 创建 service
[root@k8s-master1 java-demo]# kubectl apply -f svc.yaml 
service/java-demo created

# 查看 
[root@k8s-master1 java-demo]# kubectl get pods,svc
NAME                             READY   STATUS    RESTARTS   AGE
pod/java-demo-7746bb968c-4drq9   1/1     Running   0          10m
pod/java-demo-7746bb968c-54gtv   1/1     Running   0          10m
pod/java-demo-7746bb968c-s7824   1/1     Running   0          8m9s

NAME                 TYPE        CLUSTER-IP   EXTERNAL-IP   PORT(S)        AGE
service/java-demo    NodePort    10.0.0.72    <none>        80:30999/TCP   15s
service/kubernetes   ClusterIP   10.0.0.1     <none>        443/TCP        7d6h

测试访问

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# nodeIP + 端口访问
http://39.106.168.181:30999/
http://39.106.100.108:30999/
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# 测试添加数据 然后 分别查看

MariaDB [test]> select * from user;
+----+--------+-----+------+
| id | name   | age | sex  |
+----+--------+-----+------+
|  1 | 小乔   |  28 | F    |
|  2 | 大乔   |  29 | M    |
+----+--------+-----+------+
2 rows in set (0.00 sec)