DockerCompose 项目练习－java 微服务

docker-compose 测试 java 微服务

一、编写项目微服务

• HelloController.java 文件

package com.example.demo;

import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

@RestController
public class HelloController {
    @RequestMapping("/hello")
    public String hello() {
        return "docker Spring Boot!--微服务测试";
    }
}

• application.properties 文件

server.port = 8080
spring.redis.host = redis        # 用服务名称代替IP地址，避免IP变化，不能连接

二、创建 dockerfile 文件，构建镜像

FROM openjdk:17-ea-jdk-oraclelinux8        # 基本环境，jdk版本不能低于编译环境
COPY *.jar /app.jar        # 将当前目录的jar包拷贝到容器 /app.jar 中
CMD ["--server.port=8080"]        # 指定端口  启动
EXPOSE 8080        # 暴露的端口
ENTRYPOINT ["java","-jar","/app.jar"]        # 运行 java 程序

三、创建 docker-compose.yml 文件

version: '3.9'
services:
  webapp:        # 自定义服务名称
    build: .        # 构建镜像 
    image: webapp        # 自定义镜像名称
    depends_on:        # 启动顺序
      - redis
    ports:
      - "8080:8080"
  redis:        # redis 服务（名称可自定义），上文中的 spring.redis.host = redis 做连接
    image: redis:alpine

四、在服务器启动微服务

1、项目打包（.jar）

2、在 linux 中创建一个文件夹

[root@VM-0-6-centos home]# mkdir docker_java
[root@VM-0-6-centos home]# cd docker_java
[root@VM-0-6-centos docker_java]# ll
total 0
[root@VM-0-6-centos docker_java]# pwd
/home/docker_java

3、上传文件至服务器：.jar 、 Dockerfile 、 docker-compose.yml

4、启动 docker-compose up -d

[root@VM-0-6-centos docker_java]# docker-compose up -d
Creating network "docker_java_default" with the default driver
Pulling redis (redis:alpine)...
alpine: Pulling from library/redis
5843afab3874: Pull complete
9db2305878ef: Pull complete
3558750a1d54: Pull complete
240d71d1acc7: Pull complete
2a888d25337f: Pull complete
22e6fbce362a: Pull complete
Digest: sha256:442fbfdeccf203c277827cfd8e7e727ce411611e1a6caeda9cca8115ed17b9cc
Status: Downloaded newer image for redis:alpine
Building webapp
Sending build context to Docker daemon  17.33MB
Step 1/5 : FROM openjdk:17-ea-jdk-oraclelinux8
17-ea-jdk-oraclelinux8: Pulling from library/openjdk
c828c776e142: Pull complete 
8846dac42cae: Pull complete 
f431879d4af7: Pull complete 
Digest: sha256:cd8d4a275b8a524215da59c0f5b0ff373999cad236e24cde30f842d74eea66a9
Status: Downloaded newer image for openjdk:17-ea-jdk-oraclelinux8
 ---> 9901faf47b8c
Step 2/5 : COPY *.jar /app.jar
 ---> f88861ab682f
Step 3/5 : CMD ["--server.port=8080"]
 ---> Running in 9827a9270b4b
Removing intermediate container 9827a9270b4b
 ---> 16556550966c
Step 4/5 : EXPOSE 8080
 ---> Running in 7229bfba148b
Removing intermediate container 7229bfba148b
 ---> 82e0b5e56013
Step 5/5 : ENTRYPOINT ["java","-jar","/app.jar"]
 ---> Running in e4d32bf080f8
Removing intermediate container e4d32bf080f8
 ---> ca41a6e6bb60
Successfully built ca41a6e6bb60
Successfully tagged docker_java_webapp:latest
WARNING: Image for service webapp was built because it did not already exist. To rebuild this image you must use `docker-compose build` or `docker-compose up --build`.
# 告警，提示需要重新打包 `docker-compose build` or `docker-compose up --build`
Creating docker_java_redis_1 ... done
Creating docker_java_webapp_1 ... done

5、项目重新部署打包

• 停止运行的项目 docker-compose down

[root@VM-0-6-centos docker_java]# docker-compose down
Stopping docker_java_webapp_1 ... done
Stopping docker_java_redis_1  ... done

• 重新构建并启动
  docker-compose build 重新构建
  docker-compose up --build 重新构建，并启动！

[root@VM-0-6-centos docker_java]# docker-compose up --build -d
Building webapp
Sending build context to Docker daemon  17.33MB
Step 1/5 : FROM openjdk:17-ea-jdk-oraclelinux8
 ---> 9901faf47b8c
Step 2/5 : COPY *.jar /app.jar
 ---> Using cache
 ---> f88861ab682f
Step 3/5 : CMD ["--server.port=8080"]
 ---> Using cache
 ---> 16556550966c
Step 4/5 : EXPOSE 8080
 ---> Using cache
 ---> 82e0b5e56013
Step 5/5 : ENTRYPOINT ["java","-jar","/app.jar"]
 ---> Using cache
 ---> ca41a6e6bb60
Successfully built ca41a6e6bb60
Successfully tagged docker_java_webapp:latest
Starting docker_java_redis_1 ... done
Starting docker_java_webapp_1 ... done

6、访问测试 curl ip:端口

[root@VM-0-6-centos docker_java]# curl localhost:8080/hello
docker Spring Boot!--微服务测试[root@VM-0-6-centos docker_java]# 

• 浏览器中测试