单个Dockerfile合并多个镜像以及docker-compose批量部署

合并多个镜像到单个Dockerfile

FROM 后面跟上AS 生成阶段指定名称

FROM openjdk:8 AS practice-service
ARG logs=/logs
ENV TZ Asia/Shanghai
ENV address=${address} \
    port=${port} \
    namespace=${namespace} \
    logs=${logs}
COPY ./practice.jar  /opt/practice.jar
CMD ["java", "-Dfile.encoding=utf-8", "-Xms512M","-Xmx1024M","-jar", "/opt/practice.jar","--logging.file.name=${logs}/practice.log"]


FROM openjdk:8 AS case-service
ARG logs=/logs
ENV TZ Asia/Shanghai
ENV logs=${logs}
COPY ./case.jar  /opt/case.jar
CMD ["java", "-Dfile.encoding=utf-8", "-Xms512M","-Xmx1024M","-jar", "/opt/case.jar","--logging.file.name=${logs}/case.log"]

构建镜像

执行下面的命令就能同时构建两个镜像了,其中 -t 是生成的镜像名称, --target是 AS 后面生成阶段, 例如:

docker build -t practice-service:1.0.0 --target practice-service .
docker build -t case-service:1.0.0 --target case-service .

关于AS

默认情况，每个构建阶段是没有命名的，通过整型编号进行引用(类似数组下标索引，0-第一个FROM，1-第二个FROM，依次类推, 以下面的Dockefile为例, 第二个COPY: 把前构建阶段–from=0的/go/src/github.com/helloworld/app文件复制到 ./root/目录

FROM golang:1.13.5 
WORKDIR /go/src/github.com/helloworld/
# RUN go get -d -v golang.org/x/net/html  
RUN go get -d -v github.com/go-sql-driver/mysql
COPY app.go    .
RUN CGO_ENABLED=0 GOOS=linux go build -a -installsuffix cgo -o app .

FROM alpine:latest  
RUN apk --no-cache add ca-certificates
WORKDIR /root/
COPY --from=0 /go/src/github.com/helloworld/app .
CMD ["./app"]

如果存在AS阶段名的话, Dockfile里面还可以通过 --from=<阶段名> 调用

docker-compose批量构建镜像并启动

version: "3.6"
services:
  practice-service:
    build:  #build对应build镜像的操作
      context: .  #路径
      dockerfile: Dockerfile 
      target: practice-service  #对应镜像阶段
    image: practice-service:1.0.0 
    container_name: practice-service
    restart: always
    deploy:   #容器的资源限制 
      resources:
         limits:
            cpus: "2.00"
            memory: 5G
         reservations:  #初始化资源,只支持内存参数,CPU参数不支持
            memory: 200M
    volumes:
      - /home/sdp/bin/log/practice-service:/logs
      - /etc/localtime:/etc/localtime
    ports:
      - "8888:8888"
    environment:
      - TZ=Asia/Shanghai
      - logs=/logs
    logging:  # 日志大小限制
      driver: "json-file"
      options:
        max-size: "1000k"
        max-file: "20"
  case-service:
    build:
      context: .
      dockerfile: Dockerfile
      target: case-service
    image: case-service:1.0.0
    container_name: case-service
    restart: always
    volumes:
      - /home/sdp/bin/log/ase-service:/logs
      - /etc/localtime:/etc/localtime
    ports:
      - "8890:8890"
    environment:
      - TZ=Asia/Shanghai
      - logs=/logs
    logging:
      driver: "json-file"
      options:
        max-size: "1000k"
        max-file: "20"    

docker-compose的target选项是在version: "3.4"之后才支持的, 不支持该参数的话需要升级更新, 具体介绍见 https://github.com/docker/compose ,安装步骤如下

wget https://github.com/docker/compose/releases/download/v2.10.2/docker-compose-linux-x86_64
mv docker-compose-linux-x86_64 /usr/local/bin/docker-compose
chmod 755 /usr/local/bin/docker-compose
source /etc/profile

执行 docker-compose up --build -d 会在在后台启动容器并在启动前构建镜像
docker-compose start <服务名> 可以启动单个服务
docker-compose stop <服务名> 可以停止单个服务
docker-compose down --rmi all会删除所有镜像和容器

如果遇到下面的报错,可以先执行export DOCKER_BUILDKIT=0设置环境变量后再执行docker-cmpose的命令

[root@node product]# docker-compose up
[+] Running 0/2
 ⠿ practice-service Error                                                                                                                                                 2.8s
 ⠿ exam-service Error                                                                                                                                                     2.9s
[+] Building 0.0s (0/0)                                                                                                                                                        
listing workers for Build: failed to list workers: Unavailable: connection error: desc = "transport: Error while dialing unable to upgrade to h2c, received 404"

参考

1. docker-compose限制容器cpu和内存
2. Docker多阶段构建镜像
3. https://github.com/containers/podman/issues/13889