4. docker镜像、Dockerfile

一、docker镜像

1、镜像介绍

• 分层的文件系统
  优势：节省空间、速度快、重用

• 只读
  创建容器时，会在镜像上面添加一个可写层

2、镜像核心技术

• COW copy on write 写时复制
• Union fs 联合文件系统
  overlay2
  device mapper

[root@martin-host ~]# docker info  
Client: Docker Engine - Community
 Version:    26.1.4
 Context:    default
 Debug Mode: false
 Plugins:
  buildx: Docker Buildx (Docker Inc.)
    Version:  v0.14.1
    Path:     /usr/libexec/docker/cli-plugins/docker-buildx
  compose: Docker Compose (Docker Inc.)
    Version:  v2.27.1
    Path:     /usr/libexec/docker/cli-plugins/docker-compose

Server:
 Containers: 1
  Running: 0
  Paused: 0
  Stopped: 1
 Images: 4
 Server Version: 26.1.4
 Storage Driver: overlay2

二、Dockerfile定制镜像

1、Dockerfile使用流程

1.1 编写Dockerfile

[root@martin-host testDockerfile]# ls
CentOS-Base.repo  Dockerfile
[root@martin-host testDockerfile]# cat Dockerfile 
FROM centos:7

COPY  CentOS-Base.repo /etc/yum.repos.d/CentOS-Base.repo

RUN yum install -y net-tools

1.2、构建镜像

[root@martin-host testDockerfile]# docker build -t centos:v1 ./ 

1.3 创建容器测试镜像定制操作

[root@martin-host testDockerfile]# docker image ls
REPOSITORY   TAG       IMAGE ID       CREATED          SIZE
centos       v1        3e88e2fdb6df   56 seconds ago   461MB
redis        latest    7614ae9453d1   2 years ago      113MB
centos       7         eeb6ee3f44bd   2 years ago      204MB
nginx        1.18      c2c45d506085   3 years ago      133MB

[root@martin-host testDockerfile]# docker run -tid --name=test1 centos:v1 
949b757d2b35b4d115a88f69cc8f1d704b6e6fcd34a64d4ecbfc28422e7530aa

[root@martin-host testDockerfile]# docker exec -ti test1 bash
[root@949b757d2b35 /]# ifconfig
eth0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1472
        inet 10.88.7.2  netmask 255.255.255.0  broadcast 10.88.7.255
        ether 02:42:0a:58:07:02  txqueuelen 0  (Ethernet)
        RX packets 8  bytes 656 (656.0 B)

2、Dockerfile常用指令

• FROM
  指定基础镜像；
  镜像不存在，构建镜像时自动下载镜像
  建议尽量选择小容量的镜像 / debian/ ubuntu

FROM 镜像名称 

• RUN
  指定定制命令

RUN 命令 && 命令 && 命令

• CMD
  定义容器创建时，自动执行的命令
  注意事项:
  1、前台启动服务的指令
  2、创建容器时，不要自己指定命令，会覆盖CMD
  3、一个Dockerfile中只能有一条CMD指令

CMD httpd -D FOREGROUND
CMD ["httpd", "-D", "FOREGROUND"]	// 推荐

• ENTRYPOINT
  定义容器创建时，自动执行的命令
  不会被覆盖

ENTRYPOINT ["httpd", "-D", "FOREGROUND"]

• COPY
  复制文件
  注意：只能复制本地文件

COPY 源文件 目的文件 

• ADD
  复制文件
  注意：
  1、支持本地文件、URL、压缩包会自动解压

ADD 源文件 目的文件 

ADD file01 /tmp/file01
ADD http://nginx.org/download/nginx-1.27.0.tar.gz /tmp
ADD jdk-8u91-linux-x64.tar.gz /tmp

• EXPOSE
  说明容器服务端口
  注意：
  1、-P随机发布端口时，Dockerfile中必须有EXPOSE指令

EXPOSE 端口 端口

• VOLUME
  定义持久化存储的目录
  创建容器时不使用-v明确指定目录，会自动生成匿名卷

VOLUME 目录

• ENV
  定义环境变量

ENV 变量名称 值 

• WORKDIR
  定义当前目录

WORKDIR 目录

• USER
  指定容器运行的用户

USER 用户名

三、部署springcloud微服务架构的商品秒杀项目

1、部署项目需要的基础服务

1.1 部署redis缓存

[root@martin-host web]# docker run -tid --name=redis --hostname=redis --restart=always --net=host redis:3.2.10 
33ff624e19c309793fdfa23dbd5c0a88490637cd5e0090bfee7dc98c63721732

[root@martin-host web]# docker ps -a
CONTAINER ID   IMAGE          COMMAND                  CREATED         STATUS         PORTS     NAMES
33ff624e19c3   redis:3.2.10   "docker-entrypoint.s…"   5 seconds ago   Up 4 seconds             redis

[root@martin-host web]# netstat -tunlp | grep 6379
tcp        0      0 0.0.0.0:6379            0.0.0.0:*               LISTEN      2570/redis-server * 
tcp6       0      0 :::6379                 :::*                    LISTEN      2570/redis-server * 

1.2 部署MySQL数据库

[root@martin-host web]# docker run -tid --name=web_db --hostname=web_db --restart=always --net=host -e MYSQL_ROOT_PASSWORD=admin mysql:5.7
4ba7f19a4e15ef11facd18e329796dc391c0d0ce1a144fe7f67380fad65ab043
[root@martin-host web]# 
[root@martin-host web]# docker ps -a
CONTAINER ID   IMAGE          COMMAND                  CREATED              STATUS              PORTS     NAMES
4ba7f19a4e15   mysql:5.7      "docker-entrypoint.s…"   4 seconds ago        Up 3 seconds                  web_db
33ff624e19c3   redis:3.2.10   "docker-entrypoint.s…"   About a minute ago   Up About a minute             redis

[root@martin-host web]# docker cp shop_goods.sql web_db:/
Successfully copied 3.58kB to web_db:/
[root@martin-host web]# docker cp shop_member.sql web_db:/
Successfully copied 3.58kB to web_db:/
[root@martin-host web]# docker cp shop_seckill.sql web_db:/
Successfully copied 7.68kB to web_db:/
[root@martin-host web]# 
[root@martin-host web]# docker exec -ti web_db bash
root@web_db:/# 
root@web_db:/# mysql -uroot -padmin < /shop_goods.sql 
mysql: [Warning] Using a password on the command line interface can be insecure.
root@web_db:/# mysql -uroot -padmin < /shop_member.sql 
mysql: [Warning] Using a password on the command line interface can be insecure.
root@web_db:/# mysql -uroot -padmin < /shop_seckill.sql 
mysql: [Warning] Using a password on the command line interface can be insecure.
root@web_db:/# 
root@web_db:/# mysql -uroot -padmin
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 5
Server version: 5.7.35 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> 
mysql> show databases;
+--------------------+
| Database           |
+--------------------+
| information_schema |
| mysql              |
| performance_schema |
| shop_goods         |
| shop_member        |
| shop_seckill       |
| sys                |
+--------------------+
7 rows in set (0.00 sec)

mysql> 
mysql> grant all on *.* to 'root'@'%' identified by 'admin';
Query OK, 0 rows affected, 1 warning (0.00 sec)

mysql> flush privileges;
Query OK, 0 rows affected (0.00 sec)

mysql> exit
Bye
root@web_db:/# exit
exit

1.3 部署rabbitmq消息队列

[root@martin-host web]# docker run -tid --name=rabbitmq --hostname=rabbitmq --net=host rabbitmq:3-management 
d9e860cf2773cbf4c6462483fb5dabea600b00295f44f55d088f5797de0c8efa
[root@martin-host web]# 
[root@martin-host web]# docker ps -a
CONTAINER ID   IMAGE                   COMMAND                  CREATED         STATUS         PORTS     NAMES
d9e860cf2773   rabbitmq:3-management   "docker-entrypoint.s…"   3 seconds ago   Up 2 seconds             rabbitmq
4ba7f19a4e15   mysql:5.7               "docker-entrypoint.s…"   4 minutes ago   Up 4 minutes             web_db
33ff624e19c3   redis:3.2.10            "docker-entrypoint.s…"   6 minutes ago   Up 6 minutes             redis

[root@martin-host ~]# docker exec -ti rabbitmq bash

root@rabbitmq:/# rabbitmqctl add_user liushao admin
Adding user "liushao" ...
Done. Don't forget to grant the user permissions to some virtual hosts! See 'rabbitmqctl help set_permissions' to learn more.

root@rabbitmq:/# rabbitmqctl set_permissions liushao ".*" ".*" ".*"
Setting permissions for user "liushao" in vhost "/" ...
root@rabbitmq:/# 

2、部署微服务框架

2.1 部署erueka 注册中心

负责注册所有服务的通信地址

[root@martin-host web]# cat eurekaDockerfile 
FROM adoptopenjdk/openjdk8:latest

COPY eureka-server-1.0-SNAPSHOT.jar /eureka-server.jar

CMD ["java", "-jar", "/eureka-server.jar"]
[root@martin-host web]# 
[root@martin-host web]# docker build -t eureka-server:1.0 -f eurekaDockerfile ./ 

root@martin-host web]# docker run -tid --name=eureka-server --hostname=eureka-server --restart=always --net=host eureka-server:1.0 
c682585f005c0be0ffae1dba1232410f92045c0763de5393d1efaedd79a0bdb3

[root@martin-host web]# docker logs eureka-server 
2024-07-19 02:40:53.881  INFO 1 --- [           main] .s.c.n.e.s.EurekaAutoServiceRegistration : Updating port to 8761

2.2 部署config-server 配置中心

负责集中管理所有业务组件的配置文件、从远程的git服务器拉取配置文件

[root@martin-host web]# cat configDockerfile
FROM adoptopenjdk/openjdk8:latest

COPY config-server-1.0-SNAPSHOT.jar /config-server.jar

CMD ["java", "-jar", "/config-server.jar"]
[root@martin-host web]# 
[root@martin-host web]# docker build -t config-server:1.0 -f configDockerfile ./

[root@martin-host web]# docker run -tid --name=config-server --hostname=config-server --net=host --restart=always config-server:1.0 

[root@martin-host web]# docker logs config-server 
2024-07-19 02:49:37.965  INFO 1 --- [           main] .s.c.n.e.s.EurekaAutoServiceRegistration : Updating port to 9100

2.3 部署zuul-server 网关

负责集中接收处理请求、反向代理 、负载均衡

[root@martin-host web]# cat zuulDockerfile
FROM adoptopenjdk/openjdk8:latest

COPY zuul-server-1.0-SNAPSHOT.jar /zuul-server.jar

CMD ["java", "-jar", "/zuul-server.jar"]
[root@martin-host web]# 
[root@martin-host web]# docker build -t zuul-server:1.0 -f zuulDockerfile ./

[root@martin-host web]# docker run -tid --name=zuul-server --hostname=zuul-server --net=host --restart=always zuul-server:1.0 

[root@martin-host web]# docker logs zuul-server 
2024-07-19 02:56:57.602  INFO 1 --- [           main] .s.c.n.e.s.EurekaAutoServiceRegistration : Updating port to 9000

3、部署业务

3.1 部署会员服务

[root@martin-host web]# cat memberDockerfile
FROM adoptopenjdk/openjdk8:latest

COPY member-server-1.0-SNAPSHOT.jar /member-server.jar 

CMD ["java", "-jar", "/member-server.jar"]

[root@martin-host web]# docker build -t member-server:1.0 -f memberDockerfile ./

[root@martin-host web]# docker run -tid --name=member-server --hostname=localhost --net=host --restart=always member-server:1.0 

2024-07-19 03:26:42.696  INFO 1 --- [           main] .s.c.n.e.s.EurekaAutoServiceRegistration : Updating port to 8083

3.2 部署商品展示业务

[root@martin-host web]# cat goodDockerfile
FROM adoptopenjdk/openjdk8:latest

COPY good-server-1.0-SNAPSHOT.jar /good-server.jar

CMD ["java", "-jar", "/good-server.jar"]
[root@martin-host web]# 
[root@martin-host web]# docker build -t good-server:1.0 -f goodDockerfile ./

[root@martin-host web]# docker run -tid --name=good-server --hostname=localhost --net=host --restart=always good-server:1.0 

2024-07-19 03:29:49.555  INFO 1 --- [           main] .s.c.n.e.s.EurekaAutoServiceRegistration : Updating port to 8084

3.3 部署秒杀业务

[root@martin-host web]# cat seckillDockerfile
FROM adoptopenjdk/openjdk8:latest

COPY seckill-server-1.0-SNAPSHOT.jar /seckill-server.jar

CMD ["java", "-jar", "/seckill-server.jar"]
[root@martin-host web]# 
[root@martin-host web]# docker build -t seckill-server:1.0 -f seckillDockerfile ./

[root@martin-host web]# docker run -tid --name=seckill-server --hostname=localhost --net=host --restart=always seckill-server:1.0 

2024-07-19 03:32:56.665  INFO 1 --- [           main] o.s.a.r.c.CachingConnectionFactory       : Created new connection: rabbitConnectionFactory#1c6804cd:0/SimpleConnection@4fdfa676 [delegate=amqp://guest@192.168.183.10:5672/, localPort= 34446]
2024-07-19 03:32:56.851  INFO 1 --- [           main] o.s.b.w.embedded.tomcat.TomcatWebServer  : Tomcat started on port(s): 8085 (http) with context path ''
2024-07-19 03:32:56.853  INFO 1 --- [           main] .s.c.n.e.s.EurekaAutoServiceRegistration : Updating port to 8085

3.4 部署web前端

[root@martin-host web]# cat frontendDockerfile
FROM adoptopenjdk/openjdk8:latest

COPY frontend-server-0.0.1-SNAPSHOT.jar /frontend-server.jar

CMD ["java", "-jar", "/frontend-server.jar"]
[root@martin-host web]# 
[root@martin-host web]# docker build -t frontend-server:1.0 -f frontendDockerfile ./

[root@martin-host web]# docker run -tid --name=frontend-server --hostname=localhost --net=host --restart=always frontend-server:1.0 

2024-07-19 03:36:03.029  INFO 1 --- [           main] o.s.b.w.embedded.tomcat.TomcatWebServer  : Tomcat started on port(s): 8080 (http) with context path ''

3.4 部署websocket， 实现http长连接

[root@martin-host web]# cat websocketDockerfile
FROM adoptopenjdk/openjdk8:latest

COPY websocket-server-0.0.1-SNAPSHOT.jar /websocket-server.jar

CMD ["java", "-jar", "/websocket-server.jar"]
[root@martin-host web]# 
[root@martin-host web]# docker build -t websocket-server:1.0 -f websocketDockerfile ./
[+] Building 0.5s (7/7) FINISHED                                                                                       docker:default
 => [internal] load build definition from websocketDockerfile                                                                    0.0s
 => => transferring dockerfile: 193B                                                                                             0.0s
 => [internal] load metadata for docker.io/adoptopenjdk/openjdk8:latest                                                          0.0s
 => [internal] load .dockerignore                                                                                                0.0s
 => => transferring context: 2B                                                                                                  0.0s
 => [internal] load build context                                                                                                0.2s
 => => transferring context: 21.84MB                                                                                             0.2s
 => CACHED [1/2] FROM docker.io/adoptopenjdk/openjdk8:latest                                                                     0.0s
 => [2/2] COPY websocket-server-0.0.1-SNAPSHOT.jar /websocket-server.jar                                                         0.2s
 => exporting to image                                                                                                           0.1s
 => => exporting layers                                                                                                          0.1s
 => => writing image sha256:7d681a377f627c30765b92088008d4ac265f182be9ee93efa118400e5667482c                                     0.0s
 => => naming to docker.io/library/websocket-server:1.0                                                                          0.0s
[root@martin-host web]# 
[root@martin-host web]# docker run -tid --name=websocket-server --hostname=localhost --net=host --restart=always websocket-server:1.0  
9fb88729fe38c44841a2691562deb47b428013150fcdc5974d8c06f43630e679

2024-07-19 03:39:14.976  INFO 1 --- [           main] o.s.b.w.embedded.tomcat.TomcatWebServer  : Tomcat started on port(s): 8088 (http) with context path ''