docker学习笔记(五)：docker镜像格式_dockerfile格式

墨蓝 2022-10-02 03:53 371阅读 0赞

[2019独角兽企业重金招聘Python工程师标准>>> ][2019_Python_] ![hot3.png][]

**1**、docker 镜像格式：

**创建镜像的方法**：

1)、可以通过现有的镜像做成容器， 然后在容器里做一些操作后,然后在导出成镜像；

2)、去openvz的官网去下载一个模板；

3)、通过dockerfile 来创建镜像；

**dockerfile使用**；nginx的镜像；

在当前目录新建 Dockerfile文件,文件内容如下，随后执行；

[root@localhost_001 ~]# cat Dockerfile 
    ## Set the base image to CentOS
    FROM centos
    # File Author / Maintainer
    MAINTAINER yuanhh yuanhh@linux.com
    # Install necessary tools
    RUN yum install -y pcre-devel wget net-tools gcc zlib zlib-devel make openssl-devel
    # Install Nginx
    ADD http://nginx.org/download/nginx-1.8.0.tar.gz .
    RUN tar zxvf nginx-1.8.0.tar.gz
    RUN mkdir -p /usr/local/nginx
    RUN cd nginx-1.8.0 && ./configure --prefix=/usr/local/nginx && make && make install
    RUN rm -fv /usr/local/nginx/conf/nginx.conf
    ADD http://www.apelearn.com/study_v2/.nginx_conf  /usr/local/nginx/conf/nginx.conf
    # Expose ports
    EXPOSE 80
    # Set the default command to execute when creating a new container
    ENTRYPOINT /usr/local/nginx/sbin/nginx && tail -f /etc/passwd
    #tail  -f  表示参数表示这个容器一直执行,一直不退出;

**执行**：  docker   build  -t  centos\_nginx  .

先执行下容器是否可以上网,因为需要包需要联网;
    [root@localhost_001 ~]# docker run -itd centos     
    4a1bc3528bd3d780b2d0595f0c51ebcde805c5534e3c8121dd0174885e9e8cbd
    [root@localhost_001 ~]# docker exec -it 4a1bc3 bash
    [root@4a1bc3528bd3 /]# ping www.baidu.com
    PING www.a.shifen.com (61.135.169.121) 56(84) bytes of data.
    64 bytes from 61.135.169.121 (61.135.169.121): icmp_seq=1 ttl=127 time=7.77 ms
    1 packets transmitted, 1 received, 0% packet loss, time 0ms
    rtt min/avg/max/mdev = 7.777/7.777/7.777/0.000 ms
    [root@4a1bc3528bd3 /]# exit
    exit
    开始执行;
    [root@localhost_001 ~]# docker build -t centos6_nginx .
    Sending build context to Docker daemon  571.8MB
    Step 1/11 : FROM centos                  #第一步
     ---> afa1f6db949f
    Step 2/11 : MAINTAINER yuanhh yuanhh@linux.com       #第二步
     ---> Using cache
     ---> aa3feac756d0
    Step 3/11 : RUN yum install -y pcre-devel wget net-tools gcc zlib zlib-devel make openssl-devel
     ---> Running in 723f96cbe94b
    Loaded plugins: fastestmirror
    Setting up Install Process
    Resolving Dependencies
    --> Running transaction check
    Step 8/11 : RUN rm -fv /usr/local/nginx/conf/nginx.conf           #删除这个文件
     ---> Running in a479c3faf99c
    removed '/usr/local/nginx/conf/nginx.conf'
    Removing intermediate container a479c3faf99c
     ---> 5fe53914a0fe
    Step 9/11 : ADD http://www.apelearn.com/study_v2/.nginx_conf  /usr/local/nginx/conf/nginx.conf
    Downloading [==================================================>]  1.678kB/1.678kB
     ---> 59650a3fb20e 
    Step 10/11 : EXPOSE 80                   #映射端口
     ---> Running in cc9812e02957
    Removing intermediate container cc9812e02957
     ---> 6cae38f00587
    Step 11/11 : ENTRYPOINT /usr/local/nginx/sbin/nginx && tail -f /etc/passwd    #执行
     ---> Running in 7f9b5b7f76bb
    Removing intermediate container 7f9b5b7f76bb
     ---> 2253fb95f446
    Successfully built 2253fb95f446
    Successfully tagged centos6_nginx:latest

注释：如上，centos新建的包含nginx的镜像生成；            docker  images

[root@localhost_001 ~]# docker images
    REPOSITORY                     TAG                 IMAGE ID            CREATED             SIZE
    centos6_nginx                  latest              2253fb95f446        2 minutes ago       379MB

**启动这个镜像**；     docker  run    -itd  -p   81:80   centos6\_nginx   bash

[root@localhost_001 ~]# docker run -itd -p 81:80 centos6_nginx bash
    f3f493c910942b2fcac68ab347596d6f08eb9b6ab8104b7b722a1a9829e32b9e
    
    [root@localhost_001 ~]# docker exec -it f3f493 bash
    [root@f3f493c91094 /]# ps aux |grep nginx
    root          1  0.8  0.1  11680  1356 pts/0    Ss+  02:47   0:00 /bin/sh -c /usr/local/nginx/sbin/nginx && tail -f /etc/passwd bash
    root          7  0.0  0.0  24880   792 ?        Ss   02:47   0:00 nginx: master process /usr/local/nginx/sbin/nginx
    nobody        8  0.0  0.3  27324  3364 ?        S    02:47   0:00 nginx: worker process
    nobody        9  0.0  0.3  27324  3364 ?        S    02:47   0:00 nginx: worker process
    root         25  0.0  0.0   9088   672 pts/1    S+   02:48   0:00 grep --color=auto nginx
    [root@f3f493c91094 /]# netstat -lnp
    Active Internet connections (only servers)
    Proto Recv-Q Send-Q Local Address           Foreign Address         State       PID/Program name    
    tcp        0      0 0.0.0.0:80              0.0.0.0:*               LISTEN      7/nginx: master pro 
    Active UNIX domain sockets (only servers)
    Proto RefCnt Flags       Type       State         I-Node   PID/Program name     Path

注释：发现容器已经启动了nginx服务,镜像到本机的81端口;

在宿主机访问81端口；   curl  localhost:81

[root@localhost_001 ~]# netstat -lnp
    Active Internet connections (only servers)
    Proto Recv-Q Send-Q Local Address           Foreign Address         State       PID/Program name    
    tcp        0      0 0.0.0.0:22              0.0.0.0:*               LISTEN      829/sshd            
    tcp        0      0 0.0.0.0:56888           0.0.0.0:*               LISTEN      829/sshd            
    tcp        0      0 127.0.0.1:25            0.0.0.0:*               LISTEN      1062/master         
    tcp6       0      0 :::81                   :::*                    LISTEN      5959/docker-proxy  
    [root@f3f493c91094 /]# curl localhost 81
    <!DOCTYPE html>
    <html>
    <head>
    <title>Welcome to nginx!</title>
    <style>
        body {
            width: 35em;
            margin: 0 auto;
            font-family: Tahoma, Verdana, Arial, sans-serif;

**2**、用docker  compose   部署服务           用来批量管理容器， 可以同时启动多个容器操作；

docker  compose 可以方便我们快捷高效的管理容器的启动、停止、重启等操作,它类似于linux下的 shell 文件,基于 yaml 语法,在该文件里可以描述应用架构,比如用什么镜像、数据卷、网络模式、监听端口信息，可以在 compose中定义一个多容器的应用(jumpserver)，然后通过 compose 来启动这个应用；

docker-compose   version          查看compose的版本

**Compose区分Version 1和Version 2（Compose 1.6.0+，Docker Engine 1.10.0+）。Version 2支持更多的指令。Version 1 没有声明版本默认是"version 1"。Version 1将来会被弃用。**

[root@localhost_001 ~]# docker-compose version
    docker-compose version 1.17.0-rc1, build a0f95af
    docker-py version: 2.5.1
    CPython version: 2.7.13
    OpenSSL version: OpenSSL 1.0.1t  3 May 2016

去官网下载一个最新版的 compose；

curl -L https://github.com/docker/compose/releases/download/1.17.0-rc1/docker-compose-\`uname -s\`-\`uname -m\` > /usr/local/bin/docker-compose

**或者：**   wget   https://coding.net/u/aminglinux/p/yuanke\_centos7/git/blob/master/25docker/docker-compose-Linux-x86\_64

**安装代码**：

[root@localhost_001 ~]# curl -L https://github.com/docker/compose/releases/download/1.17.0-rc1/docker-compose-`uname -s`-`uname -m` > /usr/local/bin/docker-compose
      % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
                                     Dload  Upload   Total   Spent    Left  Speed
    100   617    0   617    0     0     83      0 --:--:--  0:00:07 --:--:--   127
    100 8649k  100 8649k    0     0   110k      0  0:01:18  0:01:18 --:--:--  160k
    [root@localhost_001 ~]# ls
    1.txt    53.sh            catalina.out                 Dockerfile  pipework  tes.txt  yuanhh_centos_with
    36.sh    anaconda-ks.cfg  centos-6-x86-minimal.tar.gz  file.tar    test      t.txt
    53.1.sh  authorized_keys  CentOS7-Base-163.repo        link        test.txt  yuanhh
    [root@localhost_001 ~]# ls /usr/local/bin/docker-compose 
    /usr/local/bin/docker-compose
    [root@localhost_001 ~]# chmod 755 !$
    chmod 755 /usr/local/bin/docker-compose

**3、**下面写一个compose；               vim     docker-compose.yml   添加 : [添加代码链接][Link 1]

[root@localhost_001 ~]# vim docker-compose.yml 
    version: "2"
    services:
      app1:
        image: fenye_nginx
        ports:
          - "8080:80"
        networks:
          - "net1"
        volumes:
          - /data/:/data          #本地目录：容器目录的映射
        entrypoint: tail -f /etc/passwd
      app2:
        image: centos_nginx
        networks:
          - "net2"
        volumes:
          - /data/:/data1
        entrypoint: tail -f /etc/passwd
    networks:
      net1:
        driver: bridge
      net2:
        driver: bridge

4、启动镜像：  docker-compose up -d(表示后台)                         ||              docker-compose    stop

[root@localhost_001 ~]# docker-compose up -d 
    Creating root_app2_1 ... 
    Creating root_app1_1 ... 
    Creating root_app2_1
    Creating root_app1_1
    Creating root_app1_1 ... done
    [root@localhost_001 ~]# docker ps
    CONTAINER ID        IMAGE               COMMAND                  CREATED             STATUS              PORTS                NAMES
    01ed9551ffd2        centos6_nginx       "tail -f /etc/passwd"    21 seconds ago      Up 14 seconds       80/tcp               root_app2_1
    f3f493c91094        centos6_nginx       "/bin/sh -c '/usr/lo…"   About an hour ago   Up About an hour    0.0.0.0:81->80/tcp   naughty_banzai
    4a1bc3528bd3        centos              "/bin/bash"              2 hours ago         Up 2 hours                               suspicious_kowalevski

docker-compose   支持哪些指令；   up    down              start      stop

[root@localhost_001 ~]# docker-compose --help
      port               Print the public port for a port binding
      ps                 List containers
      pull               Pull service images
      push               Push service images
      restart            Restart services
      rm                 Remove stopped containers
      run                Run a one-off command
      scale              Set number of containers for a service
      start              Start services
      stop               Stop services
      top                Display the running processes
      unpause            Unpause services
      up                 Create and start containers
      version            Show the Docker-Compose version information
    [root@localhost_001 ~]# docker-compose ps
       Name             Command          State     Ports
    ----------------------------------------------------
    root_app1_1   /bin/bash             Exit 0          
    root_app2_1   tail -f /etc/passwd   Exit 137   
    [root@localhost_001 ~]# docker-compose rm -f              #删除已经停止的镜像;
    Going to remove root_app1_1, root_app2_1
    Removing root_app1_1 ... done
    Removing root_app2_1 ... done
    [root@localhost_001 ~]# docker-compose ps                #删除后这里为空
    Name   Command   State   Ports
    ------------------------------
    [root@localhost_001 ~]# docker-compose up -d                  #再次启动docker-compose
    Creating network "root_net2" with driver "bridge"
    Creating network "root_net1" with driver "bridge"
    Creating root_app2_1 ... 
    Creating root_app1_1 ... 
    Creating root_app2_1
    Creating root_app1_1 ... done
    [root@localhost_001 ~]# docker-compose ps                    #查看启动的两个容器
       Name             Command         State          Ports        
    ----------------------------------------------------------------
    root_app1_1   tail -f /etc/passwd   Up      0.0.0.0:8080->80/tcp
    root_app2_1   tail -f /etc/passwd   Up      80/tcp

**注释**：关于docker-compose语法的参考文档    http://www.web3.xin/index/article/182.html

**批量管理服务器**：配置、重启、关机等命令；

expect     shell脚本     ansible     compose(批量来管理容器)

转载于:https://my.oschina.net/yuanhaohao/blog/3023713

[2019_Python_]: https://my.oschina.net/u/2663968/blog/3061697
[hot3.png]: /images/20220113/194beb6dfd434b938e4dd2fa86099d8e.png
[Link 1]: https://coding.net/u/aminglinux/p/yuanke_centos7/git/blob/master/25docker/docker-compose.yml