1.通过编写Dockerfile自己创建镜像

vagrant@ubuntu-xenial:/data/www$ sudo mkdir d1 && cd d1
vagrant@ubuntu-xenial:/data/www/d1$ sudo vi Dockerfile

写入

FROM alpine:latest        #使用一个基础镜像Alipine
MAINTAINER youer          #作者
CMD echo "hello docker"   #运行一个命令

2. 使用docker build 构建一个镜像,其中 -t （镜像的名字及标签，通常 name:tag 或者 name 格式）, . 表示当前目录下的内容都送给docker daemon 产生一个镜像(image)

   vagrant@ubuntu-xenial:/data/www/d1$ docker build -t hello_docker .     #构建一个镜像(image)
   Sending build context to Docker daemon  2.048kB
   Step 1/3 : FROM alpine:latest
   latest: Pulling from library/alpine
   df20fa9351a1: Pull complete
   Digest: sha256:185518070891758909c9f839cf4ca393ee977ac378609f700f60a771a2dfe321
   Status: Downloaded newer image for alpine:latest
    ---> a24bb4013296
   Step 2/3 : MAINTAINER youer
    ---> Running in a3e2bba91734
   Removing intermediate container a3e2bba91734
    ---> 6e866d4ff44b
   Step 3/3 : CMD echo "hello docker"
    ---> Running in 57300c2509cd
   Removing intermediate container 57300c2509cd
    ---> e8798fbd35bc
   Successfully built e8798fbd35bc
   Successfully tagged hello_docker:latest
   
   vagrant@ubuntu-xenial:/data/www/d1$ docker images    #查看创建的镜像(images)
   REPOSITORY          TAG                 IMAGE ID            CREATED              SIZE
   hello_docker        latest              e8798fbd35bc        About a minute ago   5.57MB      #即为我们刚刚创建的hello_docker的镜像
   intelligent_knuth   latest              f6bea6b5d8c6        About an hour ago    133MB
   ubuntu              latest              4e2eef94cd6b        2 weeks ago          73.9MB
   nginx               latest              4bb46517cac3        3 weeks ago          133MB
   alpine              latest              a24bb4013296        3 months ago         5.57MB
   
   vagrant@ubuntu-xenial:/data/www/d1$ docker run hello_docker    # 运行这个镜像输出hello docker
   hello docker
   vagrant@ubuntu-xenial:/data/www/d1$

3. 下面我们创建一个较复杂的镜像作为演示

   vagrant@ubuntu-xenial:/data/www$ sudo mkdir d2 &&  cd d2
   vagrant@ubuntu-xenial:/data/www/d2$ sudo vi Dockerfile

   写入

   FROM ubuntu                                                                       #使用一个基础镜像ubuntu
   MAINTAINER nz                                                                     #作者名称
   RUN sed -i 's/archive.ubuntu.com/mirrors.ustc.edu.cn/g'  /etc/apt/sources.list    #加速使用国内镜像
   RUN apt-get update                                                                #更新一下ubuntu程序库
   RUN apt-get install -y nginx                                                      #安装一个nginx
   COPY index.html /var/www/html                                                     #修改nginx默认显示
   ENTRYPOINT ["/usr/sbin/nginx","-g","daemon off;"]                                 #运行nginx不以守护进程的方式启动
   EXPOSE 80                                                                         #暴漏一个端口

   注意： nginx默认是以后台模式启动的，Docker未执行自定义的CMD之前，nginx的pid是1，执行到CMD之后，nginx就在后台运行，bash或sh脚本的pid变成了1。
   所以一旦执行完自定义CMD，nginx容器也就退出了。为了保持nginx的容器不退出，应该关闭nginx后台运行

   vagrant@ubuntu-xenial:/data/www/d2$ sudo vi index.html

   写入

    dockerfile-nginx  

   执行构建镜像命令

   vagrant@ubuntu-xenial:/data/www/d2$ docker build -t dockerfiel/nginx .   #构建一个镜像(image)
   Sending build context to Docker daemon  3.072kB
   Step 1/8 : FROM ubuntu
    ---> 4e2eef94cd6b
   Step 2/8 : MAINTAINER youer
    ---> Running in 2d3d3aa2856a
   Removing intermediate container 2d3d3aa2856a
    ---> cdbb8ec79689
   Step 3/8 : RUN sed -i 's/archive.ubuntu.com/mirrors.ustc.edu.cn/g'  /etc/apt/sources.list
    ---> Running in 82c99efdfd80
   Removing intermediate container 82c99efdfd80
    ---> 6fc9b3f9f95e
   Step 4/8 : RUN apt-get update
    ---> Running in e2ca44c3e909
    Setting up nginx (1.18.0-0ubuntu1) ...
    Processing triggers for libc-bin (2.31-0ubuntu9) ...
    Removing intermediate container 97070963bb2c
     ---> d7bd2e56614c
    Step 6/8 : COPY index.html /var/www/html
     ---> bd5d2ca18a19
    Step 7/8 : ENTRYPOINT ["/usr/sbin/nginx","-g","daemon off;"]
     ---> Running in 7de655d9034d
    Removing intermediate container 7de655d9034d
     ---> 83a294795bc7
    Step 8/8 : EXPOSE 80
     ---> Running in 5b4549e15f9b
    Removing intermediate container 5b4549e15f9b
     ---> ccc10b2d21b6
    Successfully built ccc10b2d21b6
    Successfully tagged dockerfiel/nginx:latest
    
    vagrant@ubuntu-xenial:/data/www/d2$ docker images     #可以看到我们刚创建的dockerfiel/nginx镜像
    REPOSITORY          TAG                 IMAGE ID            CREATED              SIZE
    dockerfiel/nginx    latest              ccc10b2d21b6        About a minute ago   156MB
    hello_docker        latest              e8798fbd35bc        48 minutes ago       5.57MB
    intelligent_knuth   latest              f6bea6b5d8c6        2 hours ago          133MB
    ubuntu              latest              4e2eef94cd6b        2 weeks ago          73.9MB
    nginx               latest              4bb46517cac3        3 weeks ago          133MB
    alpine              latest              a24bb4013296        3 months ago         5.57MB

   运行这个镜像

   vagrant@ubuntu-xenial:/data/www/d2$ docker run -p 80:80 -d dockerfiel/nginx     #运行这个镜像
   44eac38c0fe284c519d64711c2d152391ac8849e67b832fda330c9c7ee1b90c2
   
   vagrant@ubuntu-xenial:/data/www/d2$ docker ps                                   #创建了一个容器
   CONTAINER ID        IMAGE               COMMAND                  CREATED             STATUS              PORTS                NAMES
   44eac38c0fe2        dockerfiel/nginx    "/usr/sbin/nginx -g …"   8 seconds ago       Up 7 seconds        0.0.0.0:80->80/tcp   romantic_ishizaka
   vagrant@ubuntu-xenial:/data/www/d2$

   我们在本机访问一下： http://192.168.33.12/