Docker镜像创建

李小白是一只喵

发布于 2020-04-23 15:17:54

1.1K0

发布于 2020-04-23 15:17:54

文章被收录于专栏：算法微时光算法微时光

创建镜像

创建镜像有两种方式： 1、从已经创建的容器中更新镜像，并且提交这个镜像 2、使用 Dockerfile 指令来创建一个新的镜像

从原有镜像创建

废话不多，下面开始操作：

使用vi创建一个index.html文件,文件的内容为：

<html>

<head>

<meta charset="UTF-8">

<title>Document</title>

</head>

<body>

Hello World！

</body>

</html>

２．使用cp命令将index.html复制到容器中，cp命令使用说明：

$ sudo docker cp --help

Usage:  docker cp [OPTIONS] CONTAINER:SRC_PATH DEST_PATH|-
    docker cp [OPTIONS] SRC_PATH|- CONTAINER:DEST_PATH

Copy files/folders between a container and the local filesystem

Use '-' as the source to read a tar archive from stdin
and extract it to a directory destination in a container.
Use '-' as the destination to stream a tar archive of a
container source to stdout.

Options:
  -a, --archive       Archive mode (copy all uid/gid information)
  -L, --follow-link   Always follow symbol link in SRC_PATH

注意提前要启动容器：

$ sudo docker ps -a
$ sudo docker start 9fe0e4b5b4a3

执行效果：

然后在执行cp命令：

$ docker cp index.html 9fe0e4b5b4a3:/usr/share/nginx/html/

/usr/share/nginx/html/是web服务的文件目录。然后执行commit命令，命令说明：

$  docker commit --help

Usage:  docker commit [OPTIONS] CONTAINER [REPOSITORY[:TAG]]

Create a new image from a container's changes

Options:
  -a, --author string    Author (e.g., "John Hannibal Smith <hannibal@a-team.com>")
  -c, --change list      Apply Dockerfile instruction to the created image
  -m, --message string   Commit message
  -p, --pause            Pause container during commit (default true)

执行命令：

$ docker commit -a "Li XiaoBai" -m "Modify index.html" 9fe0e4b5b4a3 nginx/hello:hello

使用docker images就可以看到新添加的镜像了。执行效果：

使用run命令运行新添加的镜像：

sudo docker run --name nginx-hello1 -p 8080:80 -d d5002b6f7260

然后打开浏览器，输入127.0.0.1:8080就可以看到我们添加的网页了：

第一步制作镜像成功。＾＿＾

使用 Dockerfile制作镜像

先来看一下build命令的使用说明：

$ sudo docker build --help

Usage:  docker build [OPTIONS] PATH | URL | -

Build an image from a Dockerfile

Options:
      --add-host list           Add a custom host-to-IP mapping (host:ip)
      --build-arg list          Set build-time variables
      --cache-from strings      Images to consider as cache sources
      --cgroup-parent string    Optional parent cgroup for the container
      --compress                Compress the build context using gzip
      --cpu-period int          Limit the CPU CFS (Completely Fair Scheduler) period
      --cpu-quota int           Limit the CPU CFS (Completely Fair Scheduler) quota
  -c, --cpu-shares int          CPU shares (relative weight)
      --cpuset-cpus string      CPUs in which to allow execution (0-3, 0,1)
      --cpuset-mems string      MEMs in which to allow execution (0-3, 0,1)
      --disable-content-trust   Skip image verification (default true)
  -f, --file string             Name of the Dockerfile (Default is 'PATH/Dockerfile')
      --force-rm                Always remove intermediate containers
      --iidfile string          Write the image ID to the file
      --isolation string        Container isolation technology
      --label list              Set metadata for an image
  -m, --memory bytes            Memory limit
      --memory-swap bytes       Swap limit equal to memory plus swap: '-1' to enable unlimited swap
      --network string          Set the networking mode for the RUN instructions during build (default "default")
      --no-cache                Do not use cache when building the image
      --pull                    Always attempt to pull a newer version of the image
  -q, --quiet                   Suppress the build output and print image ID on success
      --rm                      Remove intermediate containers after a successful build (default true)
      --security-opt strings    Security options
      --shm-size bytes          Size of /dev/shm
  -t, --tag list                Name and optionally a tag in the 'name:tag' format
      --target string           Set the target build stage to build.
      --ulimit ulimit           Ulimit options (default [])

首先再本地创建一个Dockerfile文件，文件内容如下：

FROM    ubuntu 
MAINTAINER      Fisher "Li XiaoBai"

RUN     /bin/echo 'root:123456' |chpasswd
RUN     useradd xiaobai 
RUN     /bin/echo 'xiaobai:123456' |chpasswd
RUN     /bin/echo -e "LANG=\"en_US.UTF-8\"" >/etc/default/local
EXPOSE  22
EXPOSE  80
CMD     /usr/sbin/sshd -D

FROM，指定使用哪个镜像源 RUN 指令告诉docker 在镜像内执行命令，安装了什么

执行创建命令：