文章目录
Docker 快速入门
Ubuntu 镜像操作
拉取最新的Ubuntn官方镜像
[root@host xwk]# docker pull ubuntu:latest
latest: Pulling from library/ubuntu
7b1a6ab2e44d: Pull complete
Digest: sha256:626ffe58f6e7566e00254b638eb7e0f3b11d4da9675088f4781a50ae288f3322
Status: Downloaded newer image for ubuntu:latest
docker.io/library/ubuntu:latest
查看该镜像的详细信息
docker inspect ubuntu
查看该镜像的构建历史
[root@host xwk]# docker history ubuntu
IMAGE CREATED CREATED BY SIZE COMMENT
ba6acccedd29 3 weeks ago /bin/sh -c #(nop) CMD ["bash"] 0B
<missing> 3 weeks ago /bin/sh -c #(nop) ADD file:5d68d27cc15a80653… 72.8MB
[root@host xwk]#
删除该镜像
[root@host xwk]# docker rmi ubuntu
Untagged: ubuntu:latest
Untagged: ubuntu@sha256:626ffe58f6e7566e00254b638eb7e0f3b11d4da9675088f4781a50ae288f3322
Deleted: sha256:ba6acccedd2923aee4c2acc6a23780b14ed4b8a5fa4e14e252a23b846df9b6c1
Deleted: sha256:9f54eef412758095c8079ac465d494a2872e02e90bf1fb5f12a1641c0d1bb78b
[root@host xwk]#
构建在 Ubuntu 系统上运行 Nginx 的镜像
使用 docker commit 命令基于容器构建镜像
以交互方式启动 ubuntu 容器
[root@host xwk]# docker history centos
Error response from daemon: No such image: centos:latest
[root@host xwk]# docker run -it ubuntu /bin/bash
Unable to find image 'ubuntu:latest' locally
latest: Pulling from library/ubuntu
7b1a6ab2e44d: Pull complete
Digest: sha256:626ffe58f6e7566e00254b638eb7e0f3b11d4da9675088f4781a50ae288f3322
Status: Downloaded newer image for ubuntu:latest
在该容器中执行以下命令安装 nginx
更新软件包
apt update
安装 Nginx
apt install -y nginx
过程中需要选择亚洲和上海
检查nginx服务版本
nginx -v
nginx version: nginx/1.18.0 (Ubuntu)
基于该容器生成新的镜像。
先退出容器，再执行 docker commit 命令将该容器提交并在本地生成新的镜像。
exit
[root@host xwk]# docker commit d7aaabf0105b ubuntu-with-nginx
sha256:a4d027ba7f66f4c93cfa8a9aa4f4bbfe8391a1e9be6be218cbd253ee6d358d58
[root@host xwk]#
d7aaabf0105b可以在命令行root@d7aaabf0105b看到，每个人应该都不一样
基于新的镜像启动新容器
以交互方式启动容器之后，在容器中执行 nginx 命令启动 Nginx 服务，然后使用 ps –aux
查看相关的进程，结果表明已成功运行 Nginx 服务
[root@host xwk]# docker run -it ubuntu-with-nginx /bin/bash
root@e839944e18c1:/#
root@e839944e18c1:/# nginx
root@e839944e18c1:/# ps -aux
USER PID %CPU %MEM VSZ RSS TTY STAT START TIME COMMAND
root 1 0.0 0.2 4104 2168 pts/0 Ss 19:56 0:00 /bin/bash
root 9 0.0 0.1 55276 1444 ? Ss 19:57 0:00 nginx: master process nginx
www-data 10 0.0 0.2 55600 2100 ? S 19:57 0:00 nginx: worker process
root 11 0.0 0.1 5892 1412 pts/0 R+ 19:57 0:00 ps -aux
root@e839944e18c1:/#
[root@host bin]# docker run --rm -it -p 8000:80 ubuntu-with-nginx /bin/bash
root@afaa559381c6:/# nginx
exit
[root@host bin]# docker stop ubuntu-with-nginx
ubuntu-with-nginx
[root@host bin]#
使用 docker build 命令基于 Dockerfile 构建镜像
准备构建 Dockerfile 构建上下文。
建立一个目录用作 Dockerfile 的构建上下文并准备所需的文件
[root@host bin]# mkdir ubuntu-nginx && cd ubuntu-nginx
[root@host ubuntu-nginx]#
编写 Dockerfile 文件。
可以使用 nano 进行编辑
nano Dockerfile
# 从基础镜像 ubuntu 开始构建
FROM ubuntu:latest
# 安装 nginx
RUN apt update && apt install -y nginx
# 修改 nginx 首页信息
RUN echo "Hello! This is nginx server " > /usr/share/nginx/html/index.html
# 对外暴露 80 端口
EXPOSE 80
# 启动 nginx
CMD ["nginx", "-g", "daemon off;"]
不要忘了后面的点号，代表当前路径
docker build -t ubuntu-with-nginx:1.0 .
等待运行完毕，出现下面语句代表安装成功
Successfully built 7175ab8a67d3
Successfully tagged ubuntu-with-nginx:1.0
基于该镜像启动容器进行测试
[root@host ubuntu-nginx]# docker run --rm -d -p 8000:80 --name test-nginx ubuntu-with-nginx:1.0
03a07c0ffa98e8ee63abf0a5aafd6d6ae3a57b30829a0ca2df5082568b336ca4
[root@host ubuntu-nginx]# curl 127.0.0.1:8000
<!DOCTYPE html>
<html>
<head>
<title>Welcome to nginx!</title>
<style>
body {
width: 35em;
margin: 0 auto;
font-family: Tahoma, Verdana, Arial, sans-serif;
}
</style>
</head>
<body>
<h1>Welcome to nginx!</h1>
<p>If you see this page, the nginx web server is successfully installed and
working. Further configuration is required.</p>
<p>For online documentation and support please refer to
<a href="http://nginx.org/">nginx.org</a>.<br/>
Commercial support is available at
<a href="http://nginx.com/">nginx.com</a>.</p>
<p><em>Thank you for using nginx.</em></p>
</body>
</html>
[root@host ubuntu-nginx]#
不过这里发现首页修改并未成功。这在下面来解决。
实验完毕，停止该容器，该容器会被自动删除。
[root@host ubuntu-nginx]# docker stop test-nginx
test-nginx
[root@host ubuntu-nginx]#
测试镜像构建的缓存
Ubuntu 操作系统中使用 apt 安装 Nigix 服务器，默认的首页位于/var/www/html 目录中。继
续修改 Dockerfile，将首页修改语句改为：
vim Dockerfile
RUN echo "Hello! This is nginx server " > /usr/share/nginx/html/index.html && cp /usr/share/nginx/html/index.html /var/www/html
[root@host ubuntu-nginx]# docker build -t ubuntu-with-nginx:2.0 .
Sending build context to Docker daemon 2.048kB
Step 1/5 : FROM ubuntu:latest
---> ba6acccedd29
Step 2/5 : RUN apt update && apt install -y nginx
---> Using cache
---> 1387c9ed6b73
Step 3/5 : RUN echo "Hello! This is nginx server " > /usr/share/nginx/html/index.html && cp /usr/share/nginx/html/index.html /var/www/html
---> Running in e123fd673fd7
Removing intermediate container e123fd673fd7
---> badf623cb613
Step 4/5 : EXPOSE 80
---> Running in 0b7c77fdf090
Removing intermediate container 0b7c77fdf090
---> 05f6b9452b59
Step 5/5 : CMD ["nginx", "-g", "daemon off;"]
---> Running in eee74e4f7018
Removing intermediate container eee74e4f7018
---> 5b554fcd0896
Successfully built 5b554fcd0896
Successfully tagged ubuntu-with-nginx:2.0
[root@host ubuntu-nginx]#
[root@host ubuntu-nginx]# docker run --rm -d -p 8000:80 --name test-nginx ubuntu-with-nginx:2.0
03c213dc4abee9a8404c8ad4147f1d90ff44cabcae56fd6db95deea7f23ce5f4
[root@host ubuntu-nginx]#
[root@host ubuntu-nginx]# curl 127.0.0.1:8000
Hello! This is nginx server
[root@host ubuntu-nginx]#
Nginx 网站首页已经修改成功
实验完毕，停止该容器，该容器会被自动删除。
[root@host ubuntu-nginx]# docker stop test-nginx
test-nginx
[root@host ubuntu-nginx]#