2019独角兽企业重金招聘Python工程师标准>>> 
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 [email protected]
# 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 [email protected] #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
Welcome to nginx!