Docker学习之4——构建NGINX镜像

Nginx是一个高性能的Web和反向代理服务器，它具有很多非常优越的特性：
1、作为Web服务器。
2、作为负载均衡服务器。
3、作为邮件代理服务器。
4、安装及配置简单。
接下来我们介绍在docker构建nginx镜像：
Docker镜像构建分为两种方式：

1. 手动构建
2. Dockerfile（自动构建）

一、Docker镜像手动构建实例

基于centos镜像进行构建nginx镜像
#下载镜像
[root@compute ~]# docker pull centos
[root@compute ~]# docker pull nginx
[root@compute ~]# docker images
REPOSITORY          TAG                 IMAGE ID            CREATED             SIZE
docker.io/centos    latest              ff426288ea90        13 days ago         207.2 MB
docker.io/nginx     latest              3f8a4339aadd        3 weeks ago         108.5 MB
#先创建centos镜像
[root@compute ~]# docker run --name nginxdocker -ti centos
[root@10859f0ffd78 /]# yum install -y wget
[root@10859f0ffd78 /]# wget -O /etc/yum.repos.d/epel.repo http://mirrors.aliyun.com/repo/epel-7.repo
#安装nginx
[root@10859f0ffd78 /]# yum install -y nginx
[root@10859f0ffd78 /]# sed -i '3a daemon off;' /etc/nginx/nginx.conf
[root@10859f0ffd78 /]# exit
[root@compute ~]# docker ps -a
CONTAINER ID        IMAGE                COMMAND                  CREATED             STATUS                      PORTS                NAMES
10859f0ffd78        centos               "/bin/bash"              7 minutes ago       Exited (0) 19 seconds ago                        nginxdocker
#构建镜像
[root@compute ~]# docker commit -m "test Nginx" 10859f0ffd78 nginxdocker/nginxdocker:v1
sha256:616e9d624b9a1db8e23491db331228ca56dd60c04356da14ab6d7e4cf821d415
You have new mail in /var/spool/mail/root
[root@compute ~]# docker images
REPOSITORY                TAG                 IMAGE ID            CREATED             SIZE
nginxdocker/nginxdocker   v1                  616e9d624b9a        10 seconds ago      383.9 MB
#启动容器
[root@compute ~]# docker run --name nginxserver -d -p 82:80 nginxdocker/nginxdocker:v1 nginx
c2ded9ce8af76c3b4862ca54478d39429879c856a2751957c9287df077dfcf17
[root@compute ~]# docker ps
CONTAINER ID        IMAGE                        COMMAND             CREATED             STATUS              PORTS                NAMES
c2ded9ce8af7        nginxdocker/nginxdocker:v1   "nginx"             21 seconds ago      Up 19 seconds       0.0.0.0:82->80/tcp   nginxserver
#测试
[root@compute ~]# curl  -I 192.168.128.165:82
HTTP/1.1 200 OK
Server: nginx/1.12.2
Date: Mon, 22 Jan 2018 08:15:39 GMT
Content-Type: text/html
Content-Length: 3700
Last-Modified: Wed, 18 Oct 2017 08:08:18 GMT
Connection: keep-alive
ETag: "59e70bf2-e74"
Accept-Ranges: bytes

二、Docker镜像自动构建实例

Dockerfile是一个文本格式的配置文件，用户可以使用Dockerfile快速创建自定义的镜像。
Dockerfile由一行行命令语句组成，#号注释。分为：基础镜像信息、维护者信息、镜像操作指令和容器启动时执行指令。

#创建目录
[root@compute ~]# mkdir /dokerfile
[root@compute ~]# cd /dokerfile/
[root@compute dokerfile]# mkdir nginx
[root@compute dokerfile]# cd nginx/
#添加Dockerfile文件注意D大写
[root@compute nginx]# vim Dockerfile
#This dockerfile uses the centos image
#VERSION 2 - EDITION 1
#Author:jianlaihe
#Command format:
# 指定基于的基础镜像
FROM centos
 
#维护者信息
MAINTAINER jianlaihe hejianlai@dnion.com
 
#镜像的操作指令
RUN yum install -y wget
RUN wget -O /etc/yum.repos.d/epel.repo http://mirrors.aliyun.com/re
po/epel-7.repo
RUN yum install -y nginx
RUN echo "daemon off;" >>/etc/nginx/nginx.conf
#添加文件需存在当前目录下
ADD index.html /usr/share/nginx/html/index.html
EXPOSE 80
#容器启动时执行命令
CMD /usr/sbin/nginx
 
[root@compute nginx]# echo "hello docker" >index.html
#docker build命令构建镜像名为nginx版本v2
[root@compute nginx]# docker build -t nginx:v2 .
Complete!
 ---> 5e37422db8b2
Removing intermediate container 87fa82c1173a
Step 6 : RUN echo "daemon off;" >>/etc/nginx/nginx.conf
 ---> Running in a03da9a96436
 ---> 236590c11b39
Removing intermediate container a03da9a96436
Step 7 : ADD index.html /usr/share/nginx/html/index.html
 ---> ac28fc354cad
Removing intermediate container 5c2d9944e6f3
Step 8 : EXPOSE 80
 ---> Running in 0b598a0680b8
 ---> d4addb2c20ba
Removing intermediate container 0b598a0680b8
Step 9 : CMD /usr/sbin/nginx
 ---> Running in d1feaede849f
 ---> 4905d9869aa7
Removing intermediate container d1feaede849f
Successfully built 4905d9869aa7
[root@compute nginx]# docker images
REPOSITORY                TAG                 IMAGE ID            CREATED             SIZE
nginx                     v2                  4905d9869aa7        53 seconds ago      404.1 MB
#启动容器
[root@compute nginx]# docker run --name testnginx -d -p 83:80 nginx:v2
b2cd72936465464bb8a88e9b3c5df0015241c7d17cb74062433ef79582c58908
#测试
[root@compute nginx]# curl  192.168.128.165:83
hello docker