使用 Dockerfile 制作镜像

使用 Dockerfile 制作镜像

2.10.1. 基于 Dockerfile 创建镜像

为什么要自己创建镜像呢？ 因为官方提供的镜像无法满足我们的需求，例如 nginx 镜像你会发现 ps, top 等等很多命令缺失。

2.10.1.1. 创建 Dockerfile 文件

需求基于centos7镜像创建nginx stable最新版本镜像

		
############################################################
# Dockerfile to build Nginx container
# Based on centos7
############################################################

FROM centos:latest

MAINTAINER Netkiller <[email protected]>

# Install EPEL
RUN yum install -y epel-release && yum clean all

# Update RPM Packages
RUN yum -y update

# Install Nginx
RUN rpm -ivh http://nginx.org/packages/centos/7/noarch/RPMS/nginx-release-centos-7-0.el7.ngx.noarch.rpm
RUN yum install -y nginx
RUN yum clean all

# forward request and error logs to docker log collector
RUN ln -sf /dev/stdout /var/log/nginx/access.log
RUN ln -sf /dev/stderr /var/log/nginx/error.log

# be backwards compatible with pre-official images
#RUN ln -sf ../share/nginx /usr/local/nginx

# prepare container

# add startup script
#ADD startup.sh /startup.sh
#RUN chmod 755 /startup.sh

VOLUME ["/etc/nginx"]
VOLUME ["/usr/share/nginx/html"]
VOLUME ["/var/www"]

EXPOSE 80 443

CMD ["nginx", "-g", "daemon off;"]
		
			

2.10.1.2. 创建镜像

		
# docker build -t "centos:nginx" .
Sending build context to Docker daemon 3.072 kB
Step 1/14 : FROM centos:latest
 ---> 3bee3060bfc8
Step 2/14 : MAINTAINER Netkiller <[email protected]>
 ---> Using cache
 ---> 8f351964d568
Step 3/14 : RUN yum install -y epel-release && yum clean all
 ---> Using cache
 ---> bf86eff77ff3
Step 4/14 : RUN yum -y update
 ---> Using cache
 ---> 4915172ac4f3
Step 5/14 : RUN rpm -ivh http://nginx.org/packages/centos/7/noarch/RPMS/nginx-release-centos-7-0.el7.ngx.noarch.rpm
 ---> Using cache
 ---> 4a919bd141c9
Step 6/14 : RUN yum install -y nginx
 ---> Using cache
 ---> 2718221eab8c
Step 7/14 : RUN yum clean all
 ---> Using cache
 ---> 62231a5f1d76
Step 8/14 : RUN ln -sf /dev/stdout /var/log/nginx/access.log
 ---> Using cache
 ---> 38be8f0cc782
Step 9/14 : RUN ln -sf /dev/stderr /var/log/nginx/error.log