Docker生产实践（六）

镜像构建思路

思路：分层设计

最底层：系统层，构建自己适用的不同操作系统镜像；

中间层：根据运行环境，如php、java、python等，构建业务基础运行环境层镜像；

最上层：根据具体的业务模块，构建应用服务层镜像。

目录构建树结构

案例1：centos 7系统镜像构建

cd  /root
mkdir  -p  /root/docker/system/centos
cd  /root/docker/system/centos
wget -O  /etc/yum .repos.d /epel .repo http: //mirrors .aliyun.com /repo/epel-7 .repo   # 下载阿里RHEL 7 epel源
cp  /etc/yum .repos.d /epel .repo epel.repo

创建镜像文件

vim Dockerfile
# This Dockerfile

# Base image
FROM centos

# Who
MAINTAINER shhnwangjian [email protected]

# EPEL
ADD epel.repo  /etc/yum .repos.d/

# Base pkg
RUN yum  install  -y wget supervisor git tree net-tools  sudo  psmisc mysql-devel && yum clean all

构建镜像

docker build -t shhnwangjian /centos :base .

 

案例2：基于案例1的centos系统镜像，构建python运行环境镜像

mkdir  -p  /root/docker/runtime/python
cd  /root/docker/runtime/python

创建镜像文件

vim Dockerfile
# Base image
FROM shhnwangjian /centos :base

# Who
MAINTAINER shhnwangjian [email protected]

# Python env
RUN yum  install  -y python-devel python-pip supervisor

# Upgrade pip
RUN pip  install  --upgrade pip

构建镜像

docker build -t shhnwangjian /python  .

 

案例3：构建带SSH功能的centos 7系统镜像

mkdir  -p  /root/docker/system/centos-ssh
cd  /root/docker/system/centos-ssh
wget -O  /etc/yum .repos.d /epel .repo http: //mirrors .aliyun.com /repo/epel-7 .repo   # 下载阿里RHEL 7 epel源
cp  /etc/yum .repos.d /epel .repo epel.repo

创建镜像文件

# Docker for CentOS

# Base image
FROM centos

# Who
MAINTAINER shhnwangjian [email protected]

# EPEL
ADD epel.repo  /etc/yum .repos.d/

# Base pkg
RUN yum  install  -y openssh-clients openssl-devel openssh-server wget supervisor git tree net-tools  sudo  psmisc mysql-devel && yum clean all

# For SSHD
RUN  ssh -keygen -t rsa -f  /etc/ssh/ssh_host_rsa_key
RUN  ssh -keygen -t ecdsa -f  /etc/ssh/ssh_host_ecdsa_key
RUN  echo  "root:123456"  | chpasswd

构建镜像

docker build -t shhnwangjian /centos-ssh  .

 

案例4：基于案例3的centos-ssh系统镜像，构建python-ssh运行环境镜像

mkdir  -p  /root/docker/runtime/python-ssh
cd  /root/docker/runtime/python-ssh

创建镜像文件

# Base image
FROM shhnwangjian /centos-ssh

# Who
MAINTAINER shhnwangjian [email protected]

# Python env
RUN yum  install  -y python-devel python-pip supervisor

# Upgrade pip
RUN pip  install  --upgrade pip

构建镜像

docker build -t shhnwangjian /python-ssh  .

 

案例5：基于案例4的python-ssh镜像，构建app应用服务镜像

mkdir  -p  /root/docker/app/web-app
cd  /root/docker/app/web-app

应用程序文件app.py

from flask  import  Flask

app = Flask(__name__)

@app.route( '/' )
def hello():
        return  "Hello World!"

if  __name__ ==  "__main__" :
        app.run(host= "0.0.0.0" , debug=True)

python依赖包文件requirements.txt

Flask

supervisor配置文件app-supervisor.ini

[program:web-api]
command = /usr/bin/python2 .7  /opt/app .py
process_name=%(program_name)s
autostart= true
user=www
stdout_logfile= /tmp/app .log
stderr_logfile= /tmp/app .error

[program:sshd]
command = /usr/sbin/sshd  -D
process_name=%(program_name)s
autostart= true

在宿主机上安装supervisor，将默认生成的supervisord.conf放入docker构建环境目录下

  conf

备注：nodaemon=true ，前台启动

创建镜像文件

# Base image
FROM shhnwangjian /python-ssh

# Who
MAINTAINER shhnwangjian [email protected]

# ADD user www
RUN  useradd  -s  /sbin/nologin  -M www

# ADD file
ADD app.py  /opt/app .py
ADD requirements.txt  /opt/
ADD supervisord.conf  /etc/supervisord .conf
ADD app-supervisor.ini  /etc/supervisord .d/

# Pip install
RUN  /usr/bin/pip2 .7  install  -r  /opt/requirements .txt

# Port
EXPOSE 22 5000

# CMD
CMD [ "/usr/bin/supervisord" ,  "-c" ,  "/etc/supervisord.conf" ]

构建镜像

docker build -t shhnwangjian /web-api  .

启动容器

docker run --name web-api -d -p 88:5000 -p 8022:22 shhnwangjian /web-api