使用 Python 优雅地编排 Dockerfile!!!

使用 Python 优雅地编排 Dockerfile

使用 python 替代 docker compose 编排容器

docker compose 是 docker 的容器编排工具，它是基于 YAML 配置，YAML 是一种配置文件格式，支持传递环境变量，但是对于复杂的容器编排显得力不从心。

于是我便开发这个程序，可以像写程序一样编排 docker ，可以充分发挥程序猿的想象力。

pip install netkiller-devops

编排 Dockerfile

from netkiller.docker import *

# 实例化 Dockerfile() 对象
nginx = Dockerfile()

# 基于什么镜像
nginx.image('nginx:latest')

# 配置挂载卷
nginx.volume(['/etc/nginx','/var/log/nginx','/opt'])

# 运行脚本
nginx.run('apt update -y && apt install -y procps')

# 暴漏端口
nginx.expose(['80','443'])

# 设置工作目录
nginx.workdir('/opt')

# 打印 Dockerfile
nginx.show()

FROM nginx:latest
VOLUME ["/etc/nginx","/var/log/nginx","/opt"]
RUN apt update -y && apt install -y procps
EXPOSE 80 443
WORKDIR /opt

另一种写法

from netkiller.docker import *

nginx = Dockerfile() 
nginx.image('nginx:latest').volume(['/etc/nginx','/var/log/nginx']).run('apt update -y && apt install -y procps').expose(['80','443']).workdir('/opt')
nginx.render()
nginx.save('/tmp/Dockerfile')

构建 Docker 镜像

from netkiller.docker import *

# 编排 Docker 镜像
dockerfile = Dockerfile()
dockerfile.image('openjdk:8').volume(['/srv']).run(
    'apt update -y && apt install -y procps net-tools iputils-ping iproute2 telnet'
).expose(['80', '443']).workdir('/srv')

# 通过 Service 设置镜像名称是 netkiller:openjdk8
image = Services('image')
image.build(dockerfile)
image.image('netkiller:openjdk8')

# 构建镜像
demo = Composes('demo')
demo.version('3.9')
demo.services(image)
demo.build()

#!/usr/bin/python3
#-*- coding: utf-8 -*-
##############################################
# Home	: http://netkiller.github.io
# Author: Neo <[email protected]>
# Upgrade: 2021-11-17
##############################################
try:
	import os,  sys
	module = os.path.dirname(os.path.dirname(os.path.dirname(os.path.abspath(__file__))))
	print(module)
	sys.path.insert(0,module)
	from netkiller.docker import *
except ImportError as err:
	print("%s" %(err))

dockerfile = Dockerfile() 
# dockerfile.label({'org.opencontainers.image.authors':'netkiller'})
dockerfile.image('openjdk:8-alpine')
# dockerfile.image('openjdk:8')
dockerfile.env({'ROCKETMQ_VERSION':'4.9.2','ROCKETMQ_HOME':'/srv/rocketmq', 'PATH':'${ROCKETMQ_HOME}/bin:$PATH'}) # 'JAVA_OPT':'"${JAVA_OPT} -server -Xms512m -Xmx2048m -Xmn128m"'
dockerfile.arg({'user':'rocketmq', 'group':'nogroup'})
dockerfile.run('wget https://dlcdn.apache.org/rocketmq/4.9.2/rocketmq-all-4.9.2-bin-release.zip && unzip rocketmq-all-4.9.2-bin-release.zip')
dockerfile.run('mv rocketmq-4.9.2 /srv/rocketmq-4.9.2 && rm -rf rocketmq-all-4.9.2-bin-release.zip')
dockerfile.run('ln -s /srv/rocketmq-${ROCKETMQ_VERSION} /srv/rocketmq')
dockerfile.run('adduser -S -D ${user}')
dockerfile.run(['chown ${user}:${group} -R /srv/rocketmq-${ROCKETMQ_VERSION}'])
dockerfile.expose(['9876'])
dockerfile.expose(['10909','10911','10912'])
dockerfile.copy('docker-entrypoint.sh','/srv/docker-entrypoint.sh')
dockerfile.run('chmod a+x /srv/docker-entrypoint.sh')
dockerfile.entrypoint('["/srv/docker-entrypoint.sh"]') 
dockerfile.workdir('${ROCKETMQ_HOME}')
# dockerfile.render()
# dockerfile.save('/tmp/Dockerfile')

rocketmq = Services('rocketmq')
rocketmq.build(dockerfile).image('registry.netkiller.cn/rocketmq/rocketmq:4.9.2').container_name('rocketmq')
# rocketmq.entrypoint('/srv/rocketmq/bin/mqnamesrv')
# rocketmq.ports('9876:9876').command('/srv/rocketmq/bin/mqnamesrv')

dockerfile = Dockerfile() 
dockerfile.image('registry.netkiller.cn/rocketmq/rocketmq:4.9.2')
dockerfile.run('ln -s /srv/rocketmq-${ROCKETMQ_VERSION} /srv/mqnamesrv')
dockerfile.cmd('/srv/mqnamesrv/bin/mqnamesrv')
dockerfile.workdir('/srv/mqnamesrv')
dockerfile.user('rocketmq:nogroup')
dockerfile.volume([
 	'/home/rocketmq/logs/rocketmqlogs'
])

mqnamesrv = Services('mqnamesrv')
mqnamesrv.build(dockerfile).image('registry.netkiller.cn/rocketmq/mqnamesrv:4.9.2').container_name('mqnamesrv').ports('9876:9876')
mqnamesrv.command('mqnamesrv')

dockerfile = Dockerfile() 
dockerfile.image('registry.netkiller.cn/rocketmq/rocketmq:4.9.2')
dockerfile.run('ln -s /srv/rocketmq-${ROCKETMQ_VERSION} /srv/mqbroker')
dockerfile.cmd('/srv/rocketmq/bin/mqbroker')
dockerfile.workdir('/srv/mqbroker')
dockerfile.user('rocketmq:nogroup')
dockerfile.volume([
 	'/home/rocketmq/logs/rocketmqlogs'
])

mqbroker = Services('mqbroker')
mqbroker.build(dockerfile).image('registry.netkiller.cn/rocketmq/mqbroker:4.9.2').container_name('mqbroker').ports(['10909:10909','10911:10911','10912:10912'])
mqbroker.command('mqbroker -n mqnamesrv:9876 -c /srv/rocketmq/conf/broker.conf')
mqbroker.volumes(['/tmp/logs:/home/rocketmq/logs/rocketmqlogs'])

composes = Composes('test')
composes.version('3.9')
composes.services(rocketmq)
composes.services(mqnamesrv)
composes.services(mqbroker)


# cat >> /srv/docker-entrypoint.sh <<'EOF'
# EOF

entrypoint='''#!/bin/sh
if [ "$1" = 'mqnamesrv' ]; then
	exec /srv/rocketmq/bin/mqnamesrv
fi
exec "$@"
'''

if __name__ == '__main__':
	try:
		docker = Docker({'DOCKER_HOST':'ssh://[email protected]','NAMESRV_ADDR':'localhost:9876'}) 
		docker.createfile('rocketmq/rocketmq/docker-entrypoint.sh',entrypoint)
		docker.environment(composes)
		docker.main()
	except KeyboardInterrupt:
		print ("Crtl+C Pressed. Shutting down.")

python3 demo.py -e test -b rocketmq

快速入门，首先我们参照这个 docker-compose.yaml 脚本，转换成 python 脚本。

version: '3.9'	
services:
  nginx:
    container_name: nginx
    environment:
    - TZ=Asia/Shanghai
    extra_hosts:
    - db.netkiller.cn:127.0.0.1
    - cache.netkiller.cn:127.0.0.1
    - api.netkiller.cn:127.0.0.1
    hostname: www.netkiller.cn
    image: nginx:latest
    ports:
    - 80:80
    - 443:443
    restart: always
    volumes:
    - /tmp:/tmp

转换成 python 语言之后

from netkiller.docker import *

service =  Services('nginx')
service.image('nginx:latest')
service.container_name('nginx')
service.restart('always')
service.hostname('www.netkiller.cn')
service.extra_hosts(['db.netkiller.cn:127.0.0.1','cache.netkiller.cn:127.0.0.1','api.netkiller.cn:127.0.0.1'])
service.environment(['TZ=Asia/Shanghai'])
service.ports(['80:80','443:443'])
service.volumes(['/tmp:/tmp'])
# service.debug()
# print(service.dump())

compose = Composes('development')
compose.version('3.9')
compose.services(service)
# print (compose.debug())
print(compose.dump())
compose.save()

怎么样，只是换了另一种写法，并没有难度。下面我们就系统学习，如何使用 python 编排 docker 容器

实际上程序最终还是会转化做 docker-compose 脚本执行。这种写法的有点是更灵活，你可以在程序中使用 if, while, 链接数据库，等等操作，可以做更复杂的容器编排。

安装依赖库

neo@MacBook-Pro-Neo ~ % pip install netkiller-devops

确认是否安装成功

neo@MacBook-Pro-Neo ~ % pip show netkiller-devops
Name: netkiller-devops
Version: 0.2.4
Summary: DevOps of useful deployment and automation
Home-page: https://github.com/oscm/devops
Author: Neo Chen
Author-email: [email protected]
License: BSD
Location: /usr/local/lib/python3.9/site-packages
Requires: pyttsx3, requests, redis, pyyaml
Required-by:

创建一个 Services 

from netkiller.docker import *

service =  Services('nginx')
service.image('nginx:latest')
service.container_name('nginx')
service.restart('always')
service.hostname('www.netkiller.cn')
service.extra_hosts(['db.netkiller.cn:127.0.0.1','cache.netkiller.cn:127.0.0.1','api.netkiller.cn:127.0.0.1'])
service.environment(['TZ=Asia/Shanghai'])
service.ports(['80:80','443:443'])
service.volumes(['/tmp:/tmp'])
# service.debug()
print(service.dump())

nginx:
  container_name: nginx
  environment:
  - TZ=Asia/Shanghai
  extra_hosts:
  - db.netkiller.cn:127.0.0.1
  - cache.netkiller.cn:127.0.0.1
  - api.netkiller.cn:127.0.0.1
  hostname: www.netkiller.cn
  image: nginx:latest
  ports:
  - 80:80
  - 443:443
  restart: always
  volumes:
  - /tmp:/tmp

来一个复杂的演示

for i in range(10) :
    cluster =  Services('nginx-'+str(i))
    cluster.image('nginx:latest').container_name('nginx-'+str(i)).restart('always').hostname('www'+str(i)+'.netkiller.cn')
    cluster.ports(['8{port}:80'.format(port=i)])
    print(cluster.dump())

nginx-0:
  container_name: nginx-0
  hostname: www0.netkiller.cn
  image: nginx:latest
  ports:
  - 80:80
  restart: always

nginx-1:
  container_name: nginx-1
  hostname: www1.netkiller.cn
  image: nginx:latest
  ports:
  - 81:80
  restart: always

nginx-2:
  container_name: nginx-2
  hostname: www2.netkiller.cn
  image: nginx:latest
  ports:
  - 82:80
  restart: always

nginx-3:
  container_name: nginx-3
  hostname: www3.netkiller.cn
  image: nginx:latest
  ports:
  - 83:80
  restart: always

nginx-4:
  container_name: nginx-4
  hostname: www4.netkiller.cn
  image: nginx:latest
  ports:
  - 84:80
  restart: always

nginx-5:
  container_name: nginx-5
  hostname: www5.netkiller.cn
  image: nginx:latest
  ports:
  - 85:80
  restart: always

nginx-6:
  container_name: nginx-6
  hostname: www6.netkiller.cn
  image: nginx:latest
  ports:
  - 86:80
  restart: always

nginx-7:
  container_name: nginx-7
  hostname: www7.netkiller.cn
  image: nginx:latest
  ports:
  - 87:80
  restart: always

nginx-8:
  container_name: nginx-8
  hostname: www8.netkiller.cn
  image: nginx:latest
  ports:
  - 88:80
  restart: always

nginx-9:
  container_name: nginx-9
  hostname: www9.netkiller.cn
  image: nginx:latest
  ports:
  - 89:80
  restart: always

创建 Composes

Services 对象创建服务，让服务工作还需要 Composes 对象。

from netkiller.docker import *

service =  Services('nginx')
service.image('nginx:latest')
service.container_name('nginx')
service.restart('always')
service.hostname('www.netkiller.cn')
service.extra_hosts(['db.netkiller.cn:127.0.0.1','cache.netkiller.cn:127.0.0.1','api.netkiller.cn:127.0.0.1'])
service.environment(['TZ=Asia/Shanghai'])
service.ports(['80:80','443:443'])
service.volumes(['/tmp:/tmp'])

compose = Composes('development')
compose.version('3.9')
compose.services(service)
# print (compose.debug())
print(compose.dump())
compose.save()
# compose.save('/tmp/docker-compose.yaml')

services:
  nginx:
    container_name: nginx
    environment:
    - TZ=Asia/Shanghai
    extra_hosts:
    - db.netkiller.cn:127.0.0.1
    - cache.netkiller.cn:127.0.0.1
    - api.netkiller.cn:127.0.0.1
    hostname: www.netkiller.cn
    image: nginx:latest
    ports:
    - 80:80
    - 443:443
    restart: always
    volumes:
    - /tmp:/tmp
version: '3.9'

这已经是一个完善的 docker-compose 脚本了。使用 save 可以保存为 yaml 文件，这是使用 docker-compose -f development.yaml up 就可以启动容器了。

Composes 对象同时也携带了完善的 docker-compose 命令和参数，用于自我管理容器。

compose.up() 创建容器

compose = Composes('development')
compose.version('3.9')
compose.services(service)
compose.up()

compose.start() 启动已存在的容器

compose = Composes('development')
compose.version('3.9')
compose.services(service)
compose.start()

compose.stop() 停止已存在的容器

compose = Composes('development')
compose.version('3.9')
compose.services(service)
compose.stop()

compose.restart() 重启已存在的容器

compose = Composes('development')
compose.version('3.9')
compose.services(service)
compose.restart()

compose.rm() 销毁已存在的容器

compose = Composes('development')
compose.version('3.9')
compose.services(service)
compose.rm()

compose.logs() 查看容器日志

compose = Composes('development')
compose.version('3.9')
compose.services(service)
compose.logs()

compose.ps() 查看容器运行状态

compose = Composes('development')
compose.version('3.9')
compose.services(service)
compose.ps()

Docker 对象是让我们摆脱 docker-compose 这个命令，它将接管 docker-compose 这个命令，进行自我管理。

#!/usr/bin/python3
#-*- coding: utf-8 -*-
##############################################
# Home	: http://netkiller.github.io
# Author: Neo <[email protected]>
# Upgrade: 2021-09-05
##############################################
try:
	import os,  sys
	module = os.path.dirname(os.path.dirname(os.path.abspath(__file__)))
	sys.path.insert(0,module)
	from netkiller.docker import *
except ImportError as err:
	print("%s" %(err))

nginx =  Services('nginx')
nginx.image('nginx:latest')
nginx.container_name('nginx')
nginx.restart('always')
nginx.hostname('www.netkiller.cn')
nginx.environment(['TA=Asia/Shanghai'])
nginx.ports(['80:80'])

compose = Composes('development')
compose.version('3.9')
compose.services(nginx)
compose.workdir('/tmp/compose')

if __name__ == '__main__':
	try:
		docker = Docker()
		docker.environment(compose)
		docker.main()
	except KeyboardInterrupt:
		print ("Crtl+C Pressed. Shutting down.")

neo@MacBook-Pro-Neo ~ % python3 docker.py
Usage: docker.py [options] up|rm|start|stop|restart|logs|top|images|exec <service>

Options:
  -h, --help         show this help message and exit
  --debug            debug mode
  -d, --daemon       run as daemon
  --logfile=LOGFILE  logs file.
  -l, --list         following logging
  -f, --follow       following logging
  -c, --compose      show docker compose
  -e, --export       export docker compose

Homepage: http://www.netkiller.cn       Author: Neo <[email protected]>

Docker 对象提供了与 docker-compose 对等的参数，用法也基本相通。例如

python3 docker.py up = docker-compose up
python3 docker.py up -d nginx = docker-compose up -d nginx
python3 docker.py restart nginx = docker-compose restart nginx

python3 docker.py ps = docker-compose ps
python3 docker.py logs nginx = docker-compose logs nginx

使用 -c 可以查看 compose yaml 脚本，使用 -e 可以导出 docker compose yaml

Redis 主从配置

例 18.1. Redis Master/Slave

from netkiller.docker import *

image = 'redis:latest'
requirepass='11223344'

compose = Composes('redis-master-slave')
compose.version('3.9')

master =  Services('master')
master.image(image)
master.container_name('master')
master.restart('always')
master.environment(['TZ=Asia/Shanghai'])
master.ports('6379:6379')
master.volumes(['/tmp/master:/data'])
master.sysctls(['net.core.somaxconn=1024'])
master.command([
	'--requirepass '+requirepass,
	'--appendonly yes'])
# master.debug()
# print(master.dump())
compose.services(master)


for i in range(5) :
    slave =  Services('slave-'+str(i))
    slave.image(image).container_name('slave-'+str(i)).restart('always')
    slave.ports(['638{port}:6379'.format(port=i)]).environment(['TZ=Asia/Shanghai'])
    slave.volumes(['/tmp/slave{n}:/data'.format(n=i)])
    slave.sysctls(['net.core.somaxconn=1024']).command([
        '--slaveof master 6379',
        '--masterauth '+requirepass,
        '--requirepass ' + requirepass,
        '--appendonly yes'
    ])

    # print(cluster.dump())
    compose.services(slave)

# print (compose.debug())
print(compose.dump())
# compose.save()
compose.up()