由于在测试环境上用docker部署了多个应用，而且他们的端口有的相同，有的又不相同，数量也比较多，在使用jenkins发版本的时候，不好配置，于是想要写一个脚本，能在docker 容器创建、停止的时候，自动生成nginx反向代理，然后reload nginx

我的原则是尽量简单，轻量，内存占用少

目标很明确，只要能监听到docker的容器启动/停止事件，即可

网上查了一下可以用docker events来监听docker事件，试了一下，发现基本可以满足，于是用python写了一段程序，用来监听docker事件

python

#!/usr/bin/python

# coding: utf8

import os

import json

import re

import subprocess

def override(path, text):

    if not os.path.exists(path) and os.path.exists(path+"_temp"):

        os.rename(path+"_temp",path)

    fw = open(path+"_temp", 'wb')

    fw.write(text)

    fw.close()

    if os.path.exists(path):

        os.remove(path)

    os.rename(path+"_temp", path)

def read(path):

    try:

        fr = open(path, "rb")

    except IOError:

        print "The file don't exist, Please double check!"

        return

    lines = fr.readlines()

    ret = ''

    for line in lines:

        ret += line

    return ret

def read_jsonfile(path):

    return json.loads(read(path))

def cmd(command):

    return os.popen(command).read()

def get_name(container):

    return cmd("docker inspect -f '{{.Name}}' " + container).replace("/", "").replace('\n', '')

def get_ip(container):

    return cmd("docker inspect -f '{{.NetworkSettings.IPAddress}}' " + container).replace('\n', '')

def get_port(container):

    return cmd("docker inspect -f '{{.Config.ExposedPorts}}' " + container).replace('/tcp:{}]', '').replace('map[', '').replace('\n', '')

def get_info(container):

    filename = "/var/lib/docker/containers/" + container + "/config.v2.json"

    config = read_jsonfile(filename)

    name = config['Name'].replace("/", "")

    port = config['Config']['ExposedPorts'].keys()[0].replace('/tcp', '')

    ip = cmd("docker inspect -f '{{.NetworkSettings.IPAddress}}' " + name)

    # ip = config['NetworkSettings']['Networks']['bridge']['IPAddress']

    ret = {'name': name, 'port': port, 'ip': ip}

    return ret

tpl = """

    server {

        listen 80;

        server_name $name.test.com;

        location / {

	    proxy_set_header X-Real-IP $remote_addr;

            proxy_set_header Host $http_host;

            proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;

            proxy_pass http://$ip:$port;

        }

    }

"""

def generate_conf():

    print "generate_conf"

    out = cmd("docker ps | grep -v CONTAINER | awk '{print $1}'")

    containers = out.split("\n")

    servers = ''

    hosts = ''

    for con in containers:

        if con != '':

            name = get_name(con)

            ip = get_ip(con)

            port = get_port(con)

            print ip, port

            if len(port) >= 2:

                servers += tpl.replace("$name", name).replace("$ip", ip).replace("$port", port)

                hosts += "11.12.13.14 " + name + ".test.com\n"

    override('/usr/local/openresty/nginx/conf/vhost.conf', servers)

    override('/usr/local/openresty/nginx/html/vhost.html', "<pre>" + hosts + "</pre>")

def reload_nginx():

    print "reload nginx"

    cmd('nginx -s reload')

def auto_reload():

    generate_conf()

    reload_nginx()

print " ==================== docker events ==================== "

# auto_reload()

proc = subprocess.Popen(["docker", "events"],

                        # shell=True,   # windows: true, linux: false

                        stdout=subprocess.PIPE)

while 1:

    out = proc.stdout.readline()

    event = re.sub('\(|\)', "", out).split(" ")

    if out.find('container stop') != -1:

        auto_reload()

        print ' container stop '

    elif out.find('container start') != -1:

        auto_reload()

        print ' start container '

    if out == '':

        print "out "

        break

启动命令：

nohup ./docker.py > /dev/null 2>&1 &

程序会在后台运行，断开ssh也不会结束

主要就是生成一个 conf 文件，这个文件要在nginx.conf里面引入，然后每次有容器启动/停止都生成这个文件，然后重启nginx，我这了还把容器名加上一个域名，组合成了一个子域名，然后把对应的映射关系生成了一个html文件，通过浏览器可以访问这个文件，然后把对应的代码 复制到本机的 hosts 文件里面，可以实现通过域名访问应用，当然只是开发测试的时候会这么做，但是也足够了。