利用python自動生成docker nginx反向代理配置

由于在測試環境上用docker部署了多個應用，而且他們的端口有的相同，有的又不相同，數量也比較多，在使用jenkins發版本的時候，不好配置，于是想要寫一個腳本，能在docker 容器創建、停止的時候，自動生成nginx反向代理，然后reload nginx

我的原則是盡量簡單，輕量，內存占用少

目標很明確，只要能監聽到docker的容器啟動/停止事件，即可

網上查了一下可以用docker events來監聽docker事件，試了一下，發現基本可以滿足，于是用python寫了一段程序，用來監聽docker事件

python

#!/usr/bin/python# coding: utf8import osimport jsonimport reimport subprocessdef 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 retdef 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 rettpl = """  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