django+tornado实现实时查看远程日志的方法

大致思路：

1.利用tornado提供的websocket功能与浏览器建立长连接，读取实时日志并输出到浏览器

2.写一个实时读取日志的脚本，利用saltstack远程执行，并把实时日志发往redis中。

3.tornado读取redis中的信息，发往浏览器。

此过程用到了redis的发布和订阅功能。

先看一下tornado中是如何处理的：

import os
import sys
import tornado.websocket
import tornado.web
import tornado.ioloop
import redis
import salt.client

from tornado import gen
from tornado.escape import to_unicode

from logs.utility import get_last_lines
from logs import settings


class SubWebSocket(tornado.websocket.WebSocketHandler):
 """
 此handler处理远程日志查看
 """
 def open(self, *args, **kwargs):
  print("opened")

 @gen.coroutine
 def on_message(self, message):
  # 主机名，要查看的日志路径，运行脚本的命令这些信息从浏览器传过来
  hostname, log_path, cmd = message.split("||")
  local = salt.client.LocalClient()
  r = redis.StrictRedis(host=settings.REDIS_HOST, port=settings.REDIS_PORT,
        password=settings.REDIS_PASSWD, db=5)
  # 订阅频道，服务器和日志路径确定一个频道
  key = settings.LOG_KEY.format(server=hostname.strip(), log_path=log_path.strip())
  channel = r.pubsub()
  channel.subscribe(key)
  # 异步方式执行命令，远程运行脚本
  local.cmd_async(hostname, "cmd.run", [cmd])
  try:
   while True:
    data = channel.get_message()
    if not data:
     # 如果读取不到消息，间隔一定时间，避免无谓的CPU消耗
     yield gen.sleep(0.05)
     continue
    if data["type"] == "message":
     line = format_line(data["data"])
     self.write_message(line)
  except tornado.websocket.WebSocketClosedError:
   self.close()

 def on_close(self):
  global FLAG
  FLAG = False
  print("closed")


def format_line(line):
 line = to_unicode(line)
 if "INFO" in line:
  color = "#46A3FF"
 elif "WARN" in line:
  color = "#FFFF37"
 elif "ERROR" in line:
  color = "red"
 elif "CRITICAL" in line:
  color = "red"
 else:
  color = "#FFFFFF"

 return "<span style='color:{}'>{}</span>".format(color, line)


class EchoWebSocket(tornado.websocket.WebSocketHandler):
 def open(self):
  print("WebSocket opened")

 @gen.coroutine
 def on_message(self, message):
  log = message
  print "log file: ", log

  try:
   with open(log, 'r') as f:
    for line in get_last_lines(f):
     line1 = format_line(line)
     self.write_message(line1)
    while True:
     line = f.readline()
     if not line:
      yield gen.sleep(0.05)
      continue
     self.write_message(format_line(line.strip()))
  except tornado.websocket.WebSocketClosedError as e:
   print e
   self.close()

 # def check_origin(self, origin):
 #  print origin, self.request.headers.get("Host")
 #  # super(EchoWebSocket, self).check_origin()
 #  return True

 def on_close(self):
  print("WebSocket closed")


class Application(tornado.web.Application):
 def __init__(self):
  handlers = [
   (r'/log/', MainHandler), # 提供浏览页面，页面中的JS与服务器建立连接
   (r'/log/local', EchoWebSocket), # 处理本地日志实时查看，比较简单
   (r'/log/remote', SubWebSocket), # 处理远程日志实时查看，稍微复杂
  ]
  settings = {
   "debug": True,
   "template_path": os.path.join(os.path.dirname(__file__), "templates"),
   "static_path": os.path.join(os.path.dirname(__file__), "static"),
  }
  super(Application, self).__init__(handlers, **settings)


class MainHandler(tornado.web.RequestHandler):
 def get(self):
  # 要查看的日志路径
  log = self.get_argument("log", None)
  # hostname实际上是saltstack中这台机器对应的minion id
  hostname = self.get_argument("hostname", None)
  # 本地日志还是远程日志
  type = self.get_argument("type", "local")
  # 运行读取实时日志的脚本，参数比较多，后面会有
  cmd = self.get_argument("cmd", "")
  context = {
   "log": log,
   "hostname": hostname,
   "type": type,
   "cmd": cmd,
  }
  self.render("index.html", **context)

配置文件中主要记录了redis服务器的地址等信息

# encoding: utf-8

LOG_KEY = "logs:{server}:{log_path}"

LOG_NAME = "catalina.out"
TAIL_LINE_NUM = 20

REDIS_HOST = "127.0.0.1"
REDIS_PORT = "6379"
REDIS_PASSWD = None
REDIS_EXPIRE = 300

try:
 from local_settings import *
except ImportError:
 pass

index.html的内容如下：

<html>
<head>
<link href="{{ static_url('public/css/public.css') }}" rel="external nofollow" rel="stylesheet" />
<link href="{{ static_url('kylin/css/style.css') }}" rel="external nofollow" rel="stylesheet" />
</head>
<body style="background:#000000">
<div style="margin-left:10px;">
 <pre id="id-content">
 </pre>
 <div id="id-bottom"></div>
 <input type="hidden" id="id-log" value="{{ log }}" />
 <input type="hidden" id="id-type" value="{{ type }}" />
 <input type="hidden" id实现优雅退出循环
    line = f.readline()
    if not line:
     time.sleep(0.05)
     continue
    process_line(r, channel, line)
  except KeyboardInterrupt:
   pass
 print("Exiting...")

if __name__ == "__main__":
 if len(sys.argv) < 6:
  print "Usage: %s minion_id log_path host port redis_pass"
  exit(1)

 tail()

到此为止，整个实时读取远程日志的流程就讲完了。

github: https://github.com/tuxinhang1989/logs

以上这篇django+tornado实现实时查看远程日志的方法就是小编分享给大家的全部内容了，希望能给大家一个参考，也希望大家多多支持社区。