[虚拟化/云][全栈demo] 为qemu增加一个PCI的watchdog外设（八）

时间：2014-07-08 11:49:31 阅读：189 评论：0 收藏：0 [点我收藏+]

标签：des style blog http java color

目的：

1. 通过网页读取watchdog的信息

2. 通过网页设置watchdog

准备工作：

1. 选择一个web框架，选用 cherrypy

$ sudo apt-get install python-cherrypy3

2. 熟悉 RESTFUL ，参考redhat REST API 指导

步骤：

我们选择了一个cherrypy作为web框架。 cherrypy的部署简单。

这只是个demo，没有实现MVC，大家自己练习。

此外也没有实现模板，距离一个正式的网站还差的很远。

界面实现如下：

bubuko.com,布布扣

代码如下：

代码中，喂狗代码采用了一个线程。需要改进。

发现不是很好，因为每个wsgi的请求都是一个线程。

最好是采用cherrypy提供的background，或者将该逻辑独立为一个单例模式。

watchdog.py

  1     import cherrypy
  2     import json
  3     import time
  4     import threading
  5      
  6      
  7     index_html = """
  8     <html>
  9     <head>
 10     <style type="text/css">
 11     .watchdog-state {
 12         display: inline-block;
 13         height: 16px;
 14         width: 16px;
 15         border-radius: 8px;
 16         margin-left: 10px;
 17         margin-right: 10px;
 18     }
 19     .up {
 20         background: linear-gradient(to bottom, #BFD255 0%%, #8EB92A 50%%,
 21                     #72AA00 51%%, #9ECB2D 100%%) repeat scroll 0 0 transparent;
 22     }
 23      
 24     .down {
 25         background: linear-gradient(to bottom, #AFAFAF 0%%, #AFAFAF 50%%,
 26                     #AFAFAF 51%%, #AFAFAF 100%%) repeat scroll 0 0 transparent;
 27     }
 28     </style>
 29     </head>
 30      
 31     <body>
 32     <script type="text/javascript">
 33         function requestJSON(url, suc, done, err) {
 34             var xmlhttp;
 35             xmlhttp = new XMLHttpRequest();
 36             xmlhttp.open("POST", url, true);
 37             xmlhttp.setRequestHeader("Content-type", "application/json");
 38             xmlhttp.setRequestHeader("dataType", "application/json");
 39             xmlhttp.onreadystatechange=function(){
 40                 if (xmlhttp.readyState==4 && xmlhttp.status==200) {
 41                     var responseContext = xmlhttp.responseText;
 42                     var jsonobj=eval(‘(‘+responseContext+‘)‘);
 43                     suc(jsonobj);
 44                 } else{
 45                     // alert("readyState: " + xmlhttp.readyState + "status" + xmlhttp.status);
 46                 }
 47             }
 48             xmlhttp.send();
 49         }
 50      
 51         function operationWatchdog()
 52         {
 53             // alert("operationWatchdog");
 54             var url = "watchdog/deactivate";
 55             var action = document.getElementById("watchdog-action");
 56             if (action.innerHTML == "Activate"){
 57                 url = "watchdog/activate";
 58             }
 59             requestJSON(url, function(data){
 60                 // alert(data.value);
 61             });
 62             if (action.innerHTML == "Activate"){
 63                 action.innerHTML = "Deactivate";
 64             } else {
 65                 action.innerHTML = "Activate";
 66             }
 67             var status = document.getElementById("watch-status");
 68             if (status.className.match("up$")){
 69                 status.className = "watchdog-state down";
 70             } else{
 71                 status.className = "watchdog-state up";
 72             }
 73         }
 74         function FeedWatchod()
 75         {
 76             // alert("FeedWatchod");
 77             var url = "watchdog/feedstop";
 78             var feed = document.getElementById("feed-watchdog");
 79             if (feed.innerHTML == "Start"){
 80                 url = "watchdog/feedstart";
 81             }
 82             requestJSON(url, function(data){
 83                 //alert(data.value);
 84             });
 85             if (feed.innerHTML == "Start"){
 86                 feed.innerHTML = "Stop";
 87             } else {
 88                 feed.innerHTML = "Start";
 89             }
 90         }
 91     </script>
 92         <div>
 93             Status of watchdog: <span id="watch-status" class="watchdog-state %s"> </span>
 94             <button id="watchdog-action" type="button" onclick="operationWatchdog()">%s</button>
 95         </div>
 96         <div>
 97             Feed watchdog:
 98             <button id="feed-watchdog" type="button" onclick="FeedWatchod()">Start</button>
 99         </div>
100     </body>
101     </html> """
102      
103     def jsonObj(data):
104         cherrypy.response.headers[‘Content-Type‘] = ‘application/json;charset=utf-8‘
105         return json.dumps(data, indent=2, separators=(‘,‘, ‘:‘))
106      
107     watchdog_hadle = open("/dev/cwd_demo", "w+")
108     def watchdogStatus():
109         vals = watchdog_hadle.readlines();
110         return vals[0] == [‘B\x01\n‘]
111      
112     def watchdogAction(action):
113         watchdog_hadle.write(action)
114         watchdog_hadle.flush()
115      
116     class WelcomePage(object):
117         def __init__(self):
118             self.watchdog = Watchdog()
119      
120         def index(self):
121             watchdog_state = "down"
122             watchdog_action = "Activate"
123             if watchdogStatus():
124                 watchdog_state = "up"
125                 watchdog_action = "Deactivate"
126             a = index_html % (watchdog_state, watchdog_action)
127             print a
128             return a
129         index.exposed = True
130      
131      
132         def default(*args, **kwargs):
133             data = {"hello": "world"}
134             return jsonObj(data)
135         default.exposed = True
136      
137      
138      
139     class Watchdog(object):
140         exposed = True
141         feed_running = False
142         feed_thread = None
143      
144         def __init__(self):
145             pass
146      
147         @classmethod
148         def worker(cls):
149             while cls.feed_running:
150                  print "worker"
151                  watchdogAction(‘t‘)
152                  time.sleep(1)
153             return
154      
155         @cherrypy.expose
156         def index(self, *args, **kwargs):
157             data = {"value": False}
158             data = {"value": watchdogStatus()}
159             return jsonObj(data)
160      
161         @cherrypy.tools.accept(media=‘application/json‘)
162         @cherrypy.expose
163         def activate(self, *args, **kwargs):
164             watchdogAction(‘a‘)
165             print "activate"
166             raise cherrypy.InternalRedirect("/watchdog")
167      
168         @cherrypy.tools.accept(media=‘application/json‘)
169         @cherrypy.expose
170         def deactivate(self, *args, **kwargs):
171             watchdogAction(‘d‘)
172             print "deactivate"
173             raise cherrypy.InternalRedirect("/watchdog")
174            
175         @cherrypy.tools.accept(media=‘application/json‘)
176         @cherrypy.expose
177         def feedstart(self, *args, **kwargs):
178             watchdogAction(‘t‘)
179             print "feed start"
180             if self.__class__.feed_thread == None:
181                 self.__class__.feed_thread = threading.Thread(
182                     target=self.__class__.worker)
183             if self.__class__.feed_running == False:
184                 self.__class__.feed_running = True
185                 self.__class__.feed_thread.start()
186             raise cherrypy.InternalRedirect("/watchdog")
187      
188         @cherrypy.expose
189         def feedstop(self, *args, **kwargs):
190             print "feed stop"
191             if self.__class__.feed_thread.isAlive():
192                 self.__class__.feed_running = False
193                 self.__class__.feed_thread.join(1.5)
194                 self.__class__.feed_thread = None
195             raise cherrypy.InternalRedirect("/watchdog")
196      
197     if __name__ == ‘__main__‘:
198         # CherryPy always starts with app.root when trying to map request URIs
199         # to objects, so we need to mount a request handler root. A request
200         # to ‘/‘ will be mapped to HelloWorld().index().
201         cherrypy.quickstart(WelcomePage())
202     else:
203         # This branch is for the test suite; you can ignore it.
204         cherrypy.tree.mount(WelcomePage())

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[虚拟化/云][全栈demo] 为qemu增加一个PCI的watchdog外设（八）,布布扣,bubuko.com

[虚拟化/云][全栈demo] 为qemu增加一个PCI的watchdog外设（八）

标签：des style blog http java color

原文地址：http://www.cnblogs.com/shaohef/p/3819382.html

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