User:Darien Caldwell/HTTP-DNS Code

dns.py File

<python> import urllib import webapp2 from google.appengine.ext import db

class Service(db.Model):

 name = db.StringProperty(multiline=False)
 url = db.StringProperty(multiline=False)
 

class MainPage(webapp2.RequestHandler):

 def get(self):

    if self.request.get('type')=='add':  # Adding a new service to the DNS (You can also use Update but it won't tell you the service already exists)
         param2=self.request.get('name') #the Name the service will be known by         
         param3=self.request.get('url') # the URL for the web service
         q = db.GqlQuery("SELECT * FROM Service WHERE name = :kk",kk=param2)
         count=q.count(2)

         if count==0 :  # the service doesn't exist, so add it.
             if param2=="" or param3=="" :
                 self.response.out.write('Error2')
             else:
                 newrec=Service(name=param2,url=param3)
                 newrec.put()
                 self.response.out.write('Added')
         else:
             self.response.out.write('Found')  # service already exists so announce that and do nothing
             
    elif self.request.get('type')=='remove': #removing a service
         param2=self.request.get('name')	 # the name the service is known by
         q = db.GqlQuery("SELECT * FROM Service WHERE name = :kk",kk=param2)
         count=q.count(2)

         if count==0 :
           self.response.out.write('None') # Service wasn't found
         else:
           results=q.fetch(10)            
           db.delete(results)  # remove them all (just in case some how, some way, there is more than one service with the same name 
           self.response.out.write('Removed')
           
    elif self.request.get('type')=='update':  # update an existing service. Note this creates a new service, or updates an existing one
         param2=self.request.get('name') #the Name the service will be known by         
         param3=self.request.get('url') # the URL for the web service
         q = db.GqlQuery("SELECT * FROM Service WHERE name = :kk",kk=param2)
         count=q.count(2)

         if count!=0 :  # if record already exists, remove it
               results=q.fetch(10)            
               db.delete(results)  # remove them all (just in case some how, some way, there is more than one service with the same name
         if param2=="" or param3=="" :
             self.response.out.write('Error2')
         else:
             newrec=Service(name=param2,url=param3) # add record, either replacing the deleted one, or adding a new one if it never existed
             newrec.put()
             if count!=0 : 
                 self.response.out.write('Updated')
             else:
                 self.response.out.write('Added')
           
    elif self.request.get('type')=='retrieve': # get the current URL for a given service
         param2=self.request.get('name')	 # the name the service is known by
         q = db.GqlQuery("SELECT * FROM Service WHERE name = :kk",kk=param2)
         count=q.count(2)
         if count==0 :
               self.response.out.write('None') # Service wasn't found
         else:
               record=q.get()
               self.response.out.write(record.url) #print the URL
    elif self.request.get('type')=='list': # List the existing services
         q = db.GqlQuery("SELECT * FROM Service" )
         count=q.count()

         if count==0 :
             self.response.out.write('Empty') # Services weren't found
         else: 
             results = q.fetch(1000)
             for result in results:      
                self.response.out.write(result.name+',')
             self.response.out.write('END')  # Cap the list             

    else: self.response.out.write('Error')

class Redirector(webapp2.RequestHandler):

 def get(self):
   service_name=self.request.path
   if service_name[-1]=='/' :
     service_name=service_name[1:-1] #remove leading and trailing slash
   else:
     service_name=service_name[1:]  # remove leading slash only
     
   #un-escape just in case you're Kinki :p
   service_name=urllib.unquote(service_name)
 
   q = db.GqlQuery("SELECT * FROM Service WHERE name = :kk",kk=service_name)
   count=q.count(2)
   if count==0 :
     self.response.out.write('None') # Service wasn't found
   else:
     record=q.get()  #get the URL we stored previously

     if self.request.query_string !=  :
       self.redirect(urllib.unquote(record.url)+'?'+self.request.query_string) # redirect to the HTTP-IN URL with arugments
     else:        
       self.redirect(urllib.unquote(record.url)) # redirect to the HTTP-IN URL
     

app = webapp2.WSGIApplication( [('/', MainPage),

                               ('/.*',Redirector)],
                               debug=True)

</python>

app.yaml File

<text> application: YOUR-APP-NAME-HERE version: 1 runtime: python27 api_version: 1 threadsafe: true

handlers: - url: /.*

 script: dns.app

</text>