Unified XML and JSON RPC Dispatcher for Django

Posted on June 26, 2009 by David

After looking around at the rpc support available in Django, I think I will create and distribute my own application. Here are the goals:

Complete xml and json rpc support
Easy identification of rpc methods by a decorator
Customizable documentation (which is absent from DocXMLRPCServer)
Support rpc introspection
Support for method signatures (which is absent from SimpleXMLRPCServer)
Easy installation and integration into Django projects
Licensed properly for open source or commercial software

Updates to come. I’m off to San Francisco for a weekend of fun.

Django with JsonRPC and XMLRPC

Posted on June 4, 2009July 14, 2009 by David

[Edit: take a look at RPC4Django for a JSONRPC and XMLRPC server for Django]

I corresponded recently with a developer working on a Django-powered jsonrpc library. In the past, I have done some work on web applications that require good external interfaces. In some cases, however, it makes sense to make the same methods available via both jsonrpc and xmlrpc.

For javascript and flash, json makes a lot of sense. For communication between client side and server side, jsonrpc works very well since json is natively supported and speed can be more of a factor in presentation. However, if external interfaces are also going to interact with your API, jsonrpc is not as well supported as xmlrpc. Virtually every language has good libraries for xmlrpc. For this reason, it makes good sense to combine the two and make the same methods available to both.

import logging
from SimpleXMLRPCServer import SimpleXMLRPCDispatcher
from django.http import HttpResponse, Http404
from jsonrpc import JsonRpc

xmlrpcdispatcher = SimpleXMLRPCDispatcher(allow_none=False, encoding=None)
jsonrpcdispatcher = JsonRpc()
# ... register methods with xmlrpc and jsonrpc

def rpc_handler(request):
    if request.META['CONTENT_TYPE'] == 'application/json':
        response = jsonrpcdispatcher.handle_request(request)
    elif request.META['CONTENT_TYPE'] == 'text/xml':
        response = HttpResponse()
        response.write(xmlrpcdispatcher._marshaled_dispatch(request.raw_post_data))
        response['Content-length'] = str(len(response.content))
    else:
        # display documentation, or just raise a 404
        logging.debug('rpc request type: %s' %request.META['CONTENT_TYPE'])
        raise Http404

    return response

import logging

from SimpleXMLRPCServer import SimpleXMLRPCDispatcher

from django.http import HttpResponse, Http404

from jsonrpc import JsonRpc

xmlrpcdispatcher = SimpleXMLRPCDispatcher(allow_none=False, encoding=None)

jsonrpcdispatcher = JsonRpc()

# ... register methods with xmlrpc and jsonrpc

def rpc_handler(request):

if request.META['CONTENT_TYPE'] == 'application/json':

response = jsonrpcdispatcher.handle_request(request)

elif request.META['CONTENT_TYPE'] == 'text/xml':

response = HttpResponse()

response.write(xmlrpcdispatcher._marshaled_dispatch(request.raw_post_data))

response['Content-length'] = str(len(response.content))

else:

# display documentation, or just raise a 404

logging.debug('rpc request type: %s' %request.META['CONTENT_TYPE'])

raise Http404

return response

Subversion Backups via Email

Posted on May 30, 2009May 30, 2009 by David

I wrote a simple subversion backup script that runs on my hosting provider, webfaction, and backs up my subversion repository. I have this script running in cron and sending periodic backups to gmail. However, it should work on any unix based system with python, gzip, and subversion. Simply set the SMTP settings (configured in the webfaction panel if you have webfaction), your email information and the path to subversion and run the script.

This script requires python 2.5 or 2.6. It will require modification under python 2.4.


!/usr/bin/env python2.6

import os
import smtplib
import time
import mimetypes
from datetime import datetime

# python 2.5/2.6 is required because the email library changed after 2.4
from email import encoders
from email.mime.multipart import MIMEMultipart
from email.mime.base import MIMEBase

# SMTP settings
SMTPUSER = 'YOURSMTPUSERNAME'
SMTPPASS = 'YOURSMTPPASSOWRD'
SMTPSERVER = 'smtp.webfaction.com'
SMTPPORT = 25

# who to address the email to and from
TO = 'YOUREMAIL@EXAMPLE.com'
FROM = 'backups@webfaction.com'

# svn location
SVN_LOCATION = 'PATH_TO_SVN_DIR'

# these probably do not need to be changed
SVN_BACKUP_FILE = 'svn.dump'
GZIP_BACKUP_FILE = SVN_BACKUP_FILE + '.gz'
BACKUP_LOCATION = '/tmp/'+SVN_BACKUP_FILE
ZIPPED_BACKUP = BACKUP_LOCATION+'.gz'
BACKUP_CMD = 'svnadmin dump '+SVN_LOCATION+' &gt; ' + BACKUP_LOCATION
GZIP_CMD = 'gzip -f '+BACKUP_LOCATION

print '*******************************************************'
print '** Backing up repository'
print '*******************************************************'
os.system(BACKUP_CMD)

print '*******************************************************'
print '** Zipping backup'
print '*******************************************************'
os.system(GZIP_CMD)

print '*******************************************************'
print '** Emailing backup'
print '*******************************************************'
msg = MIMEMultipart()
msg['Subject'] = 'Subversion Backup '+str(datetime.now())
msg['From'] = FROM
msg['To'] = list().append(TO)
msg.preample = 'Should not see this in a MIME-aware mail reader.\n'

# add the gzipped attachment
fp = open(ZIPPED_BACKUP, 'rb')
att = MIMEBase('application', 'gzip')
att.set_payload(fp.read())
encoders.encode_base64(att)
att.add_header('Content-Disposition', 'attachment', filename=GZIP_BACKUP_FILE)
fp.close()
msg.attach(att)

# Send the email via our own SMTP server.
s = smtplib.SMTP(SMTPSERVER, SMTPPORT)
s.ehlo()
s.starttls()
s.ehlo()
s.login(SMTPUSER, SMTPPASS)
s.sendmail(FROM, TO, msg.as_string())
s.quit()

# removing backup
os.remove(ZIPPED_BACKUP)

!/usr/bin/env python2.6

import os

import smtplib

import time

import mimetypes

from datetime import datetime

# python 2.5/2.6 is required because the email library changed after 2.4

from email import encoders

from email.mime.multipart import MIMEMultipart

from email.mime.base import MIMEBase

# SMTP settings

SMTPUSER = 'YOURSMTPUSERNAME'

SMTPPASS = 'YOURSMTPPASSOWRD'

SMTPSERVER = 'smtp.webfaction.com'

SMTPPORT = 25

# who to address the email to and from

TO = 'YOUREMAIL@EXAMPLE.com'

FROM = 'backups@webfaction.com'

# svn location

SVN_LOCATION = 'PATH_TO_SVN_DIR'

# these probably do not need to be changed

SVN_BACKUP_FILE = 'svn.dump'

GZIP_BACKUP_FILE = SVN_BACKUP_FILE + '.gz'

BACKUP_LOCATION = '/tmp/'+SVN_BACKUP_FILE

ZIPPED_BACKUP = BACKUP_LOCATION+'.gz'

BACKUP_CMD = 'svnadmin dump '+SVN_LOCATION+' > ' + BACKUP_LOCATION

GZIP_CMD = 'gzip -f '+BACKUP_LOCATION