django beginner book... uses mod_wsgi - django

I notice that the official recommended book "The Definitive Guide to Django" was written based on mod_python, for both editions.
However, I think most beginners would follow what most people use: mod_wsgi.
I followed their first tutorials, that is, display current time
I have the mod_wsgi and everything setup correctly. But I am still getting the default page regardless how I access to http://domain/time/
Is there any book that is written for mod_wsgi, or did t setup the environment incorrectly?
I know I can begin without using apache, but it would be a headache in the future to deploy apache again...
EDIT
I added the wsgi script and inclued that in the views.py. It seems to work. Is it the right way???
So what is the purpose of having a separate wsgi script anyway?
I know the official guide said that create a folder name such as /apache/ and create django.wsgi...

You don't need a full rewrite of the Django book for mod_wsgi. The ony thing that is different is the apache.conf and the script inside your cgi-bin directory (both aren't directly related to Django, so all the Django parts will apply for both).
But you might probably find it useful to read the general usage/configuration instructions for mod_wsgi, and probably the special notes about django too. If you have some troubles (e.g. some kind of error message in your apache.log) then you might look at the ConfigurationIssues page too.
So what is the purpose of having a separate wsgi script anyway?
Nearly all Python web applications are based on the WSGI specification, which allows your application to be used with CGI, FastCGI, mod_python, mod_wsgi, etc. So, you might have more than one of those scripts - one for each technology for example.
Another thing is, that you can also control a lot of configuration settings inside this script (e.g. forking of additional python processes for increased performance, path to additional python modules or different versions of existing modules) which are normally set by the server administrator (and not the application developer). Thats probably also the main reason why such scripts aren't included directly in the applications.
And the third thing is, that you might have several such wsgi scripts which are deploying the same application with different settings. For example, you might have your application deployed several times for different users, or with different database settings (e.g. production and testing).

Related

How to deploy django server into production environment without a full source code?

I am still a newbie to Python and Django. I am developing a application using Django which will eventually go to the production server. It's a customized web application for the client. After doing some research, I found out Apache with mod_wsgi is the best option for Django deployment. I just have to copy and paste the code into the production server and the application is accessible. But what if I don't want to give the whole source code and give only the executable application to the client(P.S client wants to deploy the application to their own server). Is something like this possible in Python/Django?
You could only give them the .pyc files corresponding to your source code files. That will make it slightly harder for them to look at your source code. However, it's a very limited measure (i.e. they can still recover some of the structure from your source code), and it's probably a bad idea.

Idiots guide to getting a django project onto the web please

Help! I think i've gone in a bit over my head. I'm making a website for a friend who has already got a domain/hosting on the website 123reg. Keen to learn them i've been picking up python and django as i go, figured getting it online would be no problem because 123reg supports python (unspecified version).
So far i've been doing everything with the django test-server locally, i went to look into uploading it somewhere as a test and realised there's an awful lot i don't know and even with google its a bit overwhelming.
I found this link which will help me later i'm sure but right now, could someone help me understand What is Apache? I thought the server was the hardware a site was physically hosted on but i can't understand it at all now.. So i download Apache and then what? Can i just copy it into the root directory for the website on 123reg? Is their an installer? Will 123reg allow it to "run" or "serve" or whatever word's appropriate or will there be permissions issues?
And then once that's sorted there's mod_wsgi to look into, a cursory glance at the installation guide shows commands to be run, which confuses me further as i was not aware that a standard host like 123reg have any sort of inbuilt console window to be run on in which case how are you expected to execute these commands?
And another thing I didn't really think through, I'm using the built in sqlite database technology.. How will i be able to install it on my webspace? and then how will that effect my django configuration? or maybe i'll have to change to MySql v5 which 123reg says it supports?
I know these must be idiotic questions, I just wasn't sure where best to ask for help and SO has one of the most helpful and knowledgeable communities around. I did try having a google but everything was a bit overly technical for me.
You can't upload a Django site using FTP on a shared hosting provider and expect it to run. You'll need to configure it to run with their installed Apache, including configuration like mod_wsgi.
I very much doubt that 123-reg support this. You are unlikely to be able to run a Django site there. You should look for a more Django-friendly site - I recommend Webfaction.
Apache is the webserver software. It's already running on their machines. Don't try and install it lol, or they will certainly laugh at you.
To "run commands" you need to get a remote shell (console). This is typically done via Secure Shell (SSH). See this page regarding 123reg specifically: How do I connect using SSH (Putty)?
Django supports different databases, including SQLite and MySQL. SQLite is typically for small, simple databases, as the "database" is really just a local file that is manipulated by the SQLite engine. MySQL is the database of choice for many websites.

Modifying existing Django site

I am completely new to this Django world. I haven't tried it ever before.
Now the problem is as below;
One of my clients was hosting his site somewhere else that I don't know and they built the site using Django. The host company doesn't allow to make any changes on their server, instead they provided the zip file for all the files in the site to me; so that now I can host my client's site.
As I don't know anything about Django, can someone please shed a light where I should start from?
Thanks in advance.
Cheers.
Sach
First of all, install Django on the development machine. Start by trying to get the development server run on your machine.
Gather requirements: check the settings.py for installed apps against the default Django settings.py file. See if there are any popular django apps that site depends on. If there are any, then you probably will have to install them, too.
In which format was the database provided? Will you move to another more appropriate format? Python bindings for databases are required too.
Considering the fact that you have inherited this project and probably will need to make some changes, consider installing django-south, so you can easily make changes to the database schema.
If you get the site running properly on your own machine, consider deplyoment. Is there a lot of static content? (if so, consider nginx). Set up apache2 and install the mod_wsgi module. Deploy.
Work your way through the Django tutorial first. Then look into Django Book as has been mentioned. Django IRC channel (#django) on Freenode is also great for help.
Your best bet would be to learn about Django before trying to jump in head first - https://www.djangoproject.com/ contains documentation as well as tutorials on creating Django apps.
Django is fairly easy to setup if you already have the code written. You'll need to install the chosen database and then simply follow the tutorial on the Django website
Django comes with a built-in server so it's very easy to run the website for development without needing Apache, nginx or much else.
I learned using the Django Book. Django is an easy-to-use framework, you should be fine.
Also, in the short-term there's a file called views.py and separate folder containing templates. If you're familiar with MVC (MVT in Django) this contains the views for the site in function form. There's probably (but not always) a folder for templates which contains a lot of the HTML for the site. Just a good starting pointing for basic modifications.
You can perhaps start here. https://docs.djangoproject.com/en/dev/howto/deployment/
First, find out the django version required by your client. Install that on a server (not a production one), setup apache and mod_wsgi. The zip files may go to a dir which can be included in the mod_wsgi configuration.
Find about the static files and setup apache or any other lightweight webserver to server it.
You may not be a developer, but have a try with the django book. It can give you a good idea how its structured.

Using Django's built in web server in a production environment

I'm going to setup a simple Django app running in a production environment on a Linux box. The app will have very little traffic - less that 100 page loads per day. Is it okay to use the builtin Django webserver for this or should I install Apache and mod_wsgi? If so, what are the reasons for this? Security perhaps?
UPDATE
OK it is clear I shouldn't be using the builtin server. Some of the alternatives to Apache look interesting. Is there one that is more popular/more frequently used with Django perhaps?
Is it okay to use the builtin Django webserver for this
No.
Should I install Apache and mod_wsgi?
Yes.
If so, what are the reasons for this? Security perhaps?
Partly.
More importantly, the little toy Django server is single-threaded and any hangup in your code hangs the server. This means that when two users click almost at the same time, user one's query must go all the way through Django before user two's query can even starts.
And this will have to include the insanely slow download speed to the desktop.
Apache (like all the alternatives, lighttpd or nginx) is multi-threaded. The slowest part of the transaction is the download from Apache to the desktop. You don't want Python code (and Django) handling this in a single-threaded manner. Even for just a few users.
Also, you don't what Django serving static media (i.e., CSS and JS library files.)
A single slow spot in your application won't effect the overall system throughput if Apache and mod_wsgi are in place. One request 's output page can be slowly downloading to a PC desktop in parallel with another user's output.
DO NOT USE THIS (the builtin Django webserver) SERVER IN A PRODUCTION SETTING. It has not gone through security audits or performance tests.
http://docs.djangoproject.com/en/dev/ref/django-admin/#runserver-port-or-address-port
But you don't have use Apache if you don't want to. You could directly use Spawning, Gunicorn etc.
Cherokee is also easy to setup.
Use nginx + gunicorn.
Nginx: five lines of configuration. Gunicorn: two lines of configuration. That's easy and efficient. For better control you can spawn the gunicorn process using supervisord.
Both gunicorn and supervisord are available to install with pip, and nginx is available in almost any distribution in the default package pool.
The built in Django server was not built for production. There are many reasons why, mainly security and efficiency.
The recommended way is to use mod_wsgi which is covered in the docs here

Django: Moving from XAMPP to Django questions

I've worked with XAMPP, WAMPP, MAMPP, etc and am starting to look at Django.
A majority of the work we do is very CMS orientated; although we've been told not to use third-party CMS' (mainly because of user's find them hard to use, and other issues), I've found that I can code a very simple CMS using Cake, CodeIgniter or one of the other PHP frameworks.
And yet, I'm getting increasingly frustrated with the amount of coding I need to do just to get something up and running, and I've been told that Django is a good Python framework to use. It also seems to get a lot of buzz from reddit.
I have some concerns and queries about moving from XAMPP to Django.
1) Security
Any web app should be coded defensively. Over the past few years we've seen a movement towards protecting against XSS, SQL injections, Cross site forgeries, session fixation, session hi-jacking, cookie hi-jacking; the amount of security one needs can be overwhelming.
What things does Django do to prevent/limit XSS, SQL injections, Javascript injections, and santizing input; one normally associates with securing PHP web apps? Is it something I need to worry about, or does Django do all this stuff out of the box.
2) What goes in the /www/ public folder?
In a manual I read it said not to put manage.py or the other .py stuff in the main webroot, so this means I put everything outside of the webroot; so what goes in there?
Do I put the /templates/ directory inside the webroot? How does the server know what to run?
3) Can I still use .htaccess on Django projects? I am familiar with Apache and often use it to do routing, or blocking off bad bots, but will using .htaccess still work?
4) Cronjobs
Do cronjobs still work with Python/Django projects?
5) Running Third party perl/other scripts
In PHP you can use other libraries such as the curl library, ffmpeg, ImageMagik as well as many others; can I still use these libraries with Python/Django?
6) Admin screen
Django gives you an out-of-the-box admin screen; is this only for development purposes or can it put live? I am concerned about any the security of the admin screen.
7) Integration with Discuss, Facebook, Twitter, OpenID, captcha, etc.
There are libraries in PHP that help integrate DisQuss, Facebook, Twitter; but is it relatively easy to do an integration with these and other third party apps?
8) E-commerce, SSL
Are there many e-commerce sites that use Django? I've seen a lot of CMS/Blog type software but not many e-commerce sites. By which I mean, shopping card, Protx/Paypal or Worldpay integration.
That's another thing; there are sandboxes for Protx, Paypal, Worldpay etc for PHP -- but are there any for Django?
9) Is it worth it?
Is it worth moving to Django from an XAMPP background? Will it really make things faster, or is that just marketing hype?
Thanks.
Security. The Django core team are very security-conscious, and have taken great care to make things like SQL injection impossible. The next version, 1.2, includes a whole new cross-site request forgery protection library. Obviously, you still need to be aware of these when developing your application, but Django does a lot to help you.
What goes under /www/public: Nothing. Django doesn't work via the normal Apache serving mechanism: it hooks into (preferably) mod_wsgi, which needs a single file which then tells it to run the rest of the code. The templates can go anywhere, and are pointed to by your Django settings file, but again aren't served directly by Apache.
.htaccess: You don't really need it, because of point 2: you're not serving things in a filesystem hierarchy. The best way to do it is to set up vhosts and manage things that way.
Cron jobs: Absolutely. Django is just Python, and you can easily run Python scripts via cron. Django allows you to set up custom command scripts which initialise the ORM and give you access to anything you would need.
Libraries: Again, because Django is Python, you get access to the huge amount of Python libraries that are out there. For curl, Python has urllib; for ImageMagick, it has PIL; and no doubt there are equivalents of ffmpeg too.
Admin: Again, security has been thought of from the beginning. Opinions differ as to whether you should use the admin only for your expert users, or customise it and allow access for all users; I've had a lot of success using it as the basis for my custom CMS interfaces.
Facebook, etc: Yes, there are libraries for all of these.
E-commerce: There is a whole e-commerce project, Satchmo, written in Django. Libraries exist to interface with all the payment providers.
Is it worth it? Only you can tell. My experience working alongside a range of developers who have moved from PHP is that they've enjoyed the experience and became much more productive.
On SQL Injections: Django uses an ORM, which takes care of SQL injection protection, and you will rarely write you own SQL. If you do, just follow the instructions on how to pass parameters to raw queries and prevent SQL Injections.
There is an entire chapter on the django book about security that should answer all your questions.
On what goes into /www/: anything that is not code? The concern is to not put the python code there.
On .htaccess: Yes, it should still work (for any non Django resources as Daniel points out).
On cronjobs: what do you mean?
On Libraries: Python - the language you will use with Django - is rich in libraries that probably provide the same functionality you are used to. This is a key point: you will need to learn Python well to benefit the most from Django.
On the admin interface: This is actually the thing that will probably help you the most, judging from your question. They are customizable (within some limits) and they really give the staff (it is not intended for public users, but for staff users) the basics of CRUD for your database models. It is a time saver. You might need to write your own templates for advanced functionality, but for most simple CRUD aimed at staff (which is usually the point of a CMS) it is very useful and easy to set up.
On integration: Check Pinax for a group of applications that provide extra functionality. There is a rich and diverse universe of integration solutions out there. It is not unusual to find questions here in SO about django + facebook and others.
On E-commerce: Check Satchmo out.
Is it worth it: Now, I have no experience with XAMPP. I know that I like Python better than both Perl and PHP (and Java, for that matter). I know that as a framework Django is simpler to use, faster to deploy than anything I used before.
My suggestion is the age old: go build a simple project and make up your own mind. You are the only one in position to decide if Django is the framework for you.
An older question on SO discusses some Django limitations. My answer to that might be helpful to you too.
I recently moved to developing any new projects in Django, coming from a PHP background. Here are my thoughts on your questions.
1) Security
Strings sent to templates is escaped by default, which takes care of most of that. Since you're using an ORM, SQL injection shouldn't be an issue unless you build raw queries for some reason.
2) What goes in the /www/ public folder?
Django doesn't use a file hierarchy for URLs like a typical PHP setup. The server knows what to run from your urls.py and settings.py pointer to the template folder.
3) Can I still use .htaccess on Django projects? I am familiar with Apache and often use it to do routing, or blocking off bad bots, but will using .htaccess still work?
As noted above, it works for static content just the same. For dynamic pages, you'd want to implement some other form of authentication or redirection for clients you want to block, as far as I know.
4) Cronjobs
There's no reason why you can't use cron for whatever, as you still have a normal Linux system.
5) Running Third party perl/other scripts
You'll want to use the Python versions of those libraries, of course. For instance
FFMpeg
PythonMagick
I replaced most of my need for Curl with the built-in urllib and urrlib2 libraries, but there is also PyCurl if you need it.
6) Admin screen
The Admin screen is intended to be used by your own admins, i.e. site staff. It may be possible to do so, but it's not supposed to be the scaffolding on which you build your public facing project.
7) Integration with Discuss, Facebook, Twitter, OpenID, captcha, etc.
There are a lot of people out there using Python and Django, and I haven't had any problem finding libraries. In my experience there is a bit less support for something than PHP, but what is there is often higher quality.
8) E-commerce, SSL
I haven't tried payment integration, so I can't say. Not sure about the other sites, but the Paypal Sandbox is run by Paypal, isn't it? I don't think it's related to what you're using on the server, so sure, you can access it like normal.
9) Is it worth it? Is it worth moving to Django from an XAMPP background? Will it really make things faster, or is that just marketing hype?
I moved to Django because Python is truly a more compelling language than PHP. Will it make things faster? I'm not sure what the advantages in that respect would be for Django vs.the PHP MVC frameworks. There are no magic bullets.
You do have to keep in mind that you're not just learning a new framework, but also a new language. There will be a bit of a learning curve if you've never used Python before. but I've found both Python and Django to be fairly easy to learn. The clean design of the language is fantastic and Django is veryt well designed, too. I do feel that it's boosting my productivity. I've found snippets for or articles about most everything I need to do in Django as I've been learning, so adapting has been pretty simple.