Nginx-Django Webfaction

Struggling with django trying to keep memory usage low in Webfaction, I tried it all

- DEBUG = False
- Caching entire the site
- Serving the static media with apache

basically all the tips I could find in webfaction forum,  till I read some people were recommending to install nginx and it will make your life easier in regards to memory. So I g00gled for anyone having this kind of setup in webfaction and this great article came up. Now all memory problems are solved.

1) First we need to create a new app in the Webfaction control panel I’m naming this for reference wf-app you can name it anything you like. Choose from the drop down menu “new app listening on port” this will give you a custom port which you will use later.

2) We need to create directories in our webapp folder and install Django and Flup (needed for the FCGI support later) so go ahead and ssh into your account and do the following.

3) Now we need to download and untar the latest stable versions of Nginx, Nginx_UploadProgress_Module and PCRE (for the embeded perl in Nginx). Updated added Open SSL.

4) Now lets configure, make and install Nginx
Without SSL

With SSL

let’s say all went well and we have no errors.

At this point we should have a working install of Nginx and Django.

Now we have some issues to worry about

• What happens if the Webfaction support team ever need to reboot the server?
• What happens if our Django App crashes?

We could solve this by adding a cron job to restart our stack every few minutes but because Nginx doesn’t spawn our FCGI Django process it gets quite complex, and we have no easy way to monitor the status.

The solution as suggested here is to use supervisor to control our server processes and then make sure that we have a cron job to check and restart supervisor.

1) Now go back to webfaction control panel and create a new app listening on port to reserve a port for Supervisor to run on, and make a note of the port number for later.

2) First we need to create a start script for Django so that supervisor can monitor it, use your favorite editor to create a file called runserver.py in your django project directory

with the following content:

Make it executable

3) We also need to change our django settings.py file and change the ROOT_URLCONF to:

Because supervisor can only interact with non daemonized processes we need to make a minor change to our nginx.conf file and add the following line right at the begining:

4) Time to install supervisor

5) Then create a file called supervisord.conf in your home directory with the following content replace port_number with the number you’ve got when you created the supervisor app. Make sure to replace the values that apply to your environment.

Assuming that all values have been replaced properly we could now start supervisor – however we would still suffer from the problem of supervisor not being started on a reboot. Let’s fix that – create a file called start_supervisor.sh in your home directory with the following content:

We’ll use this script to start and stop supervisor so we need to make it executable.

Now we need to add it to a cron job to make sure that it runs every few minutes (the script checks that supervisor is running so won’t start multiple instances of it) this will allow us to be back up and running a few minutes after the server comes back up.

Assuming you know the basics of VIM add the following, this will run the script every 10 min.

You should now be running on supervisor and your site should be up.
If you’d like to be able to see that status of your processes then mount the supervisor app we created at the start on a subdomain such as status.mydomain.com and then browse to that url (you’ll need to enter the user and password that you put into the supervisor.conf file)

Supervisor Screenshot

supervisor

Here is how my nginx.conf looks like, and how to add multiple sites.

Thanks Richard Cooper for this tutorial, great work!