5 minute read

Just notes on what I’m up to in trying to get django to work for my Computer Science 462 class. I find this helpful for remembering where I left off and commands etc. But you will probably find it very boring unless you try and do the same.

using tutorial at http://docs.djangoproject.com/en/dev/intro/tutorial01/

==========================

Found I needed root priviledges, so I allowed the default users, ‘ubuntu’ root priledges by calling

so I logged into bash as root by just typing

|sudo bash

then editing the /etc/sudoers file by typing

|visudo

and adding changing the line from

root ALL=(ALL) ALL

to

ubuntu,root ALL=(ALL) ALL

===========================

I edited the settings file settings.py, and configured stuff for sqlite3, like the tutorial suggested.

then, as it suggested, ran

python manage.py syncdb

which created the database file where I wanted it in /var/django/db/mikeServ.db

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tried to view the schemas by typing

|.schema

with no luck. googled how to view schemas in sqlite.

Googled what the matter might have been, found I needed pysqlite2, so ran

|aptitude search pysqlite2

found it, and ran

|apt-get install python-pysqlite2

but still can’t find anywhere how to use it really, nor what comes with that package

bah. I’ll just assume it worked for now, even thought I can’t check it. we shall see.

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I want to use django for a class project which really doesn’t require a local database, just using ajax and templates, so I skipped over the rest of the first page of teh tutorial having to do with creating objects/tables, but it seeemd good.

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was interested in the admin pages to work, so I followed the instructions on teh next page:

added django.contrib.admin to INSTALLED_APPS in settings.py,

and ran

|python manage.py syncdb

then edited urls.py as indicated.

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Tried to run the /admin/ pages, but no go. I think I might need to restart the webserver:

|/etc/init.d/apache2 restart

When I visited my site (http://50.16.162.246/admin/) the next time, made some progress: got an error message! somethign about indentatino error in ursl.py, so I’ll go fix taht. (Found the compy was right: forgot to remove preceding white-space when uncommenting).

Now though, I’m getting a 500 error with no real helpful input. Hmm. progress? probably. I bet the error is coming from not reaaally having the database schemas, though I ran syncdb ‘n all. I should verify those exist for reals.

I foudn the problem was I don’t have django stuff on my path, as explained in http://martinjansen.com/2008/10/20/django-settings-files-for-development-and-production/. I just need to add my settings.py file to the PATH, and some DJANGO_SETTINGS.

Trouble with that, some help also on http://ubuntuforums.org/showthread.php?t=125735

Found that didn’t permanently solve anything. (This forum page has a good explanation of different config files like .bashrc and .bashprofile and stuff: http://ubuntuforums.org/showthread.php?t=125735).

Eventually, found an easy way to add to the PYTHONPATH is just to add a file named whatever.pth to something that already is on a the pythonpath (like /usr/local/lib/python2.6/dist-packages) and in that file write nothing but the path to whatever I want to add to the python path.

Still the DJANGO_SETTINGS_MODULE isn’t found.

Then I realized I had edited the wrong .bashrc file. I edited /.bashrc, when really I should ahve edited ~/.bashrc. bah!

So edited taht file instead, restarted teh command-prompt shell, and voila!

I could verify that PYTHONPATH was set by typing in

|$PYTHONPATH

into the shell and it would print it out

However, I’m still getting a 500 error on teh admin pages.

Added a symbolic link to the admin media stuff like suggested on http://docs.djangoproject.com/en/dev/howto/deployment/modwsgi/, but that didn’t resolve it.

Now I’m looking at http://code.djangoproject.com/wiki/django_apache_and_mod_wsgi

Ok, more of the same. But I’m onto something now.

I thought I really needed to see some better error logs. So I searched for where are the apache error logs, and found it’s at:

/var/log/apache2/error.log, right next to the access.log (I didn’t know they were seperate). I then noticed what the error seems to be:

[Sat Jan 29 16:25:55 2011] [error] [client 67.166.99.183] OperationalError: attempt to write a readonly database

meaning the sqlite file that its trying to write to is set to be read-only. Which kinda makes sense. So I’m gonna check what the files permissions are, and change them to amke them write-whatever-you-want. (Did that by going to the file, which I placed in /var/django/db/mikeServ.db and did the command chmod 777 mikeServ.db)

and BOOM BABY! Admin console!

Except I didn’t create the symbolic link to the media files right.

And then I noticed it stillw asn’t redirecting quite right. So I needed to edit the apache config file some more. Basically, I needed to make apache get the media files from where they’re at on the server. So I added these lines to my /etc/apache2/sites-available/default file:

Alias /media/ /usr/lib/pymodules/python2.6/django/contrib/admin/media/

Order deny,allow

Options Indexes

Options FollowSymLinks

Allow from all

==================================

ok so now I’m trying to get some pages to work,

I ran

|python manage.py startapp view

|” ” ” list

|” ” ” home

to create 3 ‘apps’ I guess that will host my files

and added those 3 things to my list of installed apps

and another issue is I’m not sure if django-admin.py is on my filepath. …actually immediately remembered: it is, just under a different name, it’s under django-admin (no ‘.py’)

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so I finished those views.py files, as follows:

<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<

Create your views here.

from django.http import HttpResponse

from django.template import Context, loader, Template

import urllib2

import json

def popular(req):

t = loader.get_template(‘popular.tmpl’)

return HttpResponse(t.render({}))

def recent(req):

t = loader.get_template(‘recent.tmpl’)

response=urllib2.urlopen(‘http://imaj-app.lddi.org:8010/list/recent’)

dictResponse=json.loads(response.read())

c = Context({‘imagelist’: dictResponse[‘images’],’nextsubmitdate’:dictResponse[‘nextsubmitdate’],’nextratesort’:dictResponse[‘nextratesort’]})

return HttpResponse(t.render(c))

>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>

and then the template:

<<<<<<<<<<<<<<<<<<<<<<<,

.listitem {

margin-bottom: 2em;

}

.listitem a {

float:left;

margin-right: 2em;

}

Recent Images

{% for image in imagelist %}

{% endfor %}

{% if nextsubmitdate %}

More Images …

{% endif %}

>>>>>>>>>>>>>>>>>>>>

the ta gave the template to us originally in some ‘cheetah’ python template language, but converting it to django’s template language was easy: the semantics (the way it works) are just the same, just silly difference in syntax.

and voila! I have a page which renders! bwahahaha!

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I noticed the page was missing headers, css stuff, etc.

After inspecting the templates, I realized they had no declaration of etc, or importing of css files. Reason: I wasn’t using the main template at all!

Apparently Cheetah works differently from django’s template. In Cheetah the parent template imports the others by just inserting $main somewhere in teh html. IN django, you need a tag in the parent saying

{% block WHATEVER %}{%endblock%} and in the child template, you need to start with {

%extends ‘WHATEVERYOUCALLEDTHEPARENT.tmpl’%}

and then

{%block WHATEVER%} {%endblock%} (note that the names must match)

And then when it loads the child template, it’ll look for teh parent, load it, and insert the child template where indicated.

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About that css stuff. Sure enough, it wasn’t finding the css.

I read somewhere about how you can serve static files simply using apache. That makes sense, but I think somehow my django config was interfering with the usual serving of static files from my directory of /var/www.

So, I poked around and noticed that I could just add

(r’^site_media/(?P.*)$’, ‘django.views.static.serve’,{‘document_root’: ‘./site_media’,’show_indexes’: True}),

to my list of urlpatterns in urls.py. But it wasn’t working.

After a bit, i noticed the reason: ‘./site_media’ was meant to point to where the static files folder was located on the hard drive. I suppose it’s meant to be a relative uri, but it wasn’t working. Switched it to a absolute uri and it worked.

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Starting making another page which was basically identical to my first one

(which just sends out a request and then parses it into a json object and displays it) and got a goofy error saying something about how the dict module had no function named ‘push’. Really random. I saw it before htough. And I had the advantage of this page being basically the exact same as the previous one. So I compared them: identical. Then I remembered: sometimes you need to restart apache for the python to get reloaded. So restarted apache and it worked.

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wanted to be able to log stuff on my server.

SO, I followed the instructions on http://djangosnippets.org/snippets/1731/,

and added ‘site_logging’ to my list of installed apps, and added the site_logging.py file in the root of my django/mikeServ directory. Then called logging as instructed (even though I would have thought I should have been calling ‘site_logging’, but just ‘logging’ did it.)

Viewed the error log using

|tail -f /var/log/apache2/error.log

BOOM BABAY!

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