Django Advice

• Vagrant
  • Why Vagrant?
  • Using Fabric to Stay Fast and Automate Everything
• Wrangling Databases with South
  • Useful Fabric Tasks
• Watching for Changes
  • Using the Werkzeug Debugger with Gunicorn
  • Pulling Uploads
  • Preventing Accidents
• Working with Third-Party Apps
  • Installing Apps from Repositories
  • Mirroring Repositories
  • Using BCVI to Edit Files
• Improving the Admin Interface
  • Enter Grappelli
  • An Ugly Hack to Show Usable Foreign Key Fields
• Using Django-Annoying
  • The render_to Decorator
  • The ajax_request Decorator
• Templating Tricks
  • Null Checks and Fallbacks
  • Manipulating Query Strings
  • Satisfying Your Designer with Typogrify
• The Flat Page Trainwreck
• Editing with Vim
  • Vim for Django
  • Filetype Mappings
  • Python Sanity Checking
  • Javascript Sanity Checking and Folding
  • Django Autocommands
• Conclusion

def cmd(cmd=""):
    '''Run a command in the site directory.  Usable from other commands or the CLI.'''
    require('site_path')

    if not cmd:
        sys.stdout.write(_cyan("Command to run: "))
        cmd = raw_input().strip()

    if cmd:
        with cd(env.site_path):
            run(cmd)

def sdo(cmd=""):
    '''Sudo a command in the site directory.  Usable from other commands or the CLI.'''
    require('site_path')

    if not cmd:
        sys.stdout.write(_cyan("Command to run: sudo "))
        cmd = raw_input().strip()

    if cmd:
        with cd(env.site_path):
            sudo(cmd)

def vcmd(cmd=""):
    '''Run a virtualenv-based command in the site directory.  Usable from other commands or the CLI.'''
    require('site_path')
    require('venv_path')

    if not cmd:
        sys.stdout.write(_cyan("Command to run: %s/bin/" % env.venv_path.rstrip('/')))
        cmd = raw_input().strip()

    if cmd:
        with cd(env.site_path):
            run(env.venv_path.rstrip('/') + '/bin/' + cmd)

def vsdo(cmd=""):
    '''Sudo a virtualenv-based command in the site directory.  Usable from other commands or the CLI.'''
    require('site_path')
    require('venv_path')

    if not cmd:
        sys.stdout.write(_cyan("Command to run: sudo %s/bin/" % env.venv_path.rstrip('/')))
        cmd = raw_input().strip()

    if cmd:
        with cd(env.site_path):
            sudo(env.venv_path.rstrip('/') + '/bin/' + cmd)

def syncdb():
    '''Run syncdb.'''
    require('site_path')
    require('venv_path')

    with cd(env.site_path):
        run(_python('manage.py syncdb --noinput'))

def collectstatic():
    '''Collect static media.'''
    require('site_path')
    require('venv_path')

    with cd(env.site_path):
        sudo(_python('manage.py collectstatic --noinput'))

def rebuild_index():
    '''Rebuild the search index.'''
    require('site_path')
    require('venv_path')
    require('process_owner')

    with cd(env.site_path):
        sudo(_python('manage.py rebuild_index'))
        sudo('chown -R %s .xapian' % env.process_owner)

def update_index():
    '''Update the search index.'''
    require('site_path')
    require('venv_path')
    require('process_owner')

    with cd(env.site_path):
        sudo(_python('manage.py update_index'))
        sudo('chown -R %s .xapian' % env.process_owner)

def check():
    '''Check that the home page of the site returns an HTTP 200.'''
    require('site_url')

    print('Checking site status...')

    if not '200 OK' in local('curl --silent -I "%s"' % env.site_url, capture=True):
        _sad()
    else:
        _happy()

from fabric.colors import red, green

def _happy():
    print(green('\nLooks good from here!\n'))

def _sad():
    print(red(r'''
          ___           ___
         /  /\         /__/\
        /  /::\        \  \:\
       /  /:/\:\        \__\:\
      /  /:/  \:\   ___ /  /::\
     /__/:/ \__\:\ /__/\  /:/\:\
     \  \:\ /  /:/ \  \:\/:/__\/
      \  \:\  /:/   \  \::/
       \  \:\/:/     \  \:\
        \  \::/       \  \:\
         \__\/         \__\/
          ___           ___           ___           ___
         /__/\         /  /\         /  /\         /  /\     ___
         \  \:\       /  /::\       /  /:/_       /  /:/_   /__/\
          \  \:\     /  /:/\:\     /  /:/ /\     /  /:/ /\  \  \:\
      _____\__\:\   /  /:/  \:\   /  /:/ /:/_   /  /:/ /::\  \  \:\
     /__/::::::::\ /__/:/ \__\:\ /__/:/ /:/ /\ /__/:/ /:/\:\  \  \:\
     \  \:\~~\~~\/ \  \:\ /  /:/ \  \:\/:/ /:/ \  \:\/:/~/:/   \  \:\
      \  \:\  ~~~   \  \:\  /:/   \  \::/ /:/   \  \::/ /:/     \__\/
       \  \:\        \  \:\/:/     \  \:\/:/     \__\/ /:/          __
        \  \:\        \  \::/       \  \::/        /__/:/          /__/\
         \__\/         \__\/         \__\/         \__\/           \__\/

         Something seems to have gone wrong!
         You should probably take a look at that.
    '''))

def KILL_IT_WITH_FIRE(app):
    require('site_path')
    require('venv_path')

    with cd(env.site_path):
        # Generate and download the reset SQL.
        sudo(_python('manage.py sqlreset %s > reset.orig.sql' % app))
        get('reset.orig.sql')

        with open('reset.sql', 'w') as f:
            with open('reset.orig.sql') as orig:
                # Step through the first chunk of the file (the "drop" part).
                line = orig.readline()
                while not line.startswith('CREATE'):
                    if 'CONSTRAINT' in line:
                        # Don't write out CONSTRAINT lines.
                        # They're a problem when you change db_colum names.
                        pass
                    elif 'DROP TABLE' in line:
                        # Cascade drops.
                        # Hence with "with fire" part of this task's name.
                        line = line[:-2] + ' CASCADE;\n'
                        f.write(line)
                    else:
                        # Write other lines through untoched.
                        f.write(line)
                    line = orig.readline()

                # Write out the rest of the file untouched.
                f.write(line)
                f.write(orig.read())

    # Upload the processed SQL file.
    put('reset.sql', os.path.join(env.site_path, 'reset.ready.sql'), use_sudo=True)

    with cd(env.site_path):
        # Use the SQL to reset the app, and fake a migration.
        run(_python('manage.py dbshell < reset.ready.sql'))
        sudo(_python('manage.py migrate --fake --delete-ghost-migrations ' + app))

def retag():
    '''Check which revision the site is at and update the local tag.

    Useful if someone else has deployed (which makes your production/staging local
    tag incorrect.
    '''
    require('site_path', provided_by=['prod', 'stag'])
    require('env_name', provided_by=['prod', 'stag'])

    with cd(env.site_path):
        current = run('hg id --rev . --quiet').strip(' \n+')

    local('hg tag --local --force %s --rev %s' % (env.env_name, current))

def tailgun(follow=''):
    """Tail the Gunicorn log file."""
    require('site_path')

    with cd(env.site_path):
        if follow:
            run('tail -f .gunicorn.log')
        else:
            run('tail .gunicorn.log')

def migrate(args=''):
    '''Run any needed migrations.'''
    require('site_path')
    require('venv_path')

    with cd(env.site_path):
        sudo(_python('manage.py migrate ' + args))

def migrate_fake(args=''):
    '''Run any needed migrations with --fake.'''
    require('site_path')
    require('venv_path')

    with cd(env.site_path):
        sudo(_python('manage.py migrate --fake ' + args))

def migrate_reset(args=''):
    '''Run any needed migrations with --fake.  No, seriously.'''
    require('site_path')
    require('venv_path')

    with cd(env.site_path):
        sudo(_python('manage.py migrate --fake --delete-ghost-migrations ' + args))

import os
import sys
import time
import signal
import threading
import atexit
import Queue

_interval = 1.0
_times = {}
_files = []

_running = False
_queue = Queue.Queue()
_lock = threading.Lock()

def _restart(path):
    _queue.put(True)
    prefix = 'monitor (pid=%d):' % os.getpid()
    print >> sys.stderr, '%s Change detected to \'%s\'.' % (prefix, path)
    print >> sys.stderr, '%s Triggering process restart.' % prefix
    os.kill(os.getpid(), signal.SIGINT)

def _modified(path):
    try:
        # If path doesn't denote a file and were previously
        # tracking it, then it has been removed or the file type
        # has changed so force a restart. If not previously
        # tracking the file then we can ignore it as probably
        # pseudo reference such as when file extracted from a
        # collection of modules contained in a zip file.

        if not os.path.isfile(path):
            return path in _times

        # Check for when file last modified.

        mtime = os.stat(path).st_mtime
        if path not in _times:
            _times[path] = mtime

        # Force restart when modification time has changed, even
        # if time now older, as that could indicate older file
        # has been restored.

        if mtime != _times[path]:
            return True
    except:
        # If any exception occured, likely that file has been
        # been removed just before stat(), so force a restart.

        return True

    return False

def _monitor():
    while 1:
        # Check modification times on all files in sys.modules.

        for module in sys