How do I create a new file on a remote host in fabric (python deployment tool)?

Question

I'd like to create a file with the name passenger_wsgi.py on a remote host. I'd like to use the following string to create the file's content:

'''
import sys, os

sys.path.insert(0, "/ruby/%s/www/%s/django-projects")
sys.path.insert(0, "/ruby/%s/www/%s/django-projects/project")

import django.core.handlers.wsgi
os.environ['DJANGO_SETTINGS_MODULE'] = 'project.settings'
application = django.core.handlers.wsgi.WSGIHandler()
''' % (user,host,user,host)

The user and host variables would be parameters of the fabric function.

I'm a total newbie to any sort of file manipulation in python, but also I'm not really sure what the procedure should be in fabric. Should I be creating the file locally and then uploading it with fabric's put command (and removing the local version afterwards)? Should I be creating the file on the remote host with an appropriate bash command (using fabric's run)? If so, then how is it best to deal with all the " and ' in the string - will fabric escape it? Or should I be tackling this in some different manner?

Answer 1

You could use append() or upload_template() functions from fabric.contrib.files

Answer 2

Use StringIO with put:

text = '''
import sys, os

sys.path.insert(0, "/ruby/%s/www/%s/django-projects")
sys.path.insert(0, "/ruby/%s/www/%s/django-projects/project")

import django.core.handlers.wsgi
os.environ['DJANGO_SETTINGS_MODULE'] = 'project.settings'
application = django.core.handlers.wsgi.WSGIHandler()
''' % (user, host, user, host)

import StringIO
put(StringIO.StringIO(text), "remote-path")

Answer 3

What I do is have the file locally as something like "app.wsgi.template".

I then use tokens in the file, like:

import sys, os

sys.path.insert(0, "/ruby/$HOST$/www/$HOST$/django-projects")
sys.path.insert(0, "/ruby/$HOST$/www/$HOST$/django-projects/project")

import django.core.handlers.wsgi
os.environ['DJANGO_SETTINGS_MODULE'] = 'project.settings'
application = django.core.handlers.wsgi.WSGIHandler()

I use fabric to "put" the file over to the remote host, then use "sed" (or equivalent functions in Python) to replace the "$HOST$" and "$USER$" tokens with the values I want.

run("sed -i backup -e 's/$USER$/%s' -e 's/$HOST$/%s' app.wsgi.template" % (user, host))
run("mv app.wsgi.template app.wsgi")

Answer 4

StringIO with put works with a little bit of editing. Try this:

put(StringIO.StringIO(
'''
import sys, os

sys.path.insert(0, "/ruby/%s/www/%s/django-projects")
sys.path.insert(0, "/ruby/%s/www/%s/django-projects/project")

import django.core.handlers.wsgi
os.environ['DJANGO_SETTINGS_MODULE'] = 'project.settings'
application = django.core.handlers.wsgi.WSGIHandler()
''' % (user,host,user,host)), "remote-path")

if you have an issue with permissions, try this:

put(StringIO.StringIO(
'''
import sys, os

sys.path.insert(0, "/ruby/%s/www/%s/django-projects")
sys.path.insert(0, "/ruby/%s/www/%s/django-projects/project")

import django.core.handlers.wsgi
os.environ['DJANGO_SETTINGS_MODULE'] = 'project.settings'
application = django.core.handlers.wsgi.WSGIHandler()
''' % (user,host,user,host)), "remote-path", use_sudo=True)