Automating virtualenv and Django development server startup with fabric?

Question

Possible Duplicate:
Activate a virtualenv via fabric as deploy user

I've been advised to try and use fabric for deploying Django to a production server, and automating tasks by using python instead of bash.

I wanted to start easily and just automate the activation of my virtualenv, and start the Django development server in it.

I've created a file named fabfile.py:

from fabric.api import local

def activate_env():
    local("source /.../expofit_env/bin/activate")

def run_local_server():
    local("/.../server/manage.py runserver")

def start():
    activate_env()
    run_local_server()

However, when I run

fab start

i get the following message:

[localhost] local: source /.../expofit_env/bin/activate
/bin/sh: 1: source: not found

Fatal error: local() encountered an error (return code 127) while executin
'source /.../expofit_env/bin/activate'

What am I doing wrong?

Update

Based on Burhan Khalid's proposal, i tried the following:

....
def activate_env():
    local("/bin/bash /.../expofit_env/bin/activate")
....

Running just

fab activate_env

results:

[localhost] local: /bin/bash /.../expofit_env/bin/activate

Done.

However after execution, virtualenv isn't activated. For the following code:

def start_env(): 
    with prefix('/bin/bash /.../expofit_env/bin/activate'): 
        local("yolk -l")

I still get an error, as if virtualenv wasn't activated.

alan@linux ~/Desktop/expofit $ fab start_env
[localhost] local: yolk -l
/bin/sh: 1: yolk: not found

When i manually activate virtualenv, yolk workd fine:

alan@linux ~/.../expofit_env $ source bin/activate
(expofit_env)alan@linux ~/.../expofit_env $ yolk -l

DateUtils       - 0.5.2        - active 
Django          - 1.4.1        - active 
Python          - 2.7.3rc2     - active development (/usr/lib/python2.7/lib-dynload)
....

Update

Tried a new approach from this question.

from __future__ import with_statement
from fabric.api import *
from contextlib import contextmanager as _contextmanager

env.activate = 'source /.../expofit_env/bin/activate'

@_contextmanager
def virtualenv():
    with prefix(env.activate):
        yield

def deploy():
    with virtualenv():
        local('yolk -l')

Gives the same error:

[localhost] local: yolk -l
/bin/sh: 1: source: not found

Fatal error: local() encountered an error (return code 127) while executing 'yolk -l'

Aborting.

Even dough the first command passes without errors:

alan@linux ~/.../expofit_env/bin $ fab virtualenv

[servername] Executing task 'virtualenv'

Done.

Update

It is possible to run the local with a custom shell.

from fabric.api import local

def start_env():
        local('source env/bin/activate',shell='/bin/bash')

However, that didn't activate the virtualenv as if it was done manually.

remove `source`, it should be `/bin/bash /path/to/bin/activate` — Burhan Khalid, Oct 03 '12 at 11:44
@BurhanKhalid It runs without errors, however it doesn't activate the virtualenv. — TheMeaningfulEngineer, Oct 04 '12 at 06:22
The code is: `def start_env():` `with prefix('/bin/bash /.../expofit_env/bin/activate'):` I run it with `fab start_env` `local("yolk -l")` — TheMeaningfulEngineer, Oct 04 '12 at 07:02
You keep using `source`, which is why you keep getting the same error. — Burhan Khalid, Oct 04 '12 at 07:13
@BurhanKhalid I updated the question. Check the section related with the first update (the one updated based on your recommendation). No `source` there. The second update is a solution based on the second answer. — TheMeaningfulEngineer, Oct 04 '12 at 07:34
@Alan -- did you ever get an answer to this question? the code in the "duplicate" question generates the same error you're describing (basically, that fabric is trying to invoke `source` using `sh` as a shell -- despite my `env.shell` being set correctly). — simon, Jul 13 '13 at 04:38
@simon what's your `env.shell`? `/bin/bash -l -c` should do it. — Dave, Aug 23 '13 at 08:19
@simon Found something new. But not the solution yet. Updating question. — TheMeaningfulEngineer, Sep 16 '13 at 14:01
@simon Tried running `source env/bin/activate` as a shell script also doesnt activate virtualenv. — TheMeaningfulEngineer, Sep 16 '13 at 14:08
@simon Found [this answer](http://stackoverflow.com/a/6944649/1214214) works for a bash script. Now we have to figure out how to do the `--rcfile` through fabric. — TheMeaningfulEngineer, Sep 16 '13 at 14:20
@Alan I had exactly the same problem with you. I solved problem as following. `#!/bin/bash` `def workon(): local("/bin/bash --rcfile /home/{USERNAME}/.virtualenvs/{VIRTUALENV NAME}/bin/activate")` — Chemical Programmer, Oct 09 '14 at 17:00

score 3 · Answer 1 · answered Oct 04 '12 at 00:13

3

To use enable a virtualenv from the fab file you need to run your commands as follow:

def task():

    # do some things outside the env if needed 

    with prefix('source bin/activate'):
        # do some stuff inside the env
        pip install django-audiofield

All the commands within the with bloc will be executed inside the virtualenv

answered Oct 04 '12 at 00:13

Jeff

233
2
7

3

It didn't work. Resulted the same "/bin/sh: 1: source: not found " error. – TheMeaningfulEngineer Oct 04 '12 at 06:19

score 2 · Answer 2 · answered Oct 03 '12 at 11:20

2

By default you are using the sh shell, and the source command is a bashism (that is, something that only works in bash).

To activate your environment, you need to execute it with bash directly. /bin/bash /path/to/bin/activate.

answered Oct 03 '12 at 11:20

Burhan Khalid

169,990
18
245
284

Updated the question based on your proposal. – TheMeaningfulEngineer Oct 03 '12 at 11:38
@Alan is correct -- while this answer is relevant, it does not solve the problem – simon Jul 13 '13 at 04:42

Automating virtualenv and Django development server startup with fabric?

2 Answers2