Setting Shell_Env before running prefix

[wbashir]

I would like to run and set my shell_env before the execution of the prefix. It looks like my shell env is never set in the example below:

with shell_env(ENV1="TEST"):
    with prefix(". myapp"):
          run("echo $ENV2")

I expected my shell_env to be set but my prefix runs first. I know this because the prefix commands uses the environment variables and will prompt for them if not set?

[wbashir]

I have to run another prefix and export my environment variables directly as a workaround. Any help ?

[cmattoon]

This code generates the following final command:

from fabric.api import *

def test1():
    with shell_env(ENV1="IT WORKS",ENV2="TEST2"):
        with prefix("echo $ENV1"):
            run("echo $ENV2")

/bin/bash -l -c "echo \$ENV1 && export ENV2=\"TEST2\" ENV1=\"IT WORKS\" && echo \$ENV2"

Changing this in fabric/operations.py obtains the desired output for this bug, but I'm not sure how this will affect other use cases.

         wrapped_command = _shell_wrap(
             _prefix_env_vars(_prefix_commands(command, 'remote')),
             shell_escape,
             shell,
             _sudo_prefix(user, group) if sudo else None
 )

    wrapped_command = _shell_wrap(
             _prefix_commands(_prefix_env_vars(command), 'remote'),
             shell_escape,
             shell,
             _sudo_prefix(user, group) if sudo else None
    )

/bin/bash -l -c "export ENV2=\"TEST2\" ENV1=\"IT WORKS\" && echo \$ENV1 && echo \$ENV2"

This passed the existing tests, minus the two below that failed in master as well.

======================================================================
ERROR: abort() should print 'Fatal error' plus exception value
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/usr/lib/python2.7/dist-packages/nose/case.py", line 197, in runTest
    self.test(*self.arg)
  File "/home/tyler/git/fabric/tests/mock_streams.py", line 74, in inner_wrapper
    ret = func(*args, **kwargs)
  File "/usr/local/lib/python2.7/dist-packages/fudge-1.0.3-py2.7.egg/fudge/patcher.py", line 148, in method_call
    patched_obj.restore()
  File "/usr/local/lib/python2.7/dist-packages/fudge-1.0.3-py2.7.egg/fudge/patcher.py", line 320, in restore
    delattr(self.orig_object, self.attr_name)
AttributeError: aborts
======================================================================
ERROR: warn() should print 'Warning' plus given text
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/usr/lib/python2.7/dist-packages/nose/case.py", line 197, in runTest
    self.test(*self.arg)
  File "/home/tyler/git/fabric/tests/mock_streams.py", line 74, in inner_wrapper
    ret = func(*args, **kwargs)
  File "/usr/local/lib/python2.7/dist-packages/fudge-1.0.3-py2.7.egg/fudge/patcher.py", line 148, in method_call
    patched_obj.restore()
  File "/usr/local/lib/python2.7/dist-packages/fudge-1.0.3-py2.7.egg/fudge/patcher.py", line 320, in restore
    delattr(self.orig_object, self.attr_name)
AttributeError: warnings
----------------------------------------------------------------------
Ran 392 tests in 122.098s
FAILED (errors=2)

[wbashir]

@cmattoon Thanks for investigating, I have been looking for a cleaner solution. @bitprophet thoughts on this ?

[cmattoon]

I can also add a kwarg (ala #1208) if needed.

[bitprophet]

Yea offhand I don't see how this is anything other than an oversight in the implementation of shell_env. And since it's just sugar, it shouldn't seriously break things for anybody in a way they cannot fix themselves.

[bitprophet]

Closing to roll into #1241, thanks @cmattoon!