Fwd: [Fab-user] Virtualenv Use Case

[Steve Steiner]

On May 2, 2009, at 11:53 AM, Jeff Forcier wrote:

> On Sat, May 2, 2009 at 11:27 AM, s s <address@hidden>  
> wrote:
>
> > Yes.  Context managers are 2.5+ but that's fine with me.  You only  
> > need 2.5
> > on the deployer i.e. your development machine so I don't think this  
> > should
> > be too much of a problem.
>
> Fabric is officially 2.5+ only [1], so yea. Context managers are
> totally a good thing and I want to use more of them :)
>
> [1] http://docs.fabfile.org/compatibility.html#python-version

Cool.

> > Only thing with that is you lose the ability to grab error/status  
> > info from
> > each command.  One of my other use-cases involves finding out  
> > whether a
> > command exists on the target machine (wget, for example) and  
> > installing it
> > if it doesn't.
>
> This is another reason to prefer the context manager approach, as it
> combines the best of both worlds: your commands still get run with the
> appropriate shell environment, but you also still have discrete
> run/sudo invocations, complete with their own return codes/failure
> handling/etc.
>
> One edge case this doesn't cover is when one of your shell commands
> modifies the shell environment itself, but I'm not sure if that
> happens often enough to merit doing a lot of switching things around
> or adding lots of complexity, though.

Uh, the first thing switching to a virtual environment does is  
mutilate the environment so that the virtenv becomes the "context" for  
subsequent commands or do you mean something else?

S