Re: [Fab-user] Fabric execution with Python calls instead of command-line

[Jeff Forcier]

Hi Carles,

On Tue, Nov 23, 2010 at 4:23 PM, Carles Barrobés i Meix
<address@hidden> wrote:

> - Can I rely on using functions in fabric.main?

At this time, no, it's not part of the published API. Basically, if
it's not in the API section of the docs, it's not public API material,
and we reserve the right to change it in otherwise
backwards-compatible releases. Doesn't mean we *will*, but this is the
usual caveat emptor with all APIs :)

> - Are there plans to refactor fabric.main so that it is more usable in the
> way I suggest, and eventually become a published API?

Yes-- in future releases we'll be refactoring more of that stuff out
into things such as e.g. execute(task_obj, host_list) and having
fabric.main eat that dogfood. Ideally, fabric/main.py will end up
being a very light wrapper that just handles CLI options and fabfile
discovery and that's it. Not sure when we'll get there but it is
definitely planned.

> - Would you be open to contributions in that direction?

We're always open to ideas and patches, though this particular sort of
thing ("core" features) is more sticky than other parts of the
codebase and changes to it will probably be met with more skepticism
or at least need more time to be mulled over :) Just so you're aware.

Finally -- I just added a note on how to use Fabric as a library, to
the docs, the other day:

    http://docs.fabfile.org/usage/library.html

By following that, you don't actually need to "parse" a fabfile at
all. Simply importing it as a Python module and calling task functions
may suffice, depending on how much "main-like" stuff (env.hosts,
host/role decorators, etc) the fabfile relies upon to work correctly.

Most folks tend to use Fabric in an either-or fashion -- writing
fabfiles for use with 'fab', OR using Fabric's API solely as a library
and disregarding 'fab' entirely -- so if you truly want to do both you
may be the first person to have that particular need.

It should be possible, but might require some refactoring of your
fabfile into something more library-esque, and may also require a bit
of tweaking of host lists and such on the non-fabfile side (again as
outlined briefly in that library-use doc).

Hope that all makes sense, blasting it out as I leave work for the day :)

Best,
Jeff

-- 
Jeff Forcier
Unix sysadmin; Python/Ruby engineer
http://bitprophet.org