How to discover current role in Python Fabric

Question

This is a very Fabric specific question, but more experienced python hackers might be able to answer this, even if they don\'t know Fabric.

I am trying to specify differ

Answer 1

Update: Just checked the source code and it seems that this was already available as early as 1.4.2!

update 2: This seems not to work when using the @roles decorator (in 1.5.3)! It only works when specifying the roles using the -R command line flag.

For fabric 1.5.3 the current roles are directly available in `fabric.api.env.roles'. For example:

import fabric.api as fab

fab.env.roledefs['staging'] = ['bbs-evolution.ipsw.dt.ept.lu']
fab.env.roledefs['prod'] = ['bbs-arbiter.ipsw.dt.ept.lu']


@fab.task
def testrole():
    print fab.env.roles

Test output on the console:

› fab -R staging testrole
[bbs-evolution.ipsw.dt.ept.lu] Executing task 'testrole'
['staging']

Done.

Or:

› fab -R staging,prod testrole
[bbs-evolution.ipsw.dt.ept.lu] Executing task 'testrole'
['staging', 'prod']
[bbs-arbiter.ipsw.dt.ept.lu] Executing task 'testrole'
['staging', 'prod']

Done.

With this, we can do a simple in test in a fabric task:

@fab.task
def testrole():
    if 'prod' in fab.env.roles:
        do_production_stuff()
    elif 'staging' in fab.env.roles:
        do_staging_stuff()
    else:
        raise ValueError('No valid role specified!')