[Fab-user] How to set target hosts in Fabric file ?

[Steven Samuel Cole]

I want to use Fabric to deploy my web app code to development, staging 
and production servers. My fabfile:

def deploy_2_dev():
  deploy('dev')

def deploy_2_staging():
  deploy('staging')

def deploy_2_prod():
  deploy('prod')

def deploy(server):
  print 'env.hosts:', env.hosts
  env.hosts = [server]
  print 'env.hosts:', env.hosts
  # do some deployment work (omitted)

Sample output:

host:folder user$ fab deploy_2_dev
env.hosts: []
env.hosts: ['dev']
No hosts found. Please specify (single) host string for connection:

When I create a set_hosts() task as shown in the Fabric docs, env.hosts 
is set properly. However, this is not a viable option, neither is a 
decorator. Passing hosts on the command line would ultimately result in 
some kind of shell script that calls the fabfile, I would prefer having 
one single tool do the job properly.

It says in the Fabric docs that 'env.hosts is simply a Python list 
object'. From my observations, this is simply not true.

Can anyone explain what is going on here ? How can I set the host to 
deploy to ? I am using Fabric 0.9.