如何为每个任务隔离结构中的环境主机的用户输入

Question

I have a few tasks in a fabric script. I'm trying to figure out how one would allow for the setting of the env.hosts or the @hosts decorator to be isolated to a given task. I want to have some tasks in my fab file to have preset hosts while I could feed a file that could be parsed as a tuple of hosts to others. I would also like to have that file determined at run time.

I have this:

def host_list():
    host_file = raw_input("enter the file containing the list of hosts: ")
    host_list = open(host_file, 'r')
    host_list = host_list.read().strip('\n')
    host_list = host_list.split(',')

    return host_list

I have a task:

@task
def hostname():
    run('hostname')

I can get env.hosts set properly when I have the host_list function separated into commands, but I have other tasks I don't want to have fabric prompt to set env.hosts. I tried adding the steps inside the task functions, but I get prompted with every iteration. I tried to feed the #hosts decorator with the host_list function, but it gave me an error about the function object not being iterable. Is there a way to isolate the host_list function to only certain tasks?

Answer 1

There are plenty of questions in stack overflow with this answer. But to give you an idea, you could send the file as an argument to host_list(), and then read it, and pass it's results to use with the execute()