Re: [Fab-user] with_settings decorator generating RuntimeError (generato

Hi Carlos,

Yes, if I do that it works (in fact that’s how it was before):

def _my_function():

with settings(hide("status")):

try:

out = run("uname")

puts("OS is " + out)

except SystemExit:

puts("can't get the OS")

However having to indent the whole function body just because I want to hide the status messages is weird, especially after reading this:

“Allows you to wrap an entire function as if it was called inside a block with the settings context manager. This may be useful if you know you want a given setting applied to an entire function body...” (source: http://docs.fabfile.org/en/latest/api/core/decorators.html#fabric.decorators.with_settings).

Which is exactly what I want.

Anyway, maybe I should just do that and move on, but it’s kind of frustrating.

Moreover, now I’m curious about why this error is happening and I’m sure there is a learning opportunity there for me. ;)

Thanks,

Felix

From: Carlos García [mailto:address@hidden
Sent: Thursday, March 12, 2015 5:04 AM
To: Felix Almeida
Cc: address@hidden
Subject: Re: [Fab-user] with_settings decorator generating RuntimeError (generator didn't yield)

Hi Felix,

Have you try to use a context manager instead of the decorator? I´m not really sure if you can use it as a decorator...

def _my_function():

with_settings(hide("status")):

try:

out = run("uname")

puts("OS is " + out)

except SystemExit:

puts("can't get the OS")

That's the way I'm using it in my scripts and it seems to work, but we're using it just for Ubuntu and CentOS...

Keep us posted

Regards!

2015-03-12 0:53 GMT+01:00 Felix Almeida <address@hidden>:

Hi all,

I need to validate if a certain UNIX account is able to log in to a series of servers of mixed flavors (HP-UX, Solaris, RHEL and AIX) so I’m trying to do it with fabric.

I wanted to apply hide("status") to an entire internal function, but I keep getting the following error:

elxin009: ~/fabric # fab main

[bsnbk001] out: SunOS

[bsnbk001] out:

[bsnbk001] OS is SunOS

Disconnecting from bsnbk001... done.

Traceback (most recent call last):

File "/usr/local/lib/python2.7/site-packages/fabric/main.py", line 743, in main

*args, **kwargs

File "/usr/local/lib/python2.7/site-packages/fabric/tasks.py", line 424, in execute

results['<local-only>'] = task.run(*args, **new_kwargs)

File "/usr/local/lib/python2.7/site-packages/fabric/tasks.py", line 174, in run

return self.wrapped(*args, **kwargs)

File "/home/felix/fabric/fabfile.py", line 24, in main

execute(_my_function, hosts=host_list)

File "/usr/local/lib/python2.7/site-packages/fabric/tasks.py", line 384, in execute

multiprocessing

File "/usr/local/lib/python2.7/site-packages/fabric/tasks.py", line 274, in _execute

return task.run(*args, **kwargs)

File "/usr/local/lib/python2.7/site-packages/fabric/tasks.py", line 174, in run

return self.wrapped(*args, **kwargs)

File "/usr/local/lib/python2.7/site-packages/fabric/decorators.py", line 215, in inner

with settings(*arg_settings, **kw_settings):

File "/usr/local/lib/python2.7/contextlib.py", line 17, in __enter__

return self.gen.next()

File "/usr/local/lib/python2.7/contextlib.py", line 112, in nested

vars.append(enter())

File "/usr/local/lib/python2.7/contextlib.py", line 19, in __enter__

raise RuntimeError("generator didn't yield")

RuntimeError: generator didn't yield

This is a very simplified version of my original code that I’m using for troubleshooting since it generates the same error:

from fabric.api import task, hide, execute, env, puts, run, with_settings

env.use_shell = False

env.disable_known_hosts = True

env.warn_only = True

env.abort_on_prompts = True

env.skip_bad_hosts = True

env.command_timeout = 3

env.eagerly_disconnect = True

env.always_use_pty = False

@with_settings(hide("status"))

def _my_function():

try:

out = run("uname")

puts("OS is " + out)

except SystemExit:

puts("can't get the OS")

@task

def main():

host_list = [line.rstrip("\n") for line in open("hosts.txt")]

with hide("running"):

execute(_my_function, hosts=host_list)

The hosts.txt file is just a text file with one hostname per line. This was the content of the file when I captured the output above (just two servers):

bsnbk001

slxap003

In fact, none of the env settings makes any difference, but if I comment out the @with_settings line it works as expected. If the hosts.txt file contains only one hostname then it also works without any errors.

Please, any ideas of what I am doing wrong? I’m still learning Python so forgive me if I’m doing something silly.

Thank you,

Felix

PS: I’m running Fabric 1.10.1 and Paramiko 1.15.2 on RHEL.

From:	Felix Almeida
Subject:	Re: [Fab-user] with_settings decorator generating RuntimeError (generator didn't yield)
Date:	Thu, 12 Mar 2015 14:20:47 +0000