Add ansible_shell_interpreter, or some other way to globally set the executable used by the shell module

[wknapik]

ISSUE TYPE

Feature Idea

COMPONENT NAME

shell

ANSIBLE VERSION

ansible 2.5.0
  config file = /etc/ansible/ansible.cfg
  configured module search path = [u'/home/foo/.ansible/plugins/modules', u'/usr/share/ansible/plugins/modules']
  ansible python module location = /usr/lib/python2.7/site-packages/ansible
  executable location = /usr/bin/ansible
  python version = 2.7.14 (default, Sep 20 2017, 01:25:59) [GCC 7.2.0]

2.5.0.34964.01091cddf6-1

CONFIGURATION

DEFAULT_STDOUT_CALLBACK(/etc/ansible/ansible.cfg) = debug

OS / ENVIRONMENT

N/A

SUMMARY

There should be a way to set the preferred shell executable globally, instead of having to do it in every single shell module invocation.

I have a bunch of roles here with a total of 39 shell tasks. Adding args: executable=bash in 39 places is just... wrong.

Also, it would be great to be able to set it to /usr/bin/env bash, instead of a path, like /usr/bin/bash, etc., since those vary between systems.

STEPS TO REPRODUCE

N/A

EXPECTED RESULTS

One global setting.

ACTUAL RESULTS

No global setting.

[ansibot]

Files identified in the description:

• lib/ansible/modules/commands/shell.py

If these files are inaccurate, please update the component name section of the description or use the !component bot command.

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[alikins]

There is a ansible_shell_executable (http://docs.ansible.com/ansible/latest/intro_inventory.html#list-of-behavioral-inventory-parameters). Would that work for your use case? If not, what is missing?

See also #24169 and related pr #31361 (and for more context, also the now reverted #24177

[wknapik]

Oh wow. I searched for this for quite a while and couldn't find it - not in the docs, not on google, not on irc...

Yes, ansible_shell_executable seems to be what I was looking for.

Why the inconsistent naming though ?

Also, could info about ansible_shell_executable be added here https://docs.ansible.com/ansible/latest/shell_module.html ?

Thanks!

[bcoca]

@wknapik that is different, the setting controls the shell used for executing modules, not the shell used by the shell module.

[wknapik]

@bcoca - well, you say that...

% ansible -m shell -a 'echo $0' localhost
localhost | SUCCESS | rc=0 >>
/bin/sh
% ansible -m shell -a 'echo $0' -e ansible_shell_executable=bash localhost
localhost | SUCCESS | rc=0 >>
bash
%

Works for me.

[bcoca]

i did not say it wouldn't work, but it is not 'on purpose', but a side effect, it was not meant as a default for the 'shell' module just what to use when executing modules.

[wknapik]

To me, that calls for the introduction of ansible_shell_interpreter, as I originally suggested.

If the current effect of ansible_shell_executable on the shell module were to change, the users who rely on this behavior would have to be given a reasonable way out...

I suppose few would actually need to execute all modules with shell X and use shell Y with the shell module, but for those few, ansible_shell_interpreter would be the only solution.

[bcoca]

this is a subset of 'defaults for modules' which we do not have a facility for.

closing as dupe/subset of ansible/proposals#81