Add support to send data on standard input when executing a command

[ghost]

When running a command via SSH, one may need to send data on the standard input of the command. This PR adds a stdin argument to exec and suexec methods, with a default value of nil. The data is sent only if this is not nil, so current calls to these methods should not be impacted.

Associated RHBZ: https://bugzilla.redhat.com/show_bug.cgi?id=1634029

[miq-bot]

Checked commit fabiendupont@fd9cb28 with ruby 2.3.3, rubocop 0.52.1, haml-lint 0.20.0, and yamllint 1.10.0
1 file checked, 2 offenses detected

lib/gems/pending/util/MiqSshUtil.rb

• ❗ - Line 109, Col 23 - Naming/VariableName - Use snake_case for variable names.
• ❗ - Line 50, Col 17 - Naming/VariableName - Use snake_case for variable names.

[carbonin]

Can you reference a WIP patch where this would be used? It's hard to review without seeing the use case.

[ghost]

@carbonin it would be used like this https://github.com/ManageIQ/manageiq/blob/7de90d65d5069ad4a1cb2a9eb3695b739ad00f3d/app/models/conversion_host.rb#L47.

In Automate, I had implemented a method similar to exec and suexec, and allowing passing data on stdin: https://github.com/ManageIQ/manageiq-content/blob/master/content/automate/ManageIQ/Transformation/TransformationHosts/ovirt_host.class/__methods__/utils.rb#L11-L42.

[carbonin]

@fdupont-redhat Does this need to go back to the Hammer release?

[ghost]

@carbonin Yes, it does. ManageIQ/manageiq#18064 expected to be backported to Hammer, so this one should too.

[simaishi]

Hammer backport details:

$ git log -1
commit 4bdf685aa5d00c518fc0a249b23cd7bba6b6cc16
Author: Nick Carboni <ncarboni@redhat.com>
Date:   Mon Oct 8 09:18:40 2018 -0400

    Merge pull request #379 from fdupont-redhat/add_support_for_stdin_to_ssh_exec
    
    Add support to send data on standard input when executing a command
    
    (cherry picked from commit 7cfbbb04a4d6c6b6e4c2b18cd1553d33d689b9b7)