Description of problem:

Remote execution fails with the "Password: su: Authentication failure" error when the "Effective User Method" method is set to "su"


Version-Release number of selected component (if applicable):

Red Hat Satellite 6.7


How reproducible:

Always

Steps to Reproduce:
1. Create a non-root user for remote execution on the content host and set the password for the user.
2. Do not copy keys or do any more configuration on the content host side.
3. On the Satellite GUI setup the following setting in "Administer >> Settings >> RemoteExecution":

   Effective User: root        
   Effective User Method: su
   SSH User: rexuser (here give the username of your non-root user)

4. Now try to execute the rex job on the content host and in the advance field provide appropriate values in the following fields:

   Password: <Password of your non-root user>
   Sudo password: <Password of the root user to perform su operation>   

5. Click on submit.

Actual results:

Below error is observed:

---
Password: su: Authentication failure
Exit status: 1
---


Expected results:

No error and successful execution of the job

Additional info: