Add test coverage for SAT-26014

[Gauravtalreja1]

Problem Statement

Missing test coverage for SAT-26014

Solution

Adding a destructive test to cover SAT-26014

Related Issues

[Gauravtalreja1]

trigger: test-robottelo
pytest: tests/foreman/destructive/test_installer.py -k test_negative_installer_invalid_dns_forwarder

[Satellite-QE]

PRT Result

Build Number: 8823
Build Status: SUCCESS
PRT Comment: pytest tests/foreman/destructive/test_installer.py -k test_negative_installer_invalid_dns_forwarder --external-logging
Test Result : ========== 1 passed, 5 deselected, 18 warnings in 1252.58s (0:20:52) ===========

[rmynar]

Looks good to me.

Just non-blocking comments:
Would you consider adding a positive scenario? It may be easily added into non-default installation:

robottelo/tests/foreman/installer/test_installer.py

Line 296 in 8109a0f

installer_args = [

What about cherry picking into older versions? 6.15, maybe 6.14...?

[Gauravtalreja1]

@rmynar Thanks for your comments.
If you see the related issue, then its about a negative scenario only which breaks the answer file, and for positive scenario its already been tested in our misc-provisioning Jenkins jobs, so I don't think if we should cover in new test separately, and about cherrypicking it to 6.15 or 6.14, so its only fixed for stream and 6.16 for now.