Comment 7 for bug 1952008

Reviewed: https://review.opendev.org/c/starlingx/config/+/825545
Committed: https://opendev.org/starlingx/config/commit/d27a98bcb64a622798d87a74aa048bb50a664df8
Submitter: "Zuul (22348)"
Branch: master

commit d27a98bcb64a622798d87a74aa048bb50a664df8
Author: Rafael Camargos <email address hidden>
Date: Tue Nov 23 21:18:31 2021 -0300

    Add validation of special chars on system values

    Setting a system value with special characters will get sysinv in a
    dirty state and unreachable. E.g.: `system modify -n='º'`. This is
    caused because isystem DB won't accept these special chars.

    This work adds a validation on the PATCH method of the SystemController
    blocking any special character on string fields that is not accepted.

    Test Plan:

    PASS: Verify special characters are not accepted as system values
    PASS: Verify system works properly after setting a value with any of the
    accepted characters: 'a-zA-Z0-9!@#$%^&*()_+-=[]{};:'"|,.<>/? '
    PASS: Verify system https_enabled can be properly toggled
    PASS: Verify validation works properly in Python 3 (tested code snippet)
    PASS: Verify validation is bypassed for non-strings objects

    Regression:

    PASS: Verify system install

    Closes-Bug: 1952008
    Signed-off-by: Rafael Camargos <email address hidden>
    Change-Id: If73cc2bfa881df3e46611178759ca2527d83330b