Two new features for the napalm configuration management: commit_in and commit_at

[mirceaulinic]

What does this PR do?

In the networking world, there are a very small number of platforms that allow you to commit a specific configuration change at a desired time. Although this is not particularly one of the best practices, turns out to be important sometimes (very rarely though). Nevertheless it is and will forever be optional.

With these changes, I am adding support for commit_in and commit_at to commit the config changes later. This simply leverages the abilities of the Salt scheduler, by adding a job to be executed once, at the time requested by the user. Therefore, this is available for any network platform managed through NAPALM, regardless if they do or don't support scheduled commit capabilities.

For safety reasons, I am adding the net.cancel_commit counterpart execution function to discard a scheduled commit.

Example:

# salt veos net.load_config text='ntp server 4.3.2.1' commit_in=2m
veos:
    ----------
    already_configured:
        False
    comment:
        Changes discarded for now, and scheduled commit at: 2018-07-26T10:06:33.
        The commit ID is: 20180726100429648495.
        To discard this commit, you can execute:

        salt veos net.cancel_commit 20180726100429648495
    diff:
        @@ -5,6 +5,7 @@
         transceiver qsfp default-mode 4x10G
         !
         ntp server 1.2.3.4
        +ntp server 4.3.2.1
         ntp server 5.6.7.8
         ntp server 10.10.10.1
         !
    loaded_config:
    result:
        True

[rallytime]

Hi @mirceaulinic - this is causing some related tests to fail. Can you take a look?

https://jenkinsci.saltstack.com/job/pr-kitchen-ubuntu1604-py2/job/PR-48779/1/

[rallytime]

This looks good to me, pending tests.

[gtmanfred]

this looks awesome!

[rallytime]

@mirceaulinic There are 2 tests failing with this change:

https://jenkinsci.saltstack.com/job/pr-kitchen-ubuntu1604-py2/job/PR-48779/1/

[mirceaulinic]

Hi @rallytime - I have corrected that error, please let me know if there's anything else. Thanks!

[rallytime]

Looks good now! Thanks @mirceaulinic!