New import_netbox_objectchange_json command

[chadell]

Addresses issue #39

In this PR:

• Moving some shared helper methods to nautobot_netbox_importer/command_utils.py to be reused by both commands (it was not possible to move to utils.py due circular dependency from adapters
• Adding logic to import ObjectChanges from Netbox to Nautobot, using the proper ContentType references, the user and the creation date.
• There is a dryrun mode to run the command without changing the database

TODO

• Add testing
• Add documentation

EXAMPLE

nautobot-server import_netbox_objectchange_json imp/script/netbox_no_changelog.json imp/script/netbox_only_changelog.json 2.10.3 --dry-run
12:54:05 info     Loading NetBox JSON data into memory...
  filename: {'imp/script/netbox_no_changelog.json'}
12:54:07 info     JSON data loaded into memory successfully.
12:54:07 info     Creating NetBox ContentType mapping...
12:54:07 info     Creating Nautobot ContentType mapping...
12:54:07 info     Loading ObjectChange NetBox JSON data into memory...
  filename: {'imp/script/netbox_only_changelog.json'}
  0%|                                                                                                   |      0/726784 [00:00]/opt/nautobot/lib/python3.8/site-packages/cacheops/redis.py:19: RuntimeWarning: The cacheops cache is unreachable! Error: Client sent AUTH, but no password is set
  warnings.warn("The cacheops cache is unreachable! Error: %s" % e, RuntimeWarning)
 50%|█████████████████████████████████████████████████▎                                                 | 361843/726784 [16:41]13:11:00 warning  ('ip_health_check', 'healthcheckrecord') key is not present in Nautobot
100%|███████████████████████████████████████████████████████████████████████████████████████████████████| 726784/726784 [17:16]
13:11:35 info     Processed 726784 in this run.

[glennmatthews]

Thank you for the pull request! I like the approach here a lot.

[glennmatthews]

netbox-docker, by default, prepends a few lines of text log output to any manage.py command, including manage.py dumpdata, which causes the resulting file to not be valid JSON until/unless you manually delete those lines with a text editor. I mention this just to suggest that you add a try...except ValueError around each of the json.load calls so that if the file isn't valid JSON, you can handle it gracefully with an appropriate error message.

[chadell]

thanks for the hint
btw, I believe that the same applies to https://github.com/nautobot/nautobot-plugin-netbox-importer/blob/develop/nautobot_netbox_importer/management/commands/import_netbox_json.py#L132

[glennmatthews]

What's the story behind the changes to poetry.lock? I don't see any corresponding changes to pyproject.toml.

[chadell]

What's the story behind the changes to poetry.lock? I don't see any corresponding changes to pyproject.toml.

terror story... I will rollback it

[glennmatthews]

Thanks for the updates!