Update plugin tutorial to align with NetBox 4.0 plugin API changes

[jeffgdotorg]

This tutorial needs some updates to bring it fully into line with the plugin API changes introduced in NetBox 4.0.

As a starting point, tutorial/step01-initial-setup.md still instructs the author to import from extras.plugins, instead of the new netbox.plugins package.

Refer to Migrating Your Plugin to NetBox 4.0 in the main NetBox docs for the full set of needed changes.

[agt-the-walker]

FWIW, I ran across the following issue in step09-rest-api.md (Step 9: REST API) against a development instance of Netbox (v4.2.1):

$ python3 manage.py runserver 0.0.0.0:8000 --insecure
[...]
  File "/home/agt/netbox-plugin-demo/netbox_access_lists/api/urls.py", line 2, in <module>
    from . import views
  File "/home/agt/netbox-plugin-demo/netbox_access_lists/api/views.py", line 6, in <module>
    from .serializers import AccessListSerializer, AccessListRuleSerializer
  File "/home/agt/netbox-plugin-demo/netbox_access_lists/api/serializers.py", line 3, in <module>
    from ipam.api.serializers import NestedPrefixSerializer
ImportError: cannot import name 'NestedPrefixSerializer' from 'ipam.api.serializers' (/opt/netbox/netbox/ipam/api/serializers.py). Did you mean: 'PrefixSerializer'?

The following change was enough to fix the problem (at first glance):

$ git diff remotes/origin/step09-rest-api -- ':!netbox_access_lists/__init__.py' ':!netbox_access_lists/navigation.py' ':!netbox_access_lists/migrations/0001_initial.py' ':!*.pyc'
diff --git a/netbox_access_lists/api/serializers.py b/netbox_access_lists/api/serializers.py
index 00c509e..4a58a92 100644
--- a/netbox_access_lists/api/serializers.py
+++ b/netbox_access_lists/api/serializers.py
@@ -1,6 +1,6 @@
 from rest_framework import serializers

-from ipam.api.serializers import NestedPrefixSerializer
+from ipam.api.serializers import PrefixSerializer
 from netbox.api.serializers import NetBoxModelSerializer, WritableNestedSerializer
 from ..models import AccessList, AccessListRule

@@ -52,8 +52,8 @@ class AccessListRuleSerializer(NetBoxModelSerializer):
         view_name='plugins-api:netbox_access_lists-api:accesslistrule-detail'
     )
     access_list = NestedAccessListSerializer()
-    source_prefix = NestedPrefixSerializer()
-    destination_prefix = NestedPrefixSerializer()
+    source_prefix = PrefixSerializer(nested=True)
+    destination_prefix = PrefixSerializer(nested=True)

     class Meta:
         model = AccessListRule

[deliciouslytyped]

I just spent half an hour on this wondering why my buttons weren't showing up, because /AFAICT/ netbox appears to have hidden whatever errors this causes.

As a starting point, tutorial/step01-initial-setup.md still instructs the author to import from extras.plugins, instead of the new netbox.plugins package.