ALLOWED_URL_SCHEMES not honoured for custom fields of type 'URL'

[candlerb]

NetBox version

v3.1.5

Python version

3.8

Steps to Reproduce

0. Ensure ALLOWED_URL_SCHEMES is not set in configuration.py
1. Create a custom field
   • name 'blah'
   • type 'URL'
   • content types 'DCIM > Device'
2. Browse to a device
3. Enter URL ssh://foo into the blah custom field (also try ssh://foo/, ssh://foo/bar)

Expected Behavior

URL to be accepted, since the default is:

        default=(
            'file', 'ftp', 'ftps', 'http', 'https', 'irc', 'mailto', 'sftp', 'ssh', 'tel', 'telnet', 'tftp', 'vnc',
            'xmpp',
        ),

Observed Behavior

Errors

Blah

• Enter a valid URL.

---

Note also that http://foo is accepted but file://foo is not

[jeremystretch]

Thanks @candlerb!

[candlerb]

This looks like a silly bug. But when I make the obvious change (EDIT: first version was wrong):

--- a/netbox/utilities/validators.py
+++ b/netbox/utilities/validators.py
@@ -23,8 +23,7 @@ class EnhancedURLValidator(URLValidator):

     def __init__(self, schemes=None, **kwargs):
         super().__init__(**kwargs)
-        if schemes is not None:
-            self.schemes = get_config().ALLOWED_URL_SCHEMES
+        self.schemes = schemes or get_config().ALLOWED_URL_SCHEMES


 class ExclusionValidator(BaseValidator):

Netbox fails to start due to a circular import:

Jan 11 20:07:59 netbox3 gunicorn[101352]: [2022-01-11 20:07:59 +0000] [101352] [ERROR] Exception in worker process
Jan 11 20:07:59 netbox3 gunicorn[101352]: Traceback (most recent call last):
Jan 11 20:07:59 netbox3 gunicorn[101352]:   File "/opt/netbox/venv/lib/python3.8/site-packages/gunicorn/arbiter.py", line 589, in spawn_worker
Jan 11 20:07:59 netbox3 gunicorn[101352]:     worker.init_process()
Jan 11 20:07:59 netbox3 gunicorn[101352]:   File "/opt/netbox/venv/lib/python3.8/site-packages/gunicorn/workers/gthread.py", line 92, in init_process
Jan 11 20:07:59 netbox3 gunicorn[101352]:     super().init_process()
Jan 11 20:07:59 netbox3 gunicorn[101352]:   File "/opt/netbox/venv/lib/python3.8/site-packages/gunicorn/workers/base.py", line 134, in init_process
Jan 11 20:07:59 netbox3 gunicorn[101352]:     self.load_wsgi()
Jan 11 20:07:59 netbox3 gunicorn[101352]:   File "/opt/netbox/venv/lib/python3.8/site-packages/gunicorn/workers/base.py", line 146, in load_wsgi
Jan 11 20:07:59 netbox3 gunicorn[101352]:     self.wsgi = self.app.wsgi()
Jan 11 20:07:59 netbox3 gunicorn[101352]:   File "/opt/netbox/venv/lib/python3.8/site-packages/gunicorn/app/base.py", line 67, in wsgi
Jan 11 20:07:59 netbox3 gunicorn[101352]:     self.callable = self.load()
Jan 11 20:07:59 netbox3 gunicorn[101352]:   File "/opt/netbox/venv/lib/python3.8/site-packages/gunicorn/app/wsgiapp.py", line 58, in load
Jan 11 20:07:59 netbox3 gunicorn[101352]:     return self.load_wsgiapp()
Jan 11 20:07:59 netbox3 gunicorn[101352]:   File "/opt/netbox/venv/lib/python3.8/site-packages/gunicorn/app/wsgiapp.py", line 48, in load_wsgiapp
Jan 11 20:07:59 netbox3 gunicorn[101352]:     return util.import_app(self.app_uri)
Jan 11 20:07:59 netbox3 gunicorn[101352]:   File "/opt/netbox/venv/lib/python3.8/site-packages/gunicorn/util.py", line 359, in import_app
Jan 11 20:07:59 netbox3 gunicorn[101352]:     mod = importlib.import_module(module)
Jan 11 20:07:59 netbox3 gunicorn[101352]:   File "/usr/lib/python3.8/importlib/__init__.py", line 127, in import_module
Jan 11 20:07:59 netbox3 gunicorn[101352]:     return _bootstrap._gcd_import(name[level:], package, level)
Jan 11 20:07:59 netbox3 gunicorn[101352]:   File "<frozen importlib._bootstrap>", line 1014, in _gcd_import
Jan 11 20:07:59 netbox3 gunicorn[101352]:   File "<frozen importlib._bootstrap>", line 991, in _find_and_load
Jan 11 20:07:59 netbox3 gunicorn[101352]:   File "<frozen importlib._bootstrap>", line 975, in _find_and_load_unlocked
Jan 11 20:07:59 netbox3 gunicorn[101352]:   File "<frozen importlib._bootstrap>", line 671, in _load_unlocked
Jan 11 20:07:59 netbox3 gunicorn[101352]:   File "<frozen importlib._bootstrap_external>", line 848, in exec_module
Jan 11 20:07:59 netbox3 gunicorn[101352]:   File "<frozen importlib._bootstrap>", line 219, in _call_with_frames_removed
Jan 11 20:07:59 netbox3 gunicorn[101352]:   File "/opt/netbox/netbox/netbox/wsgi.py", line 7, in <module>
Jan 11 20:07:59 netbox3 gunicorn[101352]:     application = get_wsgi_application()
Jan 11 20:07:59 netbox3 gunicorn[101352]:   File "/opt/netbox/venv/lib/python3.8/site-packages/django/core/wsgi.py", line 12, in get_wsgi_application
Jan 11 20:07:59 netbox3 gunicorn[101352]:     django.setup(set_prefix=False)
Jan 11 20:07:59 netbox3 gunicorn[101352]:   File "/opt/netbox/venv/lib/python3.8/site-packages/django/__init__.py", line 24, in setup
Jan 11 20:07:59 netbox3 gunicorn[101352]:     apps.populate(settings.INSTALLED_APPS)
Jan 11 20:07:59 netbox3 gunicorn[101352]:   File "/opt/netbox/venv/lib/python3.8/site-packages/django/apps/registry.py", line 114, in populate
Jan 11 20:07:59 netbox3 gunicorn[101352]:     app_config.import_models()
Jan 11 20:07:59 netbox3 gunicorn[101352]:   File "/opt/netbox/venv/lib/python3.8/site-packages/django/apps/config.py", line 301, in import_models
Jan 11 20:07:59 netbox3 gunicorn[101352]:     self.models_module = import_module(models_module_name)
Jan 11 20:07:59 netbox3 gunicorn[101352]:   File "/usr/lib/python3.8/importlib/__init__.py", line 127, in import_module
Jan 11 20:07:59 netbox3 gunicorn[101352]:     return _bootstrap._gcd_import(name[level:], package, level)
Jan 11 20:07:59 netbox3 gunicorn[101352]:   File "<frozen importlib._bootstrap>", line 1014, in _gcd_import
Jan 11 20:07:59 netbox3 gunicorn[101352]:   File "<frozen importlib._bootstrap>", line 991, in _find_and_load
Jan 11 20:07:59 netbox3 gunicorn[101352]:   File "<frozen importlib._bootstrap>", line 975, in _find_and_load_unlocked
Jan 11 20:07:59 netbox3 gunicorn[101352]:   File "<frozen importlib._bootstrap>", line 671, in _load_unlocked
Jan 11 20:07:59 netbox3 gunicorn[101352]:   File "<frozen importlib._bootstrap_external>", line 848, in exec_module
Jan 11 20:07:59 netbox3 gunicorn[101352]:   File "<frozen importlib._bootstrap>", line 219, in _call_with_frames_removed
Jan 11 20:07:59 netbox3 gunicorn[101352]:   File "/opt/netbox/netbox/circuits/models/__init__.py", line 1, in <module>
Jan 11 20:07:59 netbox3 gunicorn[101352]:     from .circuits import *
Jan 11 20:07:59 netbox3 gunicorn[101352]:   File "/opt/netbox/netbox/circuits/models/circuits.py", line 7, in <module>
Jan 11 20:07:59 netbox3 gunicorn[101352]:     from dcim.models import LinkTermination
Jan 11 20:07:59 netbox3 gunicorn[101352]:   File "/opt/netbox/netbox/dcim/models/__init__.py", line 1, in <module>
Jan 11 20:07:59 netbox3 gunicorn[101352]:     from .cables import *
Jan 11 20:07:59 netbox3 gunicorn[101352]:   File "/opt/netbox/netbox/dcim/models/cables.py", line 16, in <module>
Jan 11 20:07:59 netbox3 gunicorn[101352]:     from utilities.fields import ColorField
Jan 11 20:07:59 netbox3 gunicorn[101352]:   File "/opt/netbox/netbox/utilities/fields.py", line 5, in <module>
Jan 11 20:07:59 netbox3 gunicorn[101352]:     from .forms import ColorSelect
Jan 11 20:07:59 netbox3 gunicorn[101352]:   File "/opt/netbox/netbox/utilities/forms/__init__.py", line 2, in <module>
Jan 11 20:07:59 netbox3 gunicorn[101352]:     from .fields import *
Jan 11 20:07:59 netbox3 gunicorn[101352]:   File "/opt/netbox/netbox/utilities/forms/fields.py", line 107, in <module>
Jan 11 20:07:59 netbox3 gunicorn[101352]:     class LaxURLField(forms.URLField):
Jan 11 20:07:59 netbox3 gunicorn[101352]:   File "/opt/netbox/netbox/utilities/forms/fields.py", line 112, in LaxURLField
Jan 11 20:07:59 netbox3 gunicorn[101352]:     default_validators = [EnhancedURLValidator()]
Jan 11 20:07:59 netbox3 gunicorn[101352]:   File "/opt/netbox/netbox/utilities/validators.py", line 27, in __init__
Jan 11 20:07:59 netbox3 gunicorn[101352]:     self.schemes = get_config().ALLOWED_URL_SCHEMES
Jan 11 20:07:59 netbox3 gunicorn[101352]:   File "/opt/netbox/netbox/netbox/config/__init__.py", line 27, in get_config
Jan 11 20:07:59 netbox3 gunicorn[101352]:     _thread_locals.config = Config()
Jan 11 20:07:59 netbox3 gunicorn[101352]:   File "/opt/netbox/netbox/netbox/config/__init__.py", line 49, in __init__
Jan 11 20:07:59 netbox3 gunicorn[101352]:     self._populate_from_db()
Jan 11 20:07:59 netbox3 gunicorn[101352]:   File "/opt/netbox/netbox/netbox/config/__init__.py", line 77, in _populate_from_db
Jan 11 20:07:59 netbox3 gunicorn[101352]:     from extras.models import ConfigRevision
Jan 11 20:07:59 netbox3 gunicorn[101352]:   File "/opt/netbox/netbox/extras/models/__init__.py", line 2, in <module>
Jan 11 20:07:59 netbox3 gunicorn[101352]:     from .configcontexts import ConfigContext, ConfigContextModel
Jan 11 20:07:59 netbox3 gunicorn[101352]:   File "/opt/netbox/netbox/extras/models/configcontexts.py", line 7, in <module>
Jan 11 20:07:59 netbox3 gunicorn[101352]:     from extras.querysets import ConfigContextQuerySet
Jan 11 20:07:59 netbox3 gunicorn[101352]:   File "/opt/netbox/netbox/extras/querysets.py", line 4, in <module>
Jan 11 20:07:59 netbox3 gunicorn[101352]:     from extras.models.tags import TaggedItem
Jan 11 20:07:59 netbox3 gunicorn[101352]:   File "/opt/netbox/netbox/extras/models/tags.py", line 9, in <module>
Jan 11 20:07:59 netbox3 gunicorn[101352]:     from utilities.fields import ColorField
Jan 11 20:07:59 netbox3 gunicorn[101352]: ImportError: cannot import name 'ColorField' from partially initialized module 'utilities.fields' (most likely due to a circular import) (/opt/netbox/netbox/utilities/fields.py)

[jeremystretch]

Yeah, it just needs a bit of refactoring to load the allowed schemes after the config has been initialized.