Catch import errors during backend init

.github/workflows/ci.yml

@@ -60,7 +60,6 @@ jobs:
       run: |
         python -m pip install --upgrade pip
         pip install -r requirements.txt
-        pip install boto3 dulwich
         pip install pycodestyle coverage tblib
 
     - name: Build documentation

netbox/core/data_backends.py

@@ -54,13 +54,6 @@ class DataBackend:
         """
         return
 
-    def handle_missing_dependency(self, e):
-        """
-        Hook for handling exceptions related to the attempted import of missing modules. Returns an exception
-        to be raised.
-        """
-        return e
-
     @property
     def url_scheme(self):
         return urlparse(self.url).scheme.lower()
@@ -105,10 +98,7 @@ class GitBackend(DataBackend):
     sensitive_parameters = ['password']
 
     def init_config(self):
-        try:
+        from dulwich.config import ConfigDict
-            from dulwich.config import ConfigDict
-        except ModuleNotFoundError as e:
-            raise self.handle_missing_dependency(e)
 
         # Initialize backend config
         config = ConfigDict()
@@ -120,18 +110,9 @@ class GitBackend(DataBackend):
 
         return config
 
-    def handle_missing_dependency(self, e):
-        return ImportError(_(
-            "Unable to initialize the git data backend: dulwich library is not installed. Run 'pip install dulwich' "
-            "within the NetBox Python environment to install it."
-        ))
-
     @contextmanager
     def fetch(self):
-        try:
+        from dulwich import porcelain
-            from dulwich import porcelain
-        except ModuleNotFoundError as e:
-            raise self.handle_missing_dependency(e)
 
         local_path = tempfile.TemporaryDirectory()
 
@@ -179,28 +160,16 @@ class S3Backend(DataBackend):
     REGION_REGEX = r's3\.([a-z0-9-]+)\.amazonaws\.com'
 
     def init_config(self):
-        try:
+        from botocore.config import Config as Boto3Config
-            from botocore.config import Config as Boto3Config
-        except ModuleNotFoundError as e:
-            raise self.handle_missing_dependency(e)
 
         # Initialize backend config
         return Boto3Config(
             proxies=settings.HTTP_PROXIES,
         )
 
-    def handle_missing_dependency(self, e):
-        return ImportError(_(
-            "Unable to initialize the Amazon S3 backend: boto3 library is not installed. Run 'pip install boto3' "
-            "within the NetBox Python environment to install it."
-        ))
-
     @contextmanager
     def fetch(self):
-        try:
+        import boto3
-            import boto3
-        except ModuleNotFoundError as e:
-            raise self.handle_missing_dependency(e)
 
         local_path = tempfile.TemporaryDirectory()
 

netbox/core/models/data.py

@@ -151,7 +151,7 @@ class DataSource(JobsMixin, PrimaryModel):
         Create/update/delete child DataFiles as necessary to synchronize with the remote source.
         """
         if self.status == DataSourceStatusChoices.SYNCING:
-            raise SyncError(f"Cannot initiate sync; syncing already in progress.")
+            raise SyncError("Cannot initiate sync; syncing already in progress.")
 
         # Emit the pre_sync signal
         pre_sync.send(sender=self.__class__, instance=self)
@@ -160,7 +160,10 @@ class DataSource(JobsMixin, PrimaryModel):
         DataSource.objects.filter(pk=self.pk).update(status=self.status)
 
         # Replicate source data locally
-        backend = self.get_backend()
+        try:
+            backend = self.get_backend()
+        except ModuleNotFoundError as e:
+            raise SyncError(f"There was an error initializing the backend: {e}")
         with backend.fetch() as local_path:
 
             logger.debug(f'Syncing files from source root {local_path}')