Add function to load YAML files

This commit starts to remove some code redundancy from the startup
scripts for easier maintenance.

startup_scripts/220_prefixes.py

@@ -2,53 +2,45 @@ from dcim.models import Site
 from ipam.models import Prefix, VLAN, Role, VRF
 from tenancy.models import Tenant, TenantGroup
 from extras.models import CustomField, CustomFieldValue
-from ruamel.yaml import YAML
-
 from netaddr import IPNetwork
-from pathlib import Path
+from startup_script_utils import load_yaml
 import sys
 
-file = Path('/opt/netbox/initializers/prefixes.yml')
-if not file.is_file():
+prefixes = load_yaml('/opt/netbox/initializers/prefixes.yml')
+
+if prefixes is None:
   sys.exit()
 
-with file.open('r') as stream:
-  yaml = YAML(typ='safe')
-  prefixes = yaml.load(stream)
+optional_assocs = {
+  'site': (Site, 'name'),
+  'tenant': (Tenant, 'name'),
+  'tenant_group': (TenantGroup, 'name'),
+  'vlan': (VLAN, 'name'),
+  'role': (Role, 'name'),
+  'vrf': (VRF, 'name')
+}
 
-  optional_assocs = {
-    'site': (Site, 'name'),
-    'tenant': (Tenant, 'name'),
-    'tenant_group': (TenantGroup, 'name'),
-    'vlan': (VLAN, 'name'),
-    'role': (Role, 'name'),
-    'vrf': (VRF, 'name')
-  }
+for params in prefixes:
+  custom_fields = params.pop('custom_fields', None)
+  params['prefix'] = IPNetwork(params['prefix'])
 
-  if prefixes is not None:
-    for params in prefixes:
-      custom_fields = params.pop('custom_fields', None)
-      params['prefix'] = IPNetwork(params['prefix'])
+  for assoc, details in optional_assocs.items():
+    if assoc in params:
+      model, field = details
+      query = { field: params.pop(assoc) }
+      params[assoc] = model.objects.get(**query)
 
-      for assoc, details in optional_assocs.items():
-        if assoc in params:
-          model, field = details
-          query = { field: params.pop(assoc) }
+  prefix, created = Prefix.objects.get_or_create(**params)
 
-          params[assoc] = model.objects.get(**query)
+  if created:
+    if custom_fields is not None:
+      for cf_name, cf_value in custom_fields.items():
+        custom_field = CustomField.objects.get(name=cf_name)
+        custom_field_value = CustomFieldValue.objects.create(
+          field=custom_field,
+          obj=prefix,
+          value=cf_value
+        )
+        prefix.custom_field_values.add(custom_field_value)
 
-      prefix, created = Prefix.objects.get_or_create(**params)
-
-      if created:
-        if custom_fields is not None:
-          for cf_name, cf_value in custom_fields.items():
-            custom_field = CustomField.objects.get(name=cf_name)
-            custom_field_value = CustomFieldValue.objects.create(
-              field=custom_field,
-              obj=prefix,
-              value=cf_value
-            )
-
-            prefix.custom_field_values.add(custom_field_value)
-
-        print("📌 Created Prefix", prefix.prefix)
+    print("📌 Created Prefix", prefix.prefix)