Move "rebuild_thumbnails" to being a management command

- Does not run every time the server reboots
- Has to be called manually
- Normally does not need to be run and is a long-running process!

InvenTree/InvenTree/management/commands/rebuild_thumbnails.py

@@ -0,0 +1,70 @@
+"""
+Custom management command to rebuild thumbnail images
+
+- May be required after importing a new dataset, for example
+"""
+
+import os
+import logging
+
+from PIL import UnidentifiedImageError
+
+from django.core.management.base import BaseCommand
+from django.conf import settings
+from django.db.utils import OperationalError, ProgrammingError
+
+from company.models import Company
+from part.models import Part
+
+
+logger = logging.getLogger("inventree-thumbnails")
+
+
+class Command(BaseCommand):
+    """
+    Rebuild all thumbnail images
+    """ 
+
+    def rebuild_thumbnail(self, model):
+        """
+        Rebuild the thumbnail specified by the "image" field of the provided model
+        """
+
+        if not model.image:
+            return
+
+        img = model.image
+        url = img.thumbnail.name
+        loc = os.path.join(settings.MEDIA_ROOT, url)
+        
+        if not os.path.exists(loc):
+            logger.info(f"Generating thumbnail image for '{img}'")
+
+            try:
+                model.image.render_variations(replace=False)
+            except FileNotFoundError:
+                logger.error(f"ERROR: Image file '{img}' is missing")
+            except UnidentifiedImageError:
+                logger.error(f"ERROR: Image file '{img}' is not a valid image")
+
+    def handle(self, *args, **kwargs):
+
+        logger.setLevel(logging.INFO)
+
+        logger.info("Rebuilding Part thumbnails")
+
+        for part in Part.objects.exclude(image=None):
+            try:
+                self.rebuild_thumbnail(part)
+            except (OperationalError, ProgrammingError):
+                logger.error("ERROR: Database read error.")
+                break
+
+        logger.info("Rebuilding Company thumbnails")
+
+        for company in Company.objects.exclude(image=None):
+            try:
+                self.rebuild_thumbnail(company)
+            except (OperationalError, ProgrammingError):
+                logger.error("ERROR: abase read error.")
+                break

InvenTree/company/apps.py

@@ -23,29 +23,4 @@ class CompanyConfig(AppConfig):
         This function is called whenever the Company app is loaded.
         """
 
-        if canAppAccessDatabase():
-            self.generate_company_thumbs()
-
-    def generate_company_thumbs(self):
-
-        from .models import Company
-
-        logger.debug("Checking Company image thumbnails")
-
-        try:
-            for company in Company.objects.all():
-                if company.image:
-                    url = company.image.thumbnail.name
-                    loc = os.path.join(settings.MEDIA_ROOT, url)
-
-                    if not os.path.exists(loc):
-                        logger.info("InvenTree: Generating thumbnail for Company '{c}'".format(c=company.name))
-                        try:
-                            company.image.render_variations(replace=False)
-                        except FileNotFoundError:
-                            logger.warning(f"Image file '{company.image}' missing")
-                        except UnidentifiedImageError:
-                            logger.warning(f"Image file '{company.image}' is invalid")
-        except (OperationalError, ProgrammingError):
-            # Getting here probably meant the database was in test mode
-            pass
+        pass

InvenTree/part/apps.py

@@ -24,40 +24,8 @@ class PartConfig(AppConfig):
         """
 
         if canAppAccessDatabase():
-            self.generate_part_thumbnails()
             self.update_trackable_status()
 
-    def generate_part_thumbnails(self):
-        """
-        Generate thumbnail images for any Part that does not have one.
-        This function exists mainly for legacy support,
-        as any *new* image uploaded will have a thumbnail generated automatically.
-        """
-
-        from .models import Part
-
-        logger.debug("InvenTree: Checking Part image thumbnails")
-
-        try:
-            # Only check parts which have images
-            for part in Part.objects.exclude(image=None):
-                if part.image:
-                    url = part.image.thumbnail.name
-                    loc = os.path.join(settings.MEDIA_ROOT, url)
-
-                    if not os.path.exists(loc):
-                        logger.info("InvenTree: Generating thumbnail for Part '{p}'".format(p=part.name))
-                        try:
-                            part.image.render_variations(replace=False)
-                        except FileNotFoundError:
-                            logger.warning(f"Image file '{part.image}' missing")
-                            pass
-                        except UnidentifiedImageError:
-                            logger.warning(f"Image file '{part.image}' is invalid")
-        except (OperationalError, ProgrammingError):
-            # Exception if the database has not been migrated yet
-            pass
-
     def update_trackable_status(self):
         """
         Check for any instances where a trackable part is used in the BOM