Fixes #20298: Add placeholder for failed image thumbnail generation #1242

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MrUnknownDE · 2026-04-05T22:31:51+02:00

MrUnknownDE commented

2026-04-05 22:31:51 +02:00

Originally created by @jnovinger on 9/15/2025

Fixes: #20298

When Redis cache lacks disk persistence sorl-thumbnail fails to generate thumbnails, leaving only bare filename text visible. This adds an {% empty %} fallback block to the thumbnail template that displays a placeholder with a broken image icon and user instructions when thumbnail generation fails.

The placeholder maintains the expected 200x200px dimensions and provides:

Broken image icon (mdi-image-broken-variant)
Error message explaining the issue
Clickable link to view the original image
High contrast text (text-dark) for readability on light background

This can be tested by changing the permission on the thumbnail cache directory before adding a thumbnail, via chmod 444 netbox/media/cache. Just remember to change the permission back after testing.

*Originally created by @jnovinger on 9/15/2025* ### Fixes: #20298 When Redis cache lacks disk persistence `sorl-thumbnail` fails to generate thumbnails, leaving only bare filename text visible. This adds an `{% empty %}` fallback block to the thumbnail template that displays a placeholder with a broken image icon and user instructions when thumbnail generation fails. The placeholder maintains the expected 200x200px dimensions and provides: - Broken image icon (`mdi-image-broken-variant`) - Error message explaining the issue - Clickable link to view the original image - High contrast text (`text-dark`) for readability on light background This can be tested by changing the permission on the thumbnail cache directory before adding a thumbnail, via `chmod 444 netbox/media/cache`. Just remember to change the permission back after testing.

MrUnknownDE closed this issue

2026-04-05 22:31:51 +02:00

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Reference: github/netbox#1242