Umbraco.Community.ImageSharp.TrimCache 1.0.2

Umbraco.Community.ImageSharp.TrimCache

Scheduled, age-based trimming of the ImageSharp.Web image cache for Umbraco. Supports both the Azure Blob cache and the local physical cache, and runs in the background as a hosted service.

The ImageSharp cache accumulates resized image variants that are never cleared automatically — on Umbraco Cloud (or any blob-backed site) it can grow until it exceeds the plan's media-storage limit. This package trims those variants by age, on a schedule. Deleting a variant is safe: it is simply regenerated from the original media on the next request. The trimmer only scans the cache location you configure, so keep that separate from source media — in Azure mode, point it at a cache-only container, never the media container.

Supports Umbraco 13, 17 and 18.

Installation

dotnet add package Umbraco.Community.ImageSharp.TrimCache

The hosted service is wired up automatically — no manual registration needed. By default it trims the local physical cache; if Azure blob storage is configured it trims the Azure cache instead.

Configuration

Add an ImageCacheTrim section to appsettings.json (defaults shown):

"ImageCacheTrim": {
  "Enabled": true,
  "Mode": "Auto",
  "MaxAgeDays": 30,
  "IntervalMinutes": 1440,
  "StartupDelayMinutes": 5,
  "CacheFolderPath": "",
  "ConnectionString": "",
  "ContainerName": "",
  "Prefix": ""
}

• Mode — Auto (default), Local or Azure.
• MaxAgeDays — entries older than this are deleted (regenerated on next request).
• IntervalMinutes — run frequency, measured from startup. Default 1440 (24h).
• CacheFolderPath — local mode only; leave empty (the default) to follow Umbraco's configured ImageSharp cache folder (Umbraco:CMS:Imaging:Cache:CacheFolder).
• ConnectionString — required for Azure mode. An account connection string, or one carrying a SAS (BlobEndpoint=…;SharedAccessSignature=…) — the SAS form is how Umbraco Cloud exposes storage. The credential must allow List and Delete.
• Prefix — scopes the scan (e.g. cache/). Set it whenever the cache shares a container with other data (e.g. media): with an empty prefix the trimmer would delete the media too. Leave empty only for a dedicated cache-only container.
• RunOnEveryServer — load-balancing control; defaults to running on every server for a local (per-server) cache and only the scheduling server for a shared Azure cache.

Umbraco Cloud: set Mode: "Azure", put the SAS connection string in ConnectionString (with ContainerName), and set Prefix to the cache subfolder (e.g. cache/) so media in the same container is never trimmed. See the project README for details.

See the project README for full documentation.

Author

Created and maintained by Justin Neville at Nevitech IT Solutions Ltd.

Credits

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