Cache

Dagger caches two types of data:

1. Layers: This refers to build instructions and the results of some API calls.
2. Volumes: This refers to the contents of a Dagger filesystem volume and is persisted across Dagger Engine sessions.

Cache inspection

• Show all the cache entry metadata:

dagger core engine local-cache entry-set entries

• Show high level summaries of cache usage:

dagger core engine local-cache entry-set

Garbage collection

The cache garbage collector runs in the background of the dagger engine, looking for unused layers and artifacts, and clears them up once they exceed the storage allowed by the cache policy.

The default cache policy attempts to keep the long-term cache storage under 75% of the total disk, while also ensuring that at least 20% of the disk remains free for other applications and tools.

The cache policy can be manually configured using the engine config.

Manual pruning

To manually free up disk space used by the cache, use the following command:

dagger core engine local-cache prune