b3df7f8a3d
Document the nix-cache-info file format used by binary caches, including the StoreDir, WantMassQuery, and Priority fields, their behavior, and links to related store options.
1.5 KiB
1.5 KiB
Nix Cache Info Format
The nix-cache-info file is a metadata file at the root of a binary cache (e.g., https://cache.example.com/nix-cache-info).
MIME type: text/x-nix-cache-info
Format
Line-based key-value format:
Key: value
Leading and trailing whitespace is trimmed from values. Lines without a colon are ignored. Unknown keys are silently ignored.
Fields
StoreDir
The Nix store directory path that this cache was built for (e.g., /nix/store).
If present, Nix verifies that this matches the client's store directory:
error: binary cache 'https://example.com' is for Nix stores with prefix '/nix/store', not '/home/user/nix/store'
WantMassQuery
1 or 0. Sets the default for want-mass-query.
Priority
Integer. Sets the default for priority.
Example
StoreDir: /nix/store
WantMassQuery: 1
Priority: 30
Caching Behavior
Nix caches nix-cache-info in the cache directory with a 7-day TTL.