Multiple Caches and Configuration Options in Buildx

Example `buildx` command using the `registry` backend, using import and export cache: ```console $ docker buildx build --push -t <registry>/<image> \ --cache-to type=registry,ref=<registry>/<cache-image>[,parameters...] \ --cache-from type=registry,ref=<registry>/<cache-image>[,parameters...] . ``` > [!WARNING] > > As a general rule, each cache writes to some location. No location can be > written to twice, without overwriting the previously cached data. If you want > to maintain multiple scoped caches (for example, a cache per Git branch), then > ensure that you use different locations for exported cache. ## Multiple caches BuildKit supports multiple cache exporters, allowing you to push cache to more than one destination. You can also import from as many remote caches as you'd like. For example, a common pattern is to use the cache of both the current branch and the main branch. The following example shows importing cache from multiple locations using the registry cache backend: ```console $ docker buildx build --push -t <registry>/<image> \ --cache-to type=registry,ref=<registry>/<cache-image>:<branch> \ --cache-from type=registry,ref=<registry>/<cache-image>:<branch> \ --cache-from type=registry,ref=<registry>/<cache-image>:main . ``` ## Configuration options This section describes some configuration options available when generating cache exports. The options described here are common for at least two or more backend types. Additionally, the different backend types support specific parameters as well. See the detailed page about each backend type for more information about which configuration parameters apply. The common parameters described here are: - [Cache mode](#cache-mode) - [Cache compression](#cache-compression) - [OCI media type](#oci-media-types) ### Cache mode When generating a cache output, the `--cache-to` argument accepts a `mode` option for defining which layers to include in the exported cache. This is supported by all cache backends except for the `inline` cache. Mode can be set to either of two options: `mode=min` or `mode=max`. For example, to build the cache with `mode=max` with the registry backend: ```console $ docker buildx build --push -t <registry>/<image> \ --cache-to type=registry,ref=<registry>/<cache-image>,mode=max \ --cache-from type=registry,ref=<registry>/<cache-image> . ``` This option is only set when exporting a cache, using `--cache-to`. When

BuildKit supports multiple cache exporters and importers. A common pattern is to use caches from multiple branches. When generating cache exports, the `--cache-to` argument can be configured with options for cache mode (`min` or `max`), compression, and OCI media types. Cache mode determines which layers to include in the exported cache, and is set only when exporting a cache using `--cache-to`.