Right now when we find a v1.Tarball in the local disk cache, we
recompute the digest. This is very expensive and redundant, because
we store tarballs by their digest and use that as a key to look them up.
* comments
* initial commit for persisent volume caching
* cache warmer works
* general cleanup
* adding some debugging
* adding missing files
* Fixing up cache retrieval and cleanup
* fix tests
* removing auth since we only cache public images
* simplifying the caching logic
* fixing logic
* adding volume cache to integration tests. remove auth from cache warmer image.
* add building warmer to integration-test
* move sample yaml files to examples dir
* small test fix
To add layer caching to kaniko, I added two flags: --cache and
--use-cache.
If --use-cache is set, then the cache will be used, and if --cache is
specified then that repo will be used to store cached layers. If --cache
isn't set, a cache will be inferred from the destination provided.
Currently, caching only works for RUN commands. Before executing the
command, kaniko checks if the cached layer exists. If it does, it pulls
it and extracts it. It then adds those files to the snapshotter and
append a layer to the config history. If the cached layer does not exist, kaniko executes the command and
pushes the newly created layer to the cache.
All cached layers are tagged with a stable key, which is built based off
of:
1. The base image digest
2. The current state of the filesystem
3. The current command being run
4. The current config file (to account for metadata changes)
I also added two integration tests to make sure caching works
1. Dockerfile_test_cache runs 'date', which should be exactly the same
the second time the image is built
2. Dockerfile_test_cache_install makes sure apt-get install can be
reproduced
Fredrik Lönnegren
Daisuke Taniwaki
dlorenc
Sharif Elgamal
Priya Wadhwa