This changes allow to use kaniko-warmer multiple times without unnecessary docker image downloads.
To check image presence in cache directory I'm using existing cache function that is used by kaniko-executor.
I've considered building separate function to only check image presence, but it will have pretty much the same code.
Questionable decision is to embed CacheOptions type to KanikoOptions and WarmerOptions. Probably this should be resolved by creating interface providing needed options and implement it both mentioned structs. But I've struggled to get a meaningfull name to it.
To replicate previous behaviour of downloading regardless of cache state I've added --force(-f) option.
This changes provides crucial speed-up when downloading images from remote registry is slow.
Closes#722
* 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
Cole Wippern
Sharif Elgamal
v.rul