* Extend .dockerignore integration test with copies in later stages
.dockerignore should continue to apply when copying from the build context in later stages, but it currently doesn't
* Replace excluded global with passed along FileContext struct
This new FileContext struct allows much cleaner handling of context specific file exclusions.
The global excluded file state is no longer needed.
Additionally this also fixes the issue where excluded files aren't being applied for build context copies in later build stages.
Previously kaniko would compute the cache key for any copy command by computing
the combined hash of all files in a directory, even if they were listed
as ignored.
With this change, the cache key creation was updated to be aware of ignored
files.
Related issues:
* https://github.com/GoogleContainerTools/kaniko/issues/594
* use the cachekey of the src stage rather than the digest
for COPY --from commands as they are reproducible unlike digests
* track digest to cache keys and stage indexes to digest
* add extra debug logging for troubleshooting cachekey building issues
* convert Sha256 hashes to hex encoded strings rather than plain strings
for easier human reading
* Rework cache key generation a bit.
Cache keys are now based on the previous commands, rather than the previous state
of the filesystem.
* Refactor command interface a bit, only cache the context for commands that use it.
Tinjo Schöni
Tejal Desai
Tejal Desai
Moritz Wanzenböck
Moritz Wanzenböck
Cole Wippern
dlorenc