Digest input clarification
Table of contents
- What are the challenges that we are trying to solve?
- What ideas do we have for how to address these challenges?
- How do these ideas break down into…
- Questions?
- What pre-existing work or software can support these ideas?
- Relevant OCI Issues
What are the challenges that we are trying to solve?
The input to digest computations is not clear. For example:
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The ImageID is the hash of the config JSON, but JSON is text and hash algorithms take bytes, and text has multiple serializations to bytes.
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For composite objects like
.tar.gzfiles, sometimes the hash is of the compressed object but sometimes it’s the uncompressed object. -
Why both “Layer DiffID” and “layer digest”? Don’t these serve the same purpose? And if they do have different purposes, the spec should explain the reasoning.
(The Charliecloud team had a lot of trouble debugging this because when a digest computation is wrong, you just get the wrong output with no indication of where the mistake is.)
What ideas do we have for how to address these challenges?
Whenever a digest is introduced by a spec, it should state in the same paragraph as the introduction (or a similar close location) what the input is.
How do these ideas break down into…
Already existing OCI specs?
This suggestion would be relevant to any interactions with digests.