http: avoid possible digest mismatch error #5343
Merged
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
There is a possibility to get a digest mismatch error if the metadata for previous download does not point to a valid reference anymore.
To mitigate this, check that ref that etag points to is still valid before using it.
Additionally
.cacheKey
property was not previously set in the cases where the old reference was reused. This caused a case where even if the download needed to be performed again, it always failed validation, even if the digest had not actually changed since the previous download.There is still a small possibility that gc/prune request will delete the downloaded record in between cachemap and exec call and that the contents changes in the server at that exact time. To fix that case, we would need to modify cachemap so that it can keep hold of references until build is complete.
fixes #5020
cc @dnephin