Jon Johnson

Just thinking out loud: How much do we trust the builders? If we need to change them to write to disk, we might as well allow them to just self-report...

What if we have the builders do all the pushing, since they have all the context required to do it efficiently (without trying to serialize that context to disk), but...

@vbatts ack, the OCI image layout would work perfectly for a sparsely populated tarball 👍

@awakecoding might make sense to continue your [ETag discussion](https://github.com/opencontainers/image-spec/pull/826#issuecomment-805415911) here.

> For some odd reason, the ETag is the same as the Docker-Content-Digest except that it is within double quotes. I believe this is a requirement from [the RFC](https://tools.ietf.org/html/rfc7232#section-2.3). >...

> 1. Can we also clarify whether ETAG is bound to the pushed manifest (down conversion of manifest from say manifest list to manifest ) will not effect ETAG? I...

> aren't Etag headers something that can also be inserted by caching proxies? https://tools.ietf.org/html/rfc2616?spm=5176.doc32013.2.3.Aimyd7#section-13.5.2 > A transparent proxy MUST NOT modify any of the following fields in a > request...

> It happens to store a manifest using an oci descriptor, but it's not a blob. Can you clarify what you mean by "but it's not a blob". > This...

@sargun had a comment about registry support for this. Many registries supply ETags today, but it's unclear if they already support conditional requests. One simple idea would be defining an...

> What API would the registry have to add this header for -- all? I would say anywhere that includes an `Etag` header? It would indicate that the client can...