content digest not found

[apostasie]

This is meant to collect more information about the issue known as "content digest not found".

While #3435 (and follow-up for IPFS) did address the most obvious cases, we obviously have more.

Here is the currently know list:

• 3509

• 3510

• 3512

The gist of it appears to be, at this point:

• seems like containerd converter.Convert (calling on imageservice.Create) may return an image with missing content in some circumstances
• seems like any call to content.ReadBlob (specifically as seen inside imgutil) may fail and should be gated by an operation to first force fetch the blob in question

At this point, above is speculative, although it seems consistent with the debugging info in the tickets.

[apostasie]

Note that these bugs are elusive. You have to run the test suite for the affected parts for 50+ times before you hit it.

[apostasie]

Update: this all likely ties into #3516