Absolutely baffling error message from duffle export

[itowlson]

Tried to export a full bundle (and got around the pull error by putting the invocation image under my Docker ID and logging into Docker Hub). And instead got:

Duffle export failed: Error preparing artifacts: MANIFEST_UNKNOWN: manifest unknown; map[Tag:e69ccbf72607bd1219972c438b322789f257a718]

I don't even know what to report here. The message is completely opaque to me. Sorry. If I can provide any more details then let me know.

[itowlson]

The error does not occur when exporting as manifest-only (with the -t option).

[itowlson]

The mysterious string is not the hash in ~/.duffle/bundles; I'm not sure what it is.

[glyn]

That kind of error occurs when duffle export is attempting to pull the images that the bundle refers to. However, I can't find the string manifest unknown in the relevant code. Are you sure the error message above is exactly that which occurred?

Anyway, the problem would appear to be with an image, so you could try docker pull of the images in the bundle and see if that sheds any light.

[itowlson]

Oho! I did the docker pull for the invocation image and here is what Docker told me:

Error response from daemon: manifest for itowlson/arsebiscuits-cnab:e69ccbf72607bd1219972c438b322789f257a718 not found: manifest unknown: manifest unknown

So there is the source of the mysterious message!

And if I do a docker push, then the docker pull works (saying the image is up to date) and - tada - so does the duffle export.

So this is another symptom of the problem where Duffle tries to pull even when the image is available locally, and errors if the pull fails - but surfaced as a very cryptic error message.

Thanks for the catch @glyn!

[jeremyrickard]

@itowlson does this need to be a separate issue from #828 and the corresponding PR that @glyn has for it?

[itowlson]

Yes, I think @glyn's revised error message will address this.