It happened the other day that one user reported that he was unable to pull a docker image from an internal registry. So I tried from my laptop, it looked fine at the first beginning. There were a few downloading processed going on, but it threw the error unknown blob at the end.
So I tried again, then second time it gave another error Error response from daemon: error unmarshalling content: unexpected end of JSON input
Confirmed with the user that the image itself is good, as he tested and pushed the image to the registry a couple days ago. So I started to troubleshoot the registry, and it turned out that partition of where the reverse proxy’s logs were saved was full. I guess thats why the docker pull sessions terminated unexpectedly in the half way – the reverse proxy could not finish the http sessions properly. The docker pull command worked again once I cleared out some free space.
Jackie Chen's IT Workshop 