ERRO[0043] failed to dial gRPC: unable to upgrade to h2c, received 501

Question

When I tried building my Dockerfile with docker build -t myimage1 . today I got this error:

ERRO[0043] failed to dial gRPC: unable to upgrade to h2c, received 501
context canceled

I have successfully built this image before although it was a couple of weeks ago. I am not sure whether Docker has been updated in the meantime.

I found a similar error (although not the same - it is error 0044 while mine is 0043) at ERRO[0044] failed to dial gRPC: cannot connect to the Docker daemon

Answer 1

If you just started Docker daemon, please wait for some time and try again.