docker build giving unauthorized: authentication required

My docker version is

Docker version 1.12.2-cs2-ws-beta, build 050b611

I am trying to build the image using command

docker build -t iis-dockerfile .

The DockerFile content is

FROM microsoft/iss
RUN echo "Hello World - Dockerfile" > C:\inetpub\wwwroot\index.html

config.json is

{
    "auths": {
        "https://index.docker.io/v1/": {
            "auth": <somekey>
        }
    }
}

On running docker build, it gives error

Sending build context to Docker daemon 2.048 kB
Step 1/2 : FROM microsoft/iss
unauthorized: authentication required

I have already done docker login. That's how config.json is created. I am new to containers and following the get started tutorial https://blogs.msdn.microsoft.com/allthingscontainer/2016/09/15/windows-containers-getting-started-a-step-by-step-guide/. Any idea how can I work around this.

Also I figured out that docker pull is working for me. While this also required authentication

Solution

Just an observation. Make sure your docker file has correct base image name. Are you sure you want FROM microsoft/iss and not FROM microsoft/iis?

When I tried to create new image with correct base image. It seem to work.

Docker docker build -t test-iid .
Sending build context to Docker daemon 344.9 MB
Step 1/2 : FROM microsoft/iis
latest: Pulling from microsoft/iis
3889bb8d808b: Downloading
3430754e4d17: Downloading
7aee39cd34f9: Downloading [>                                                  ]   540 kB/122.7 MB
5b8e6b632025: Download complete
e067d71858d2: Download complete