docker login - error storing credentials - write permissions error

I am running a docker login command as a part of the Bamboo build job. The command text is obtained by aws ecr get-login call and executed in a subshell.

This command fails with Error saving credentials: error storing credentials - err: exit status 1, out: write permissions error when ran as a part of the Bamboo build, but the exact same command ran in the Terminal on the Mac that is the build agent, it succeeds.

Using Terminal:

aws ecr get-login succeeds and returns the docker login command text
docker login -u ... -p ... -e none ... succeeds and logs in
There is a record for the ECR URL in KeyChain
There is an entry in ~/.docker/config.json

Using Bamboo:

aws ecr get-login succeeds and returns the docker login command text
docker login -u ... -p ... -e none ... fails with the error above
KeyChain record being made available to all applications makes no difference'
chmod 777 ~/.docker/config.json makes no difference

Both the Bamboo build and the Terminal session happen under the same user - builduser. whoami is the same for both. stat ~/.docker/config.json is the same for both - writable for both.

Can you think of further ways of discovering the differences between the context Bamboo runs the build in and I do in the terminal? The error above, verbatim, related to docker login is nowhere to be found online.

Solution

I had to remove my existing ~/.docker/config.json file. It would not overwrite or modify the one that I had.