title: .docker/config.json vs .dockercfg
body: <p>When I do a <code>docker login</code> to a private repository using docker 1.10.1, an entry is created in my <code>~/.docker/config.json</code> file.  Is this file in the same format as what I see being called a <code>.dockercfg</code> file?  Is the <code>config.json</code> file interchangeable with a <code>.dockercfg</code> file?</p>