dotcloud/docker — pull request #1271 by vieux (2013-07-23 15:21:28+00:00)
Title: Change dockercfg to json and support multiple auth remote

Related to #1246

.dockercfg is now in JSON and can store multiple auth remote, for exemple:

$>cat ~/.dockercfg
auth = xxxxxxxxxxxxxxxxxxxx
email = victor@dotcloud.com

Becomes:

cat ~/.dockercfg
{
"https://index.docker.io/v1/":
{
"auth":"xxxxxxxxxxxxxxxxxxxx",
"email":"victor@dotcloud.com"
}
}

I drop support for API version < 1.2 (auth stored in the server) as the format of the .dockercfg as changed.
This is a **first step** to improve `docker login`, for now, docker login and docker push will always use the index url as key, but pushing to another auth will be easier. (we could for example add a parameter to `docker login`, like `docker login "https://index.docker.io/v1/"` or `docker login "http://localhost:5000"`

/cc @samalba