Rethink login to registry

[andriisoldatenko]

i have created test:

func TestLoginFailed(t *testing.T) {
	err := ExecLogin("https://quay.io/v1", "", "")
	if err == nil {
		t.Error(err)
	}
}

and results we can check in OSX:

cat ~/.docker/config.json
{
	"auths": {
		"https://quay.io/v1": {},
		"quay.io": {}
	},
	"HttpHeaders": {
		"User-Agent": "Docker-Client/18.09.2 (darwin)"
	},
	"credsStore": "osxkeychain"
}%

and windows:

{
	"auths": {
		"https://index.docker.io/v1/": {},
		"quay.io": {},
		"registry.datarouter.ai": {}
	},
	"HttpHeaders": {
		"User-Agent": "Docker-Client/18.09.2 (windows)"
	},
	"credsStore": "wincred"
}

[andriisoldatenko]

@schnie also i need something like this to start writing some tests
https://stackoverflow.com/questions/46366271/using-dind-on-drone-io can you enable it?

[schnie]

@andriisoldatenko looks good! You should be able to do something similar to what we do here: https://github.com/astronomer/astronomer/blob/master/.drone.yml#L45. Would that work? The drone settings should allow for it.

[andriisoldatenko]

@schnie nice catch thanks! fixed.