No support for hostnames with a hypen

[StephanePaulus]

I am trying this credential helper with a docker repo like: mr-artifactory.data.internal
I think the issue is because hypens are not allowed in env variables.

So when I do EXPORT DOCKER_mr_artifactory_data_internal_USR, it cannot find the credentials as it doesn't match
mr.artifactory.data.internal

[StephanePaulus]

After looking at the code:

func getEnvCredentials(hostname string) (username, password string, found bool) {
	labels := strings.Split(hostname, ".")

	for i := 0; i <= len(labels); i++ {
		envUsername, envPassword := getEnvVariables(labels, i)

		if username, found = os.LookupEnv(envUsername); found {
			if password, found = os.LookupEnv(envPassword); found {
				break
			}
		}
	}
	return
}

The hostname is just split based on the . char. So in the case of the host also having a - it will try to find env variables with the - in it. In my case DOCKER_mr-artifactory_USR, which is not valid. I don't want to use the catch all `DOCKER__USR' variable as this limit my choices.

[isometry]

@StephanePaulus - thanks for the bug report! What do you think would be the cleanest label transformation here? s/-/_/g (i.e. DOCKER_mr_artifactory_data_internal_USR) or s/-//g (i.e. DOCKER_mrartifactory_data_internal_USR)? I lean toward the first.

To unblock you, the workaround would be DOCKER_data_internal_USR to scope to all Docker registries within the data.internal zone.

[StephanePaulus]

@isometry I would also think the first 1 makes the most sense.