yoink viper back out of code, simplify some config logic

config/config_docker.go

@@ -12,7 +12,6 @@ type dockerNetworkInterfaces struct {
 		Subnet  string `default:"172.18.0.0/16"`
 		Gateway string `default:"172.18.0.1"`
 	}
-
 	V6 struct {
 		Subnet  string `default:"fdba:17c8:6c94::/64"`
 		Gateway string `default:"fdba:17c8:6c94::1011"`
@@ -39,8 +38,8 @@ type DockerNetworkConfiguration struct {
 	Interfaces dockerNetworkInterfaces `yaml:"interfaces"`
 }
 
-// Defines the docker configuration used by the daemon when interacting with
-// containers and networks on the system.
+// DockerConfiguration defines the docker configuration used by the daemon when
+// interacting with containers and networks on the system.
 type DockerConfiguration struct {
 	// Network configuration that should be used when creating a new network
 	// for containers run through the daemon.
@@ -58,23 +57,22 @@ type DockerConfiguration struct {
 	TmpfsSize uint `default:"100" json:"tmpfs_size" yaml:"tmpfs_size"`
 }
 
-// RegistryConfiguration .
+// RegistryConfiguration defines the authentication credentials for a given
+// Docker registry.
 type RegistryConfiguration struct {
 	Username string `yaml:"username"`
 	Password string `yaml:"password"`
 }
 
-// Base64 .
+// Base64 returns the authentication for a given registry as a base64 encoded
+// string value.
 func (c RegistryConfiguration) Base64() (string, error) {
-	authConfig := types.AuthConfig{
+	b, err := json.Marshal(types.AuthConfig{
 		Username: c.Username,
 		Password: c.Password,
-	}
-
-	b, err := json.Marshal(authConfig)
+	})
 	if err != nil {
 		return "", err
 	}
-
 	return base64.URLEncoding.EncodeToString(b), nil
 }