Making minikube start flags configurable by Viper config

This allows most flags for the minikube start command to be
configurable by viper as well.  If a flag is present, it will take
precedence over the value supplied in viper.

Viper doesn't handle string slices correctly (see
spf13/viper#200) so the string slices that we
pass in as flags such as docker-env and insecure-registry are still only
handled by flags

Delete custom flag for human readable disk size

Since the value can now be passed in multiple ways (environment
variable, flag, or config file), moving the conversion out of the flag
and straight into cmd/minikube/cmd/start.go

This changes the helptext for gendocs

cmd/minikube/cmd/start.go

@@ -27,24 +27,28 @@ import (
 	"github.com/docker/machine/libmachine/host"
 	"github.com/golang/glog"
 	"github.com/spf13/cobra"
+	"github.com/spf13/viper"
 	cfg "k8s.io/kubernetes/pkg/client/unversioned/clientcmd/api"
 	"k8s.io/minikube/pkg/minikube/cluster"
 	"k8s.io/minikube/pkg/minikube/constants"
 	"k8s.io/minikube/pkg/minikube/kubeconfig"
 	"k8s.io/minikube/pkg/util"
 )
 
+const (
+	isoURL                = "iso-url"
+	memory                = "memory"
+	cpus                  = "cpus"
+	humanReadableDiskSize = "disk-size"
+	vmDriver              = "vm-driver"
+	kubernetesVersion     = "kubernetes-version"
+	hostOnlyCIDR          = "host-only-cidr"
+)
+
 var (
-	minikubeISO       string
-	memory            int
-	cpus              int
-	disk              = newUnitValue(20 * units.GB)
-	vmDriver          string
-	dockerEnv         []string
-	insecureRegistry  []string
-	registryMirror    []string
-	kubernetesVersion string
-	hostOnlyCIDR      string
+	registryMirror   []string
+	dockerEnv        []string
+	insecureRegistry []string
 )
 
 // startCmd represents the start command
@@ -62,18 +66,18 @@ func runStart(cmd *cobra.Command, args []string) {
 	defer api.Close()
 
 	config := cluster.MachineConfig{
-		MinikubeISO:      minikubeISO,
-		Memory:           memory,
-		CPUs:             cpus,
-		DiskSize:         int(*disk / units.MB),
-		VMDriver:         vmDriver,
+		MinikubeISO:      viper.GetString(isoURL),
+		Memory:           viper.GetInt(memory),
+		CPUs:             viper.GetInt(cpus),
+		DiskSize:         calculateDiskSizeInMB(viper.GetString(humanReadableDiskSize)),
+		VMDriver:         viper.GetString(vmDriver),
 		DockerEnv:        dockerEnv,
 		InsecureRegistry: insecureRegistry,
 		RegistryMirror:   registryMirror,
-		HostOnlyCIDR:     hostOnlyCIDR,
+		HostOnlyCIDR:     viper.GetString(hostOnlyCIDR),
 	}
 	kubernetesConfig := cluster.KubernetesConfig{
-		KubernetesVersion: kubernetesVersion,
+		KubernetesVersion: viper.GetString(kubernetesVersion),
 	}
 
 	var host *host.Host
@@ -124,6 +128,14 @@ func runStart(cmd *cobra.Command, args []string) {
 	fmt.Println("Kubectl is now configured to use the cluster.")
 }
 
+func calculateDiskSizeInMB(humanReadableDiskSize string) int {
+	diskSize, err := units.FromHumanSize(humanReadableDiskSize)
+	if err != nil {
+		glog.Errorf("Invalid disk size: %s", err)
+	}
+	return int(diskSize / units.MB)
+}
+
 // setupKubeconfig reads config from disk, adds the minikube settings, and writes it back.
 // activeContext is true when minikube is the CurrentContext
 // If no CurrentContext is set, the given name will be used.
@@ -167,16 +179,16 @@ func setupKubeconfig(name, server, certAuth, cliCert, cliKey string) error {
 }
 
 func init() {
-	startCmd.Flags().StringVar(&minikubeISO, "iso-url", constants.DefaultIsoUrl, "Location of the minikube iso")
-	startCmd.Flags().StringVar(&vmDriver, "vm-driver", constants.DefaultVMDriver, fmt.Sprintf("VM driver is one of: %v", constants.SupportedVMDrivers))
-	startCmd.Flags().IntVar(&memory, "memory", constants.DefaultMemory, "Amount of RAM allocated to the minikube VM")
-	startCmd.Flags().IntVar(&cpus, "cpus", constants.DefaultCPUS, "Number of CPUs allocated to the minikube VM")
-	diskFlag := startCmd.Flags().VarPF(disk, "disk-size", "", "Disk size allocated to the minikube VM (format: <number>[<unit>], where unit = b, k, m or g)")
-	diskFlag.DefValue = constants.DefaultDiskSize
-	startCmd.Flags().StringVar(&hostOnlyCIDR, "host-only-cidr", "192.168.99.1/24", "The CIDR to be used for the minikube VM (only supported with Virtualbox driver)")
+	startCmd.Flags().String(isoURL, constants.DefaultIsoUrl, "Location of the minikube iso")
+	startCmd.Flags().String(vmDriver, constants.DefaultVMDriver, fmt.Sprintf("VM driver is one of: %v", constants.SupportedVMDrivers))
+	startCmd.Flags().Int(memory, constants.DefaultMemory, "Amount of RAM allocated to the minikube VM")
+	startCmd.Flags().Int(cpus, constants.DefaultCPUS, "Number of CPUs allocated to the minikube VM")
+	startCmd.Flags().String(humanReadableDiskSize, constants.DefaultDiskSize, "Disk size allocated to the minikube VM (format: <number>[<unit>], where unit = b, k, m or g)")
+	startCmd.Flags().String(hostOnlyCIDR, "192.168.99.1/24", "The CIDR to be used for the minikube VM (only supported with Virtualbox driver)")
 	startCmd.Flags().StringSliceVar(&dockerEnv, "docker-env", nil, "Environment variables to pass to the Docker daemon. (format: key=value)")
 	startCmd.Flags().StringSliceVar(&insecureRegistry, "insecure-registry", nil, "Insecure Docker registries to pass to the Docker daemon")
 	startCmd.Flags().StringSliceVar(&registryMirror, "registry-mirror", nil, "Registry mirrors to pass to the Docker daemon")
-	startCmd.Flags().StringVar(&kubernetesVersion, "kubernetes-version", constants.DefaultKubernetesVersion, "The kubernetes version that the minikube VM will (ex: v1.2.3) \n OR a URI which contains a localkube binary (ex: https://storage.googleapis.com/minikube/k8sReleases/v1.3.0/localkube-linux-amd64)")
+	startCmd.Flags().String(kubernetesVersion, constants.DefaultKubernetesVersion, "The kubernetes version that the minikube VM will (ex: v1.2.3) \n OR a URI which contains a localkube binary (ex: https://storage.googleapis.com/minikube/k8sReleases/v1.3.0/localkube-linux-amd64)")
+	viper.BindPFlags(startCmd.Flags())
 	RootCmd.AddCommand(startCmd)
 }

docs/minikube_start.md

@@ -16,7 +16,7 @@ minikube start
 
 ```
       --cpus int                    Number of CPUs allocated to the minikube VM (default 1)
-      --disk-size value             Disk size allocated to the minikube VM (format: <number>[<unit>], where unit = b, k, m or g) (default 20g)
+      --disk-size string            Disk size allocated to the minikube VM (format: <number>[<unit>], where unit = b, k, m or g) (default "20g")
       --docker-env value            Environment variables to pass to the Docker daemon. (format: key=value) (default [])
       --host-only-cidr string       The CIDR to be used for the minikube VM (only supported with Virtualbox driver) (default "192.168.99.1/24")
       --insecure-registry value     Insecure Docker registries to pass to the Docker daemon (default [])