load config values from viper if present in config (#468)

* init config flags in root cmd's PersistentPreRunE

* change Cfg.LookupPlugins to pointer to bool

* simplified logic in setting initial config flags from viper config

pkg/kn/commands/plugin/list.go

@@ -58,12 +58,11 @@ Available plugins are those that are:
 
 // List plugins by looking up in plugin directory and path
 func listPlugins(cmd *cobra.Command, flags pluginListFlags) error {
-
 	pluginPath, err := homedir.Expand(commands.Cfg.PluginsDir)
 	if err != nil {
 		return err
 	}
-	if commands.Cfg.LookupPlugins {
+	if *commands.Cfg.LookupPlugins {
 		pluginPath = pluginPath + string(os.PathListSeparator) + os.Getenv("PATH")
 	}
 
@@ -74,12 +73,12 @@ func listPlugins(cmd *cobra.Command, flags pluginListFlags) error {
 	if flags.verbose {
 		fmt.Fprintf(out, "The following plugins are available, using options:\n")
 		fmt.Fprintf(out, "  - plugins dir: '%s'%s\n", commands.Cfg.PluginsDir, extraLabelIfPathNotExists(pluginPath))
-		fmt.Fprintf(out, "  - lookup plugins in $PATH: '%t'\n", commands.Cfg.LookupPlugins)
+		fmt.Fprintf(out, "  - lookup plugins in $PATH: '%t'\n", *commands.Cfg.LookupPlugins)
 	}
 
 	if len(pluginsFound) == 0 {
 		if flags.verbose {
-			fmt.Fprintf(out, "No plugins found in path %s.\n", pluginPath)
+			fmt.Fprintf(out, "No plugins found in path '%s'.\n", pluginPath)
 		} else {
 			fmt.Fprintln(out, "No plugins found.")
 		}

pkg/kn/commands/plugin/plugin.go

@@ -41,7 +41,7 @@ Please refer to the documentation and examples for more information about how wr
 // AddPluginFlags plugins-dir and lookup-plugins to cmd
 func AddPluginFlags(cmd *cobra.Command) {
 	cmd.Flags().StringVar(&commands.Cfg.PluginsDir, "plugins-dir", "~/.kn/plugins", "kn plugins directory")
-	cmd.Flags().BoolVar(&commands.Cfg.LookupPlugins, "lookup-plugins", false, "look for kn plugins in $PATH")
+	cmd.Flags().BoolVar(commands.Cfg.LookupPlugins, "lookup-plugins", false, "look for kn plugins in $PATH")
 }
 
 // BindPluginsFlagToViper bind and set default with viper for plugins flags

pkg/kn/commands/testing_helper.go

@@ -179,7 +179,7 @@ Eventing: Manage event subscriptions and channels. Connect up event sources.`,
 	rootCmd.PersistentFlags().StringVar(&params.KubeCfgPath, "kubeconfig", "", "kubectl config file (default is $HOME/.kube/config)")
 
 	rootCmd.Flags().StringVar(&Cfg.PluginsDir, "plugins-dir", "~/.kn/plugins", "kn plugins directory")
-	rootCmd.Flags().BoolVar(&Cfg.LookupPlugins, "lookup-plugins", false, "look for kn plugins in $PATH")
+	rootCmd.Flags().BoolVar(Cfg.LookupPlugins, "lookup-plugins", false, "look for kn plugins in $PATH")
 
 	viper.BindPFlag("plugins-dir", rootCmd.Flags().Lookup("plugins-dir"))
 	viper.BindPFlag("lookup-plugins", rootCmd.Flags().Lookup("lookup-plugins"))

pkg/kn/commands/types.go

@@ -38,12 +38,15 @@ import (
 var CfgFile string
 
 // Cfg is Kn's configuration values
-var Cfg Config
+var Cfg Config = Config{
+	PluginsDir:    "",
+	LookupPlugins: newBoolP(false),
+}
 
 // Config contains the variables for the Kn config
 type Config struct {
 	PluginsDir    string
-	LookupPlugins bool
+	LookupPlugins *bool
 }
 
 // KnParams for creating commands. Useful for inserting mocks for testing.
@@ -169,3 +172,11 @@ func (params *KnParams) GetClientConfig() (clientcmd.ClientConfig, error) {
 	}
 	return nil, fmt.Errorf("Config file '%s' can not be found", params.KubeCfgPath)
 }
+
+// Private
+
+// Returns a pointer to bool, hard to do better in Golang
+func newBoolP(b bool) *bool {
+	aBool := b
+	return &aBool
+}

pkg/kn/core/root.go

@@ -122,6 +122,7 @@ func NewKnCommand(params ...commands.KnParams) *cobra.Command {
 		SilenceErrors: true,
 
 		PersistentPreRunE: func(cmd *cobra.Command, args []string) error {
+			initConfigFlags()
 			return flags.ReconcileBoolFlags(cmd.Flags())
 		},
 	}
@@ -217,6 +218,17 @@ func initConfig() {
 	}
 }
 
+func initConfigFlags() {
+	if viper.IsSet("plugins-dir") {
+		commands.Cfg.PluginsDir = viper.GetString("plugins-dir")
+	}
+
+	// Always set the Cfg.LookupPlugins from viper value since default is false both ways
+	var aBool bool
+	aBool = viper.GetBool("lookup-plugins")
+	commands.Cfg.LookupPlugins = &aBool
+}
+
 func extractKnPluginFlags(args []string) (string, bool, error) {
 	pluginsDir := "~/.kn/plugins"
 	lookupPluginsInPath := false