feat: use viper standard for command inputs

cmd/local/local.go

@@ -61,11 +61,7 @@ func NewCommand() *cobra.Command {
 	localCmd.Flags().StringVar(&metaphorBranch, "metaphor-branch", "main", "metaphro application branch")
 	localCmd.Flags().StringVar(&gitOpsBranch, "gitops-branch", "main", "version/branch used on git clone - former: version-gitops flag")
 	localCmd.Flags().StringVar(&gitOpsRepo, "gitops-repo", "gitops", "")
-
 	localCmd.Flags().BoolVar(&enableConsole, "enable-console", true, "If hand-off screen will be presented on a browser UI")
-	// todo:
-	//initCmd.Flags().StringP("config", "c", "", "File to be imported to bootstrap configs")
-	//viper.BindPFlag("config.file", currentCommand.Flags().Lookup("config-load"))
 
 	return localCmd
 }

cmd/local/prerun.go

@@ -80,7 +80,7 @@ func validateLocal(cmd *cobra.Command, args []string) error {
 
 	// convert available disk size to GB format
 	availableDiskSize := float64(free) / humanize.GByte
-	if availableDiskSize > pkg.MinimumAvailableDiskSize {
+	if availableDiskSize < pkg.MinimumAvailableDiskSize {
 		return fmt.Errorf(
 			"there is not enough space to proceed with the installation, a minimum of %d GB is required to proceed",
 			pkg.MinimumAvailableDiskSize,

cmd/root.go

@@ -3,6 +3,7 @@ package cmd
 import (
 	"fmt"
 	"github.com/kubefirst/kubefirst/cmd/local"
+	"github.com/kubefirst/kubefirst/configs"
 	"os"
 
 	"github.com/kubefirst/kubefirst/internal/progressPrinter"
@@ -16,8 +17,11 @@ var rootCmd = &cobra.Command{
 	Long: `kubefirst management cluster installer provisions an
 	open source application delivery platform in under an hour. 
 	checkout the docs at docs.kubefirst.io.`,
+	PersistentPreRunE: func(cmd *cobra.Command, args []string) error {
+		// wire viper config for flags for all commands
+		return configs.InitializeViperConfig(cmd)
+	},
 	Run: func(cmd *cobra.Command, args []string) {
-		//log.Println(viper.Get("name"))
 		fmt.Println("To learn more about kubefirst, run:")
 		fmt.Println("  kubefirst help")
 	},
@@ -38,11 +42,5 @@ func Execute() {
 
 func init() {
 	cobra.OnInitialize()
-
-	// Cobra also supports local flags, which will only run, when this action is called directly.
-	rootCmd.Flags().BoolP("toggle", "t", false, "Help message for toggle")
-
-	// todo: temporary, move it into CLI tree
 	rootCmd.AddCommand(local.NewCommand())
-
 }

configs/viperConfig.go

@@ -0,0 +1,99 @@
+package configs
+
+// code from: https://github.com/carolynvs/stingoftheviper
+
+import (
+	"fmt"
+	"github.com/spf13/cobra"
+	"github.com/spf13/pflag"
+	"github.com/spf13/viper"
+	"strings"
+)
+
+// it follows Viper precedence:
+// 1. explicit call to Set
+// 2. flag
+// 3. env
+// 4. config
+// 5. key/value store
+// 6. default
+
+// the input file that is able to provide is called kubefirst.yaml, and should be at the root folder, where the user has
+// it's Kubefirst binary. Following the flag name convention is enough to have a Kubefirst config file.
+
+// FLAGS VARIABLE
+// example loading values from flags:
+// go run . command-name --admin-email user@example.com
+
+// ENVIRONMENT VARIABLE
+// example loading environment variables:
+// export KUBEFIRST_CLOUD=k3d
+// command line commands loads the values from the environment variable and override the command flag.
+
+// YAML
+// example of a YAML Kubefirst file:
+// admin-email: user@example.com
+// cloud: k3d
+// command line commands loads the value from the kubefirst.yaml and override the command flags.
+
+const (
+	// The name of our config file, without the file extension because viper supports many different config file languages.
+	defaultConfigFilename = "kubefirst"
+
+	// The environment variable prefix of all environment variables bound to our command line flags.
+	// For example, --number is bound to STING_NUMBER.
+	envPrefix = "KUBEFIRST"
+)
+
+func InitializeViperConfig(cmd *cobra.Command) error {
+	v := viper.New()
+
+	// Set the base name of the config file, without the file extension.
+	v.SetConfigName(defaultConfigFilename)
+	v.SetConfigType("yaml")
+
+	// Set as many paths as you like where viper should look for the
+	// config file. We are only looking in the current working directory.
+	v.AddConfigPath(".")
+
+	// Attempt to read the config file, gracefully ignoring errors
+	// caused by a config file not being found. Return an error
+	// if we cannot parse the config file.
+	if err := v.ReadInConfig(); err != nil {
+		// It's okay if there isn't a config file
+		if _, ok := err.(viper.ConfigFileNotFoundError); !ok {
+			return err
+		}
+	}
+
+	// When we bind flags to environment variables expect that the
+	// environment variables are prefixed, e.g. a flag like --number
+	// binds to an environment variable STING_NUMBER. This helps
+	// avoid conflicts.
+	v.SetEnvPrefix(envPrefix)
+
+	// Bind to environment variables
+	// Works great for simple config names, but needs help for names
+	// like --favorite-color which we fix in the bindFlags function
+	v.AutomaticEnv()
+
+	// Bind the current command's flags to viper
+	bindFlags(cmd, v)
+
+	return nil
+}
+
+// Bind each cobra flag to its associated viper configuration (config file and environment variable)
+func bindFlags(cmd *cobra.Command, v *viper.Viper) {
+	cmd.Flags().VisitAll(func(f *pflag.Flag) {
+		// Environment variables can't have dashes in them, so bind them to their equivalent
+		// keys with underscores, e.g. --favorite-color to STING_FAVORITE_COLOR
+		v.SetEnvKeyReplacer(strings.NewReplacer("-", "_"))
+
+		// Apply the viper config value to the flag when the flag is not set and viper has a value
+		if !f.Changed && v.IsSet(f.Name) {
+			val := v.Get(f.Name)
+			cmd.Flags().Set(f.Name, fmt.Sprintf("%v", val))
+		}
+	})
+}