add version subcommand

cmd/root.go

@@ -14,7 +14,8 @@ var (
 	validKeyFormat     = regexp.MustCompile(`^[A-Za-z0-9-_]+$`)
 	validServiceFormat = regexp.MustCompile(`^[A-Za-z0-9-_]+$`)
 
-	numRetries int
+	numRetries     int
+	chamberVersion string
 )
 
 const (
@@ -27,9 +28,9 @@ const (
 
 // RootCmd represents the base command when called without any subcommands
 var RootCmd = &cobra.Command{
-	Use:           "chamber",
-	Short:         "CLI for storing secrets",
-	SilenceUsage:  true,
+	Use:          "chamber",
+	Short:        "CLI for storing secrets",
+	SilenceUsage: true,
 }
 
 func init() {
@@ -38,7 +39,8 @@ func init() {
 
 // Execute adds all child commands to the root command sets flags appropriately.
 // This is called by main.main(). It only needs to happen once to the rootCmd.
-func Execute() {
+func Execute(vers string) {
+	chamberVersion = vers
 	if cmd, err := RootCmd.ExecuteC(); err != nil {
 		if strings.Contains(err.Error(), "arg(s)") || strings.Contains(err.Error(), "usage") {
 			cmd.Usage()

cmd/version.go

@@ -0,0 +1,24 @@
+package cmd
+
+import (
+	"fmt"
+	"os"
+
+	"github.com/spf13/cobra"
+)
+
+// versionCmd represents the version command
+var versionCmd = &cobra.Command{
+	Use:   "version",
+	Short: "print version",
+	RunE:  versionRun,
+}
+
+func init() {
+	RootCmd.AddCommand(versionCmd)
+}
+
+func versionRun(cmd *cobra.Command, args []string) error {
+	fmt.Fprintf(os.Stdout, "chamber %s\n", chamberVersion)
+	return nil
+}

main.go

@@ -2,6 +2,11 @@ package main
 
 import "github.com/segmentio/chamber/cmd"
 
+var (
+	// This is updated by linker flags during build
+	Version = "dev"
+)
+
 func main() {
-	cmd.Execute()
+	cmd.Execute(Version)
 }