feat: add version command (open-feature#38)

Signed-off-by: Michael Beemer <beeme1mr@users.noreply.github.com>

Author: beeme1mr

cmd/root.go

@@ -9,6 +9,12 @@ import (
 	"github.com/spf13/cobra"
 )
 
+var (
+	Version string
+	Commit  string
+	Date    string
+)
+
 // rootCmd represents the base command when called without any subcommands
 var rootCmd = &cobra.Command{
 	Use:   "openfeature",
@@ -18,7 +24,10 @@ var rootCmd = &cobra.Command{
 
 // Execute adds all child commands to the root command and sets flags appropriately.
 // This is called by main.main(). It only needs to happen once to the rootCmd.
-func Execute() {
+func Execute(version string, commit string, date string) {
+	Version = version
+	Commit = commit
+	Date = date
 	if err := rootCmd.Execute(); err != nil {
 		fmt.Println(err)
 		os.Exit(1)
@@ -27,4 +36,5 @@ func Execute() {
 
 func init() {
 	rootCmd.AddCommand(generate.Root)
+	rootCmd.AddCommand(versionCmd)
 }

cmd/version.go

@@ -0,0 +1,31 @@
+package cmd
+
+import (
+	"fmt"
+	"runtime/debug"
+
+	"github.com/spf13/cobra"
+)
+
+var versionCmd = &cobra.Command{
+	Use:   "version",
+	Short: "Print the version number of the OpenFeature CLI",
+	Long:  ``,
+	Run: func(cmd *cobra.Command, args []string) {
+		if Version == "dev" {
+			details, ok := debug.ReadBuildInfo()
+			if ok && details.Main.Version != "" && details.Main.Version != "(devel)" {
+				Version = details.Main.Version
+				for _, i := range details.Settings {
+					if i.Key == "vcs.time" {
+						Date = i.Value
+					}
+					if i.Key == "vcs.revision" {
+						Commit = i.Value
+					}
+				}
+			}
+		}
+		fmt.Printf("OpenFeature CLI: %s (%s), built at: %s\n", Version, Commit, Date)
+	},
+}

main.go

@@ -2,6 +2,13 @@ package main
 
 import "codegen/cmd"
 
+var (
+	// Overridden by Go Releaser at build time
+	version    = "dev"
+	commit     = "HEAD"
+	date       = "unknown"
+)
+
 func main() {
-	cmd.Execute()
+	cmd.Execute(version, commit, date)
 }