jpictl: add --version and version command

from `git describe` using go:generate and embed

Signed-off-by: Alejandro Mery <amery@jpi.io>

.gitignore

@@ -1 +1,2 @@
 .tmp
+.version

cmd/jpictl/main.go

@@ -2,6 +2,8 @@
 package main
 
 import (
+	_ "embed"
+
 	"github.com/spf13/cobra"
 )
 
@@ -12,8 +14,9 @@ const (
 
 var (
 	rootCmd = &cobra.Command{
-		Use:   CmdName,
-		Short: "control tool for jpi.cloud",
+		Use:     CmdName,
+		Short:   "control tool for jpi.cloud",
+		Version: version,
 	}
 )
 

cmd/jpictl/version.go

@@ -0,0 +1,31 @@
+package main
+
+import (
+	_ "embed"
+
+	"fmt"
+	"os"
+
+	"github.com/spf13/cobra"
+)
+
+//go:generate sh -c "git describe | tr -d '\r\n' > .version"
+//go:embed .version
+var version string
+
+var versionCmd = &cobra.Command{
+	Use:   "version",
+	Short: "Returns jpictl's version",
+	Args:  cobra.NoArgs,
+	Run: func(_ *cobra.Command, _ []string) {
+		_, _ = fmt.Fprintf(os.Stdout, "%s\n", version)
+	},
+}
+
+func init() {
+	if version == "" {
+		version = "undetermined"
+	}
+
+	rootCmd.AddCommand(versionCmd)
+}