Implement sub-command "version"

Makefile

@@ -1,8 +1,11 @@
 .PHONY: staticcheck dependency clean build release all
 
 PKGS       := $(shell go list ./...)
+REPO       := github.com/guessi/cloudtrail-cli
+BUILDTIME  := $(shell date -u +"%Y-%m-%dT%H:%M:%SZ")
 GITVERSION := $(shell git describe --tags --abbrev=8)
-LDFLAGS    := -s -w
+GOVERSION  := $(shell go version | cut -d' ' -f3)
+LDFLAGS    := -s -w -X "$(REPO)/pkg/constants.GitVersion=$(GITVERSION)" -X "$(REPO)/pkg/constants.GoVersion=$(GOVERSION)" -X "$(REPO)/pkg/constants.BuildTime=$(BUILDTIME)"
 
 default: build
 

main.go

@@ -1,23 +1,45 @@
 package main
 
 import (
+	"fmt"
 	"os"
+	"regexp"
 
 	"github.com/guessi/cloudtrail-cli/cmd"
 	"github.com/guessi/cloudtrail-cli/pkg/constants"
 	"github.com/urfave/cli/v2"
 )
 
+func showVersion() {
+	r, _ := regexp.Compile(`v[0-9]\.[0-9]+\.[0-9]+`)
+	versionInfo := r.FindString(constants.GitVersion)
+	fmt.Println("cloudtrail-cli", versionInfo)
+	fmt.Println(" Git Commit:", constants.GitVersion)
+	fmt.Println(" Build with:", constants.GoVersion)
+	fmt.Println(" Build time:", constants.BuildTime)
+}
+
 func main() {
 	app := &cli.App{
 		Name:    constants.NAME,
 		Usage:   constants.USAGE,
-		Version: constants.VERSION,
+		Version: constants.GitVersion,
 		Flags:   cmd.Flags,
 		Action: func(c *cli.Context) error {
 			cmd.Wrapper(c)
 			return nil
 		},
+		Commands: []*cli.Command{
+			{
+				Name:    "version",
+				Aliases: []string{"v"},
+				Usage:   "Print version number",
+				Action: func(cCtx *cli.Context) error {
+					showVersion()
+					return nil
+				},
+			},
+		},
 	}
 
 	err := app.Run(os.Args)

pkg/constants/constants.go

@@ -1,7 +1,12 @@
 package constants
 
 const (
-	NAME    string = "cloudtrail-cli"
-	USAGE   string = "Blazing fast single purpose cli for CloudTrail log filtering"
-	VERSION string = "1.0.9"
+	NAME  string = "cloudtrail-cli"
+	USAGE string = "Blazing fast single purpose cli for CloudTrail log filtering"
+)
+
+var (
+	GitVersion string
+	GoVersion  string
+	BuildTime  string
 )