feat: add version command (#26)

Makefile

@@ -1,13 +1,19 @@
 GO := go
 BIN_DIR := bin
 BIN := $(BIN_DIR)/pmg
+SHELL := /bin/bash
+GITCOMMIT := $(shell git rev-parse HEAD)
+VERSION := "$(shell git describe --tags --abbrev=0)-$(shell git rev-parse --short HEAD)"
+
+GO_CFLAGS=-X 'github.com/safedep/pmg/cmd/version.commit=$(GITCOMMIT)' -X 'github.com/safedep/pmg/cmd/version.version=$(VERSION)'
+GO_LDFLAGS=-ldflags "-w $(GO_CFLAGS)"
 
 .PHONY: all
 
 all: pmg
 
 pmg: create_bin
-	$(GO) build -o $(BIN) main.go
+	$(GO) build ${GO_LDFLAGS} -o $(BIN) main.go
 
 create_bin:
 	mkdir -p $(BIN_DIR)

cmd/version/version.go

@@ -0,0 +1,34 @@
+package version
+
+import (
+	"fmt"
+	"os"
+	runtimeDebug "runtime/debug"
+
+	"github.com/spf13/cobra"
+)
+
+var (
+	version string
+	commit  string
+)
+
+func init() {
+	if version == "" {
+		buildInfo, _ := runtimeDebug.ReadBuildInfo()
+		version = buildInfo.Main.Version
+	}
+}
+
+func NewVersionCommand() *cobra.Command {
+	return &cobra.Command{
+		Use:   "version",
+		Short: "Show version and build information",
+		RunE: func(cmd *cobra.Command, args []string) error {
+			fmt.Fprintf(os.Stdout, "Version: %s\n", version)
+			fmt.Fprintf(os.Stdout, "CommitSHA: %s\n", commit)
+
+			return nil
+		},
+	}
+}

main.go

@@ -6,6 +6,7 @@ import (
 
 	"github.com/safedep/dry/log"
 	"github.com/safedep/pmg/cmd/npm"
+	"github.com/safedep/pmg/cmd/version"
 	"github.com/safedep/pmg/config"
 	"github.com/safedep/pmg/internal/ui"
 	"github.com/spf13/cobra"
@@ -76,6 +77,7 @@ func main() {
 
 	cmd.AddCommand(npm.NewNpmCommand())
 	cmd.AddCommand(npm.NewPnpmCommand())
+	cmd.AddCommand(version.NewVersionCommand())
 
 	if err := cmd.Execute(); err != nil {
 		os.Exit(1)