simplify version cmd + add json option (#139)

Signed-off-by: Alex Goodman <alex.goodman@anchore.com>

cmd/version.go

@@ -1,15 +1,17 @@
 package cmd
 
 import (
+	"encoding/json"
 	"fmt"
+	"os"
 
 	v1 "github.com/anchore/grype-db/pkg/db/v1"
 	"github.com/anchore/grype/internal"
 	"github.com/anchore/grype/internal/version"
 	"github.com/spf13/cobra"
 )
 
-var showVerboseVersionInfo bool
+var outputFormat string
 
 var versionCmd = &cobra.Command{
 	Use:   "version",
@@ -18,14 +20,15 @@ var versionCmd = &cobra.Command{
 }
 
 func init() {
-	versionCmd.Flags().BoolVarP(&showVerboseVersionInfo, "verbose", "v", false, "show additional version information")
+	versionCmd.Flags().StringVarP(&outputFormat, "output", "o", "text", "format to show version information (available=[text, json])")
 
 	rootCmd.AddCommand(versionCmd)
 }
 
 func printVersion(_ *cobra.Command, _ []string) {
 	versionInfo := version.FromBuild()
-	if showVerboseVersionInfo {
+	switch outputFormat {
+	case "text":
 		fmt.Println("Application:         ", internal.ApplicationName)
 		fmt.Println("Version:             ", versionInfo.Version)
 		fmt.Println("BuildDate:           ", versionInfo.BuildDate)
@@ -35,7 +38,26 @@ func printVersion(_ *cobra.Command, _ []string) {
 		fmt.Println("GoVersion:           ", versionInfo.GoVersion)
 		fmt.Println("Compiler:            ", versionInfo.Compiler)
 		fmt.Println("Supported DB Schema: ", v1.SchemaVersion)
-	} else {
-		fmt.Printf("%s %s\n", internal.ApplicationName, versionInfo.Version)
+	case "json":
+
+		enc := json.NewEncoder(os.Stdout)
+		enc.SetEscapeHTML(false)
+		enc.SetIndent("", " ")
+		err := enc.Encode(&struct {
+			version.Version
+			Application   string `json:"application"`
+			SchemaVersion int    `json:"supported-db-schema"`
+		}{
+			Version:       versionInfo,
+			Application:   internal.ApplicationName,
+			SchemaVersion: v1.SchemaVersion,
+		})
+		if err != nil {
+			fmt.Printf("failed to show version information: %+v\n", err)
+			os.Exit(1)
+		}
+	default:
+		fmt.Printf("unsupported output format: %s\n", outputFormat)
+		os.Exit(1)
 	}
 }

internal/version/build.go

@@ -14,13 +14,13 @@ var buildDate = valueNotProvided
 var platform = fmt.Sprintf("%s/%s", runtime.GOOS, runtime.GOARCH)
 
 type Version struct {
-	Version      string
-	GitCommit    string
-	GitTreeState string
-	BuildDate    string
-	GoVersion    string
-	Compiler     string
-	Platform     string
+	Version      string `json:"version"`
+	GitCommit    string `json:"git-commit"`
+	GitTreeState string `json:"git-tree-state"`
+	BuildDate    string `json:"build-date"`
+	GoVersion    string `json:"go-version"`
+	Compiler     string `json:"compiler"`
+	Platform     string `json:"platform"`
 }
 
 func FromBuild() Version {