fix: version command

cmd/version.go

@@ -5,20 +5,70 @@ package cmd
 
 import (
 	"fmt"
+	"runtime/debug"
+	"time"
 
 	"github.com/spf13/cobra"
 )
 
 // GoBlueprintVersion is the version of the cli to be overwritten by goreleaser in the CI run with the version of the release in github
 var GoBlueprintVersion string
 
+// Go Blueprint needs to be built in a specific way to provide useful version information.
+// First we try to get the version from ldflags embedded into GoBlueprintVersion.
+// Then we try to get the version from from the go.mod build info. 
+// If Go Blueprint is installed with a specific version tag or using @latest then that version will be included in bi.Main.Version. 
+// This won't give any version info when running 'go install' with the source code locally.
+// Finally we try to get the version from other embedded VCS info.
+func getGoBlueprintVersion() string {
+	noVersionAvailable := "No version info available for this build, run 'go-blueprint help version' for additional info"
+
+	if len(GoBlueprintVersion) != 0 {
+		return GoBlueprintVersion
+	}
+
+	bi, ok := debug.ReadBuildInfo()
+	if !ok {
+		return noVersionAvailable
+	}
+
+	// If no main version is available, Go defaults it to (devel)
+	if bi.Main.Version != "(devel)" {
+		return bi.Main.Version
+	}
+
+	var vcsRevision string
+	var vcsTime time.Time
+	for _, setting := range bi.Settings {
+		switch setting.Key {
+		case "vcs.revision":
+			vcsRevision = setting.Value
+		case "vcs.time":
+			vcsTime, _ = time.Parse(time.RFC3339, setting.Value)
+		}
+	}
+
+	if vcsRevision != "" {
+		return fmt.Sprintf("%s, (%s)", vcsRevision, vcsTime)
+	}
+
+	return noVersionAvailable
+}
+
 // versionCmd represents the version command
 var versionCmd = &cobra.Command{
 	Use:   "version",
 	Short: "Display application version information.",
-	Long: `The version command provides information about the application's version.
-Use this command to check the current version of the application.`,
+	Long: `
+The version command provides information about the application's version.
+
+Go Blueprint requires version information to be embedded at compile time.
+For detailed version information, Go Blueprint needs to be built as specified in the README installation instructions.
+If Go Blueprint is built within a version control repository and other version info isn't available,
+the revision hash will be used instead.
+	`,
 	Run: func(cmd *cobra.Command, args []string) {
-		fmt.Printf("Go Blueprint CLI version %v\n", GoBlueprintVersion)
+		version := getGoBlueprintVersion()
+		fmt.Printf("Go Blueprint CLI version: %v\n", version)
 	},
 }

contributors.yml

@@ -19,3 +19,5 @@
 - SputNikPlop
 - Yoquec
 - rustafariandev
+- limesten
+- Ujstor