tetra: version cmd default to CLI and add build info

Version commands are usually expected to return quickly and can be used
to see if the CLI is well installed and works, I think it's best to put
the server version behind a flag. We could also adjust the timeout for
this command in order to return quickly.

Signed-off-by: Mahe Tardy <[email protected]>

cmd/tetra/version/version.go

@@ -20,49 +20,55 @@ import (
 
 	"github.com/cilium/tetragon/api/v1/tetragon"
 	"github.com/cilium/tetragon/cmd/tetra/common"
+	"github.com/cilium/tetragon/pkg/logger"
 	"github.com/cilium/tetragon/pkg/version"
 
 	"github.com/spf13/cobra"
-	"github.com/spf13/viper"
 )
 
-func printClientersion() {
-	fmt.Printf("cli version: %s\n", version.Version)
-}
+const examples = `  # Retrieve version from server
+  tetra version --server
 
-func printVersion(res *tetragon.GetVersionResponse, err error) {
-	if err == nil {
-		fmt.Printf("server version: %s\n", res.Version)
-		printClientersion()
-	} else {
-		fmt.Printf("error getting server version: %s\n", err)
-		printClientersion()
-	}
-}
+  # Get build info for the CLI
+  tetra version --build`
+
+var (
+	server bool
+	build  bool
+)
 
 func New() *cobra.Command {
 	cmd := &cobra.Command{
-		Use:   "version",
-		Short: "Print version",
-		Args:  cobra.NoArgs,
+		Use:     "version",
+		Short:   "Print version from CLI and server",
+		Example: examples,
+		Args:    cobra.NoArgs,
 		Run: func(cmd *cobra.Command, args []string) {
-			if viper.GetBool("client") {
-				printClientersion()
-				return
+			fmt.Printf("CLI version: %s\n", version.Version)
+
+			if server {
+				common.CliRunErr(
+					func(ctx context.Context, cli tetragon.FineGuidanceSensorsClient) {
+						res, err := cli.GetVersion(ctx, &tetragon.GetVersionRequest{})
+						if err != nil {
+							logger.GetLogger().WithError(err).Error("error retrieving server version")
+						}
+						fmt.Printf("Server version: %s\n", res.Version)
+					},
+					func(err error) {
+						logger.GetLogger().WithError(err).Error("error retrieving server version")
+					},
+				)
+			}
+
+			if build {
+				info := version.ReadBuildInfo()
+				info.Print()
 			}
-			common.CliRunErr(
-				func(ctx context.Context, cli tetragon.FineGuidanceSensorsClient) {
-					res, err := cli.GetVersion(ctx, &tetragon.GetVersionRequest{})
-					printVersion(res, err)
-				},
-				func(err error) {
-					printVersion(nil, err)
-				},
-			)
 		},
 	}
 	flags := cmd.Flags()
-	flags.Bool("client", false, "Only print client version without attempting to connect to server")
-	viper.BindPFlags(flags)
+	flags.BoolVarP(&server, "server", "s", false, "Connect and retrieve version from the server")
+	flags.BoolVarP(&build, "build", "b", false, "Show CLI build information")
 	return cmd
 }

pkg/version/version.go

@@ -3,4 +3,61 @@
 
 package version
 
+import (
+	"fmt"
+	"runtime/debug"
+)
+
 var Version string
+
+type BuildInfo struct {
+	GoVersion string
+	Commit    string
+	Time      string
+	Modified  string
+}
+
+func ReadBuildInfo() *BuildInfo {
+	info := &BuildInfo{}
+	buildInfo, ok := debug.ReadBuildInfo()
+	if ok {
+		info.GoVersion = buildInfo.GoVersion
+		// unfortunately, it's not a Go map
+		for _, s := range buildInfo.Settings {
+			if s.Key == "vcs.revision" {
+				info.Commit = s.Value
+				continue
+			}
+			if s.Key == "vcs.time" {
+				info.Time = s.Value
+				continue
+			}
+			if s.Key == "vcs.modified" {
+				info.Modified = s.Value
+				continue
+			}
+		}
+	}
+	return info
+}
+
+func (info BuildInfo) Print() {
+	if info.GoVersion != "" {
+		fmt.Printf("GoVersion: %s\n", info.GoVersion)
+	}
+	if info.Time != "" {
+		fmt.Printf("Date: %s\n", info.Time)
+	}
+	if info.Commit != "" {
+		fmt.Printf("GitCommit: %s\n", info.Commit)
+	}
+	if info.Modified != "" {
+		var state string
+		if info.Modified == "true" {
+			state = "dirty"
+		} else {
+			state = "clean"
+		}
+		fmt.Printf("GitTreeState: %s\n", state)
+	}
+}