Add go buildinfo to velero to assist with #8397

Signed-off-by: Tiger Kaovilai <tkaovila@redhat.com>

changelogs/unreleased/8398-kaovilai

@@ -0,0 +1 @@
+Add go buildinfo to velero to identify toolchain used to build velero

go.mod

@@ -1,5 +1,11 @@
 module github.com/vmware-tanzu/velero
 
+// Do not pin patch version here. Leave patch at X.Y.0
+// Unset GOTOOLCHAIN to assume GOTOOLCHAIN=local where go cli version in path is used.
+// Use env GOTOOLCHAIN=auto to allow go to decide whichever is newer from go.mod or cli in path.
+// or GOTOOLCHAIN=goX.Y.Z to use a specific toolchain version
+// See: https://go.dev/doc/toolchain#select and https://github.com/vmware-tanzu/velero/issues/8397
+// To bump minor version, run `go get go@X.Y.0 toolchain@none` (ie. `go get go@1.23.0 toolchain@none`)
 go 1.22.0
 
 require (

pkg/buildinfo/buildinfo.go

@@ -19,12 +19,18 @@ limitations under the License.
 // worrying about introducing circular dependencies.
 package buildinfo
 
-import "fmt"
+import (
+	"fmt"
+	"runtime/debug"
+)
 
 var (
 	// Version is the current version of Velero, set by the go linker's -X flag at build time.
 	Version string
 
+	// goVersion is the version of Go that was used to build Velero
+	goBuildInfo *debug.BuildInfo
+
 	// GitSHA is the actual commit that is being built, set by the go linker's -X flag at build time.
 	GitSHA string
 
@@ -44,3 +50,14 @@ func FormattedGitSHA() string {
 	}
 	return GitSHA
 }
+
+func GoVersion() string {
+	if goBuildInfo == nil {
+		var ok bool
+		goBuildInfo, ok = debug.ReadBuildInfo()
+		if !ok {
+			return "cannot read Go BuildInfo"
+		}
+	}
+	return goBuildInfo.GoVersion
+}

pkg/cmd/cli/version/version.go

@@ -69,6 +69,7 @@ func printVersion(w io.Writer, clientOnly bool, kbClient kbclient.Client, server
 	fmt.Fprintln(w, "Client:")
 	fmt.Fprintf(w, "\tVersion: %s\n", buildinfo.Version)
 	fmt.Fprintf(w, "\tGit commit: %s\n", buildinfo.FormattedGitSHA())
+	fmt.Fprintf(w, "\tGo version: %s\n", buildinfo.GoVersion())
 
 	if clientOnly {
 		return

pkg/cmd/cli/version/version_test.go

@@ -49,7 +49,7 @@ func TestPrintVersion(t *testing.T) {
 	buildinfo.GitSHA = "somegitsha"
 	buildinfo.GitTreeState = "dirty"
 
-	clientVersion := fmt.Sprintf("Client:\n\tVersion: %s\n\tGit commit: %s\n", buildinfo.Version, buildinfo.FormattedGitSHA())
+	clientVersion := fmt.Sprintf("Client:\n\tVersion: %s\n\tGit commit: %s\n\tGo version: %s\n", buildinfo.Version, buildinfo.FormattedGitSHA(), buildinfo.GoVersion())
 
 	tests := []struct {
 		name                string

pkg/cmd/server/server.go

@@ -109,7 +109,7 @@ func NewCommand(f client.Factory) *cobra.Command {
 
 			logger.Infof("setting log-level to %s", strings.ToUpper(logLevel.String()))
 
-			logger.Infof("Starting Velero server %s (%s)", buildinfo.Version, buildinfo.FormattedGitSHA())
+			logger.Infof("Starting Velero server %s (%s) go-version: %s", buildinfo.Version, buildinfo.FormattedGitSHA(), buildinfo.GoVersion())
 			if len(features.All()) > 0 {
 				logger.Infof("%d feature flags enabled %s", len(features.All()), features.All())
 			} else {