From 35f9f85b5defabf01b1cb41d6da8d19063b868ba Mon Sep 17 00:00:00 2001
From: Tiger Kaovilai <tkaovila@redhat.com>
Date: Tue, 12 Nov 2024 16:00:13 -0500
Subject: [PATCH] Add go buildinfo to velero to assist with #8397

Signed-off-by: Tiger Kaovilai <tkaovila@redhat.com>
---
 changelogs/unreleased/8398-kaovilai |  1 +
 go.mod                              |  5 +++++
 pkg/buildinfo/buildinfo.go          | 19 ++++++++++++++++++-
 pkg/cmd/cli/version/version.go      |  1 +
 pkg/cmd/cli/version/version_test.go |  2 +-
 pkg/cmd/server/server.go            |  2 +-
 6 files changed, 27 insertions(+), 3 deletions(-)
 create mode 100644 changelogs/unreleased/8398-kaovilai

diff --git a/changelogs/unreleased/8398-kaovilai b/changelogs/unreleased/8398-kaovilai
new file mode 100644
index 0000000000..ff67ec2a03
--- /dev/null
+++ b/changelogs/unreleased/8398-kaovilai
@@ -0,0 +1 @@
+Add go buildinfo to velero to identify toolchain used to build velero
diff --git a/go.mod b/go.mod
index a72b539c59..4253037f1d 100644
--- a/go.mod
+++ b/go.mod
@@ -1,5 +1,10 @@
 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
 go 1.22.0
 
 require (
diff --git a/pkg/buildinfo/buildinfo.go b/pkg/buildinfo/buildinfo.go
index b0533d0dbf..acbe0e75df 100644
--- a/pkg/buildinfo/buildinfo.go
+++ b/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
+}
diff --git a/pkg/cmd/cli/version/version.go b/pkg/cmd/cli/version/version.go
index f8d2611161..a208bcc1d9 100644
--- a/pkg/cmd/cli/version/version.go
+++ b/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
diff --git a/pkg/cmd/cli/version/version_test.go b/pkg/cmd/cli/version/version_test.go
index 355626802f..939102e235 100644
--- a/pkg/cmd/cli/version/version_test.go
+++ b/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
diff --git a/pkg/cmd/server/server.go b/pkg/cmd/server/server.go
index 776502f093..33fa0b3e78 100644
--- a/pkg/cmd/server/server.go
+++ b/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 {