Use debug.ReadBuildInfo for retrieving plugin version

go.mod

@@ -1,6 +1,6 @@
 module github.com/grpc-ecosystem/grpc-gateway/v2
 
-go 1.17
+go 1.18
 
 require (
 	github.com/antihax/optional v1.0.0

protoc-gen-grpc-gateway/main.go

@@ -13,6 +13,7 @@ import (
 	"flag"
 	"fmt"
 	"os"
+	"runtime/debug"
 	"strings"
 
 	"github.com/golang/glog"
@@ -44,12 +45,20 @@ var (
 	date    = "unknown"
 )
 
+func buildVersion() string {
+	v, ok := debug.ReadBuildInfo()
+	if !ok {
+		return version
+	}
+	return v.Main.Version
+}
+
 func main() {
 	flag.Parse()
 	defer glog.Flush()
 
 	if *versionFlag {
-		fmt.Printf("Version %v, commit %v, built at %v\n", version, commit, date)
+		fmt.Printf("Version %v, commit %v, built at %v\n", buildVersion(), commit, date)
 		os.Exit(0)
 	}
 

protoc-gen-openapiv2/main.go

@@ -4,6 +4,7 @@ import (
 	"flag"
 	"fmt"
 	"os"
+	"runtime/debug"
 	"strings"
 
 	"github.com/golang/glog"
@@ -51,12 +52,20 @@ var (
 	date    = "unknown"
 )
 
+func buildVersion() string {
+	v, ok := debug.ReadBuildInfo()
+	if !ok {
+		return version
+	}
+	return v.Main.Version
+}
+
 func main() {
 	flag.Parse()
 	defer glog.Flush()
 
 	if *versionFlag {
-		fmt.Printf("Version %v, commit %v, built at %v\n", version, commit, date)
+		fmt.Printf("Version %v, commit %v, built at %v\n", buildVersion(), commit, date)
 		os.Exit(0)
 	}