From 3efe5b572702bce1a7d8971b6c8a39abec6c9344 Mon Sep 17 00:00:00 2001
From: Manan Gupta <manan@planetscale.com>
Date: Fri, 20 Dec 2024 19:48:22 +0530
Subject: [PATCH] test: specify transaction mode as a config parameter

Signed-off-by: Manan Gupta <manan@planetscale.com>
---
 go/test/endtoend/cluster/vtgate_process.go    | 31 +++++++++++++++++++
 .../endtoend/transaction/twopc/main_test.go   |  5 ++-
 go/vt/vtgate/vtgate.go                        |  4 ---
 3 files changed, 35 insertions(+), 5 deletions(-)

diff --git a/go/test/endtoend/cluster/vtgate_process.go b/go/test/endtoend/cluster/vtgate_process.go
index 1290156a1cd..3e8c2635873 100644
--- a/go/test/endtoend/cluster/vtgate_process.go
+++ b/go/test/endtoend/cluster/vtgate_process.go
@@ -57,6 +57,8 @@ type VtgateProcess struct {
 	Directory             string
 	VerifyURL             string
 	VSchemaURL            string
+	ConfigFile            string
+	Config                VTGateConfiguration
 	SysVarSetEnabled      bool
 	PlannerVersion        plancontext.PlannerVersion
 	// Extra Args to be set before starting the vtgate process
@@ -66,6 +68,20 @@ type VtgateProcess struct {
 	exit chan error
 }
 
+type VTGateConfiguration struct {
+	TransactionMode string `json:"transaction_mode,omitempty"`
+}
+
+// ToJSONString will marshal this configuration as JSON
+func (config *VTGateConfiguration) ToJSONString() string {
+	b, _ := json.MarshalIndent(config, "", "\t")
+	return string(b)
+}
+
+func (vtgate *VtgateProcess) RewriteConfiguration() error {
+	return os.WriteFile(vtgate.ConfigFile, []byte(vtgate.Config.ToJSONString()), 0644)
+}
+
 const defaultVtGatePlannerVersion = planbuilder.Gen4
 
 // Setup starts Vtgate process with required arguements
@@ -74,6 +90,7 @@ func (vtgate *VtgateProcess) Setup() (err error) {
 		"--topo_implementation", vtgate.CommonArg.TopoImplementation,
 		"--topo_global_server_address", vtgate.CommonArg.TopoGlobalAddress,
 		"--topo_global_root", vtgate.CommonArg.TopoGlobalRoot,
+		"--config-file", vtgate.ConfigFile,
 		"--log_dir", vtgate.LogDir,
 		"--log_queries_to_file", vtgate.FileToLogQueries,
 		"--port", fmt.Sprintf("%d", vtgate.Port),
@@ -98,6 +115,19 @@ func (vtgate *VtgateProcess) Setup() (err error) {
 			break
 		}
 	}
+	configFile, err := os.Create(vtgate.ConfigFile)
+	if err != nil {
+		log.Errorf("cannot create config file for vtgate: %v", err)
+		return err
+	}
+	_, err = configFile.WriteString(vtgate.Config.ToJSONString())
+	if err != nil {
+		return err
+	}
+	err = configFile.Close()
+	if err != nil {
+		return err
+	}
 	if !msvflag {
 		version, err := mysqlctl.GetVersionString()
 		if err != nil {
@@ -287,6 +317,7 @@ func VtgateProcessInstance(
 		Name:                  "vtgate",
 		Binary:                "vtgate",
 		FileToLogQueries:      path.Join(tmpDirectory, "/vtgate_querylog.txt"),
+		ConfigFile:            path.Join(tmpDirectory, fmt.Sprintf("vtgate-config-%d.json", port)),
 		Directory:             os.Getenv("VTDATAROOT"),
 		ServiceMap:            "grpc-tabletmanager,grpc-throttler,grpc-queryservice,grpc-updatestream,grpc-vtctl,grpc-vtgateservice",
 		LogDir:                tmpDirectory,
diff --git a/go/test/endtoend/transaction/twopc/main_test.go b/go/test/endtoend/transaction/twopc/main_test.go
index 58fe45547a5..37337a62167 100644
--- a/go/test/endtoend/transaction/twopc/main_test.go
+++ b/go/test/endtoend/transaction/twopc/main_test.go
@@ -77,7 +77,6 @@ func TestMain(m *testing.M) {
 
 		// Set extra args for twopc
 		clusterInstance.VtGateExtraArgs = append(clusterInstance.VtGateExtraArgs,
-			"--transaction_mode", "TWOPC",
 			"--grpc_use_effective_callerid",
 		)
 		clusterInstance.VtTabletExtraArgs = append(clusterInstance.VtTabletExtraArgs,
@@ -103,6 +102,10 @@ func TestMain(m *testing.M) {
 		if err := clusterInstance.StartVtgate(); err != nil {
 			return 1
 		}
+		clusterInstance.VtgateProcess.Config.TransactionMode = "TWOPC"
+		if err := clusterInstance.VtgateProcess.RewriteConfiguration(); err != nil {
+			return 1
+		}
 		vtParams = clusterInstance.GetVTParams(keyspaceName)
 		vtgateGrpcAddress = fmt.Sprintf("%s:%d", clusterInstance.Hostname, clusterInstance.VtgateGrpcPort)
 
diff --git a/go/vt/vtgate/vtgate.go b/go/vt/vtgate/vtgate.go
index ee9ff947333..a1dcd3219f6 100644
--- a/go/vt/vtgate/vtgate.go
+++ b/go/vt/vtgate/vtgate.go
@@ -212,10 +212,6 @@ func init() {
 	servenv.OnParseFor("vtcombo", registerFlags)
 }
 
-func getTxMode() vtgatepb.TransactionMode {
-	return transactionMode.Get()
-}
-
 var (
 	// vschemaCounters needs to be initialized before planner to
 	// catch the initial load stats.