test: add e2e test for allowing cross cell promotion

Signed-off-by: Manan Gupta <manan@planetscale.com>

go/test/endtoend/reparent/plannedreparent/reparent_test.go

@@ -125,14 +125,8 @@ func TestReparentReplicaOffline(t *testing.T) {
 	require.Error(t, err)
 
 	// Assert that PRS failed
-	if clusterInstance.VtctlMajorVersion <= 17 {
-		assert.True(t, utils.SetReplicationSourceFailed(tablets[3], out))
-		utils.CheckPrimaryTablet(t, clusterInstance, tablets[1])
-	} else {
-		assert.Contains(t, out, "rpc error: code = DeadlineExceeded desc")
-		utils.CheckPrimaryTablet(t, clusterInstance, tablets[0])
-	}
-
+	assert.Contains(t, out, "rpc error: code = DeadlineExceeded desc")
+	utils.CheckPrimaryTablet(t, clusterInstance, tablets[0])
 }
 
 func TestReparentAvoid(t *testing.T) {
@@ -155,20 +149,32 @@ func TestReparentAvoid(t *testing.T) {
 	require.NoError(t, err)
 	utils.ValidateTopology(t, clusterInstance, false)
 
-	// tablets[1 is in the same cell and tablets[3] is in a different cell, so we must land on tablets[1
+	// tablets[1] is in the same cell and tablets[3] is in a different cell, so we must land on tablets[1]
 	utils.CheckPrimaryTablet(t, clusterInstance, tablets[1])
 
 	// If we kill the tablet in the same cell as primary then reparent --avoid_tablet will fail.
 	utils.StopTablet(t, tablets[0], true)
 	out, err := utils.PrsAvoid(t, clusterInstance, tablets[1])
 	require.Error(t, err)
-	if clusterInstance.VtctlMajorVersion <= 17 {
-		assert.Contains(t, out, "cannot find a tablet to reparent to in the same cell as the current primary")
-	} else {
-		assert.Contains(t, out, "rpc error: code = DeadlineExceeded desc = latest balancer error")
-	}
+	assert.Contains(t, out, "rpc error: code = DeadlineExceeded desc = latest balancer error")
 	utils.ValidateTopology(t, clusterInstance, false)
 	utils.CheckPrimaryTablet(t, clusterInstance, tablets[1])
+
+	t.Run("Allow cross cell promotion", func(t *testing.T) {
+		if clusterInstance.VtctlMajorVersion <= 20 {
+			t.Skip("Allow Cross Cell Promotion was added in v21")
+		}
+		utils.DeleteTablet(t, clusterInstance, tablets[0])
+		// Perform a graceful reparent operation and verify it fails because we have no replicas in the same cell as the primary.
+		out, err = utils.PrsAvoid(t, clusterInstance, tablets[1])
+		require.Error(t, err)
+		assert.Contains(t, out, "is not in the same cell as the previous primary")
+
+		// If we run PRS with allow cross cell promotion then it should succeed and should promote the replica in another cell.
+		_, err = utils.PrsAvoid(t, clusterInstance, tablets[1], "--allow-cross-cell-promotion")
+		require.NoError(t, err)
+		utils.CheckPrimaryTablet(t, clusterInstance, tablets[3])
+	})
 }
 
 func TestReparentFromOutside(t *testing.T) {

go/test/endtoend/reparent/utils/utils.go

@@ -293,17 +293,17 @@ func execute(t *testing.T, conn *mysql.Conn, query string) *sqltypes.Result {
 // region ers, prs
 
 // Prs runs PRS
-func Prs(t *testing.T, clusterInstance *cluster.LocalProcessCluster, tab *cluster.Vttablet) (string, error) {
-	return PrsWithTimeout(t, clusterInstance, tab, false, "", "")
+func Prs(t *testing.T, clusterInstance *cluster.LocalProcessCluster, tab *cluster.Vttablet, extraArgs ...string) (string, error) {
+	return PrsWithTimeout(t, clusterInstance, tab, false, "", "", extraArgs...)
 }
 
 // PrsAvoid runs PRS
-func PrsAvoid(t *testing.T, clusterInstance *cluster.LocalProcessCluster, tab *cluster.Vttablet) (string, error) {
-	return PrsWithTimeout(t, clusterInstance, tab, true, "", "")
+func PrsAvoid(t *testing.T, clusterInstance *cluster.LocalProcessCluster, tab *cluster.Vttablet, extraArgs ...string) (string, error) {
+	return PrsWithTimeout(t, clusterInstance, tab, true, "", "", extraArgs...)
 }
 
 // PrsWithTimeout runs PRS
-func PrsWithTimeout(t *testing.T, clusterInstance *cluster.LocalProcessCluster, tab *cluster.Vttablet, avoid bool, actionTimeout, waitTimeout string) (string, error) {
+func PrsWithTimeout(t *testing.T, clusterInstance *cluster.LocalProcessCluster, tab *cluster.Vttablet, avoid bool, actionTimeout, waitTimeout string, extraArgs ...string) (string, error) {
 	args := []string{
 		"PlannedReparentShard",
 		fmt.Sprintf("%s/%s", KeyspaceName, ShardName)}
@@ -319,6 +319,7 @@ func PrsWithTimeout(t *testing.T, clusterInstance *cluster.LocalProcessCluster,
 		args = append(args, "--new-primary")
 	}
 	args = append(args, tab.Alias)
+	args = append(args, extraArgs...)
 	out, err := clusterInstance.VtctldClientProcess.ExecuteCommandWithOutput(args...)
 	return out, err
 }