Server name override (#9)

* added cname override

* updated tests

cmd/grpcannon/main.go

@@ -22,6 +22,7 @@ var (
 	proto = flag.String("proto", "", `The .proto file.`)
 	call  = flag.String("call", "", `A fully-qualified symbol name.`)
 	cert  = flag.String("cert", "", "Client certificate file. If Omitted insecure is used.")
+	cname = flag.String("cname", "", "Server Cert CName Override - useful for self signed certs")
 
 	c = flag.Int("c", 50, "Number of requests to run concurrently.")
 	n = flag.Int("n", 200, "Number of requests to run. Default is 200.")
@@ -54,6 +55,7 @@ Options:
   -proto	The protocol buffer file.
   -call		A fully-qualified method name in 'service/method' or 'service.method' format.
   -cert		The file containing the CA root cert file.
+  -cname	an override of the expect Server Cname presented by the server.
 
   -c  Number of requests to run concurrently. Total number of requests cannot
 	  be smaller than the concurrency level. Default is 50.
@@ -117,7 +119,7 @@ func main() {
 			iPaths = strings.Split(pathsTrimmed, ",")
 		}
 
-		cfg, err = config.New(*proto, *call, *cert, *n, *c, *q, *z, *t,
+		cfg, err = config.New(*proto, *call, *cert, *cname, *n, *c, *q, *z, *t,
 			*data, *dataPath, *md, *mdPath, *output, *format, host, *ct, *kt, *cpus, iPaths)
 		if err != nil {
 			errAndExit(err.Error())
@@ -163,6 +165,7 @@ func runTest(config *config.Config) (*grpcannon.Report, error) {
 	opts := &grpcannon.Options{
 		Host:          config.Host,
 		Cert:          config.Cert,
+		CName:		   config.CName,
 		N:             config.N,
 		C:             config.C,
 		QPS:           config.QPS,

config/config.go

@@ -17,6 +17,7 @@ type Config struct {
 	Proto         string             `json:"proto"`
 	Call          string             `json:"call"`
 	Cert          string             `json:"cert"`
+	CName		  string			 `json:"cName"`
 	N             int                `json:"n"`
 	C             int                `json:"c"`
 	QPS           int                `json:"q"`
@@ -36,14 +37,15 @@ type Config struct {
 }
 
 // NewConfig creates a new config
-func New(proto, call, cert string, n, c, qps int, z time.Duration, timeout int,
+func New(proto, call, cert, cName string, n, c, qps int, z time.Duration, timeout int,
 	data, dataPath, metadata, mdPath, output, format, host string,
 	dialTimout, keepaliveTime, cpus int, importPaths []string) (*Config, error) {
 
 	cfg := &Config{
 		Proto:         proto,
 		Call:          call,
 		Cert:          cert,
+		CName:		   cName,
 		N:             n,
 		C:             c,
 		QPS:           qps,

config/config_test.go

@@ -11,7 +11,7 @@ import (
 	"github.com/stretchr/testify/assert"
 )
 
-const expected = `{"proto":"asdf","call":"","cert":"","n":0,"c":0,"q":0,"t":0,"D":"","M":"","o":"","O":"oval","host":"","T":0,"L":0,"cpus":0,"z":"4h30m0s"}`
+const expected = `{"proto":"asdf","call":"","cert":"","cName":"","n":0,"c":0,"q":0,"t":0,"D":"","M":"","o":"","O":"oval","host":"","T":0,"L":0,"cpus":0,"z":"4h30m0s"}`
 
 func TestConfig_MarshalJSON(t *testing.T) {
 	z, _ := time.ParseDuration("4h30m")
@@ -260,6 +260,7 @@ func TestConfig_ReadConfig(t *testing.T) {
 				Call:          "mycall",
 				Data:          data,
 				Cert:          "mycert",
+				CName: 		   "localhost",
 				N:             200,
 				C:             50,
 				QPS:           0,
@@ -298,6 +299,7 @@ func TestConfig_ReadConfig(t *testing.T) {
 				Call:          "mycall",
 				Data:          data,
 				Cert:          "mycert",
+				CName: 		   "localhost",
 				N:             200,
 				C:             50,
 				QPS:           0,

requester.go

@@ -23,6 +23,7 @@ import (
 type Options struct {
 	Host          string
 	Cert          string
+	CName		  string
 	N             int
 	C             int
 	QPS           int
@@ -300,7 +301,7 @@ func (b *Requester) makeBidiRequest(ctx *context.Context) {
 func createClientCredOption(config *Options) (grpc.DialOption, error) {
 	credOptions := grpc.WithInsecure()
 	if strings.TrimSpace(config.Cert) != "" {
-		creds, err := credentials.NewClientTLSFromFile(config.Cert, "")
+		creds, err := credentials.NewClientTLSFromFile(config.Cert, config.CName)
 		if err != nil {
 			return nil, err
 		}

testdata/cfgpath.json

@@ -2,6 +2,7 @@
     "proto": "my.proto",
     "call": "mycall",
     "cert": "mycert",
+    "cName": "localhost",
     "D": "./data.json",
     "M": "./metadata.json",
     "i": [

testdata/grpcannon.json

@@ -2,6 +2,7 @@
     "proto": "my.proto",
     "call": "mycall",
     "cert": "mycert",
+    "cName": "localhost",
     "d": {
         "name": "mydata"
     },