fix: Make sure DNS domain names properly parse as a CDS server URI

cmd/stunnerd/main.go

@@ -19,7 +19,7 @@ import (
 
 func main() {
 	os.Args[0] = "stunnerd"
-	var config = flag.StringP("config", "c", "", "Config origin, either a valid IP address or URL to the CDS server, or a file name (overrides: STUNNER_CONFIG_ORIGIN)")
+	var config = flag.StringP("config", "c", "", "Config origin, either a valid address in the format IP:port, or HTTP URL to the CDS server, or a proper file name URI in the format file://<path-to-config-file> (overrides: STUNNER_CONFIG_ORIGIN)")
 	var level = flag.StringP("log", "l", "", "Log level (format: <scope>:<level>, overrides: PION_LOG_*, default: all:INFO)")
 	var id = flag.StringP("id", "i", "", "Id for identifying with the CDS server (format: <namespace>/<name>, overrides: STUNNER_NAMESPACE/STUNNER_NAME, default: <default/stunnerd-hostname>)")
 	var watch = flag.BoolP("watch", "w", false, "Watch config file for updates (default: false)")

config_test.go

@@ -153,7 +153,8 @@ func TestStunnerConfigFileWatcher(t *testing.T) {
 	ctx, cancel := context.WithCancel(context.Background())
 	defer cancel()
 
-	err = stunner.WatchConfig(ctx, file, conf)
+	url := "file://" + file
+	err = stunner.WatchConfig(ctx, url, conf)
 	assert.NoError(t, err, "creating config watcher")
 
 	// nothing should happen here: wait a bit so that the watcher has comfortable time to start
@@ -266,7 +267,9 @@ func TestStunnerConfigFileWatcherMultiVersion(t *testing.T) {
 	log.Debug("init watcher with nonexistent config file")
 	ctx, cancel := context.WithCancel(context.Background())
 	defer cancel()
-	err = stunner.WatchConfig(ctx, file, conf)
+
+	url := "file://" + file
+	err = stunner.WatchConfig(ctx, url, conf)
 	assert.NoError(t, err, "creating config watcher")
 
 	// nothing should happen here: wait a bit so that the watcher has comfortable time to start

pkg/config/client/client.go

@@ -42,7 +42,9 @@ type Client interface {
 	fmt.Stringer
 }
 
-// New creates a generic config client.
+// New creates a generic config client. Origin is either a network address in the form
+// "<IP>:<port>" or a proper HTTP/WS URI, in which case a CDS client is returned, or a proper file
+// URL "file://<path>/<filename>" in which case a config file watcher is returned.
 func New(origin string, id string, logger logging.LoggerFactory) (Client, error) {
 	u, err := getURI(origin)
 	if err != nil {

pkg/config/client/client_test.go

@@ -10,7 +10,7 @@ func TestParseURI(t *testing.T) {
 	// file
 	u, err := getURI("/tmp/a")
 	assert.NoError(t, err, "file URI parse")
-	assert.Equal(t, "", u.Scheme, "file URI scheme")
+	assert.Equal(t, "http", u.Scheme, "file URI scheme")
 	assert.Equal(t, "", u.Host, "file URI host")
 	assert.Equal(t, "/tmp/a", u.Path, "file URI path")
 

pkg/config/client/file_client.go

@@ -5,6 +5,7 @@ import (
 	"errors"
 	"fmt"
 	"os"
+	"strings"
 	"time"
 
 	"github.com/fsnotify/fsnotify"
@@ -25,6 +26,8 @@ type ConfigFileClient struct {
 // NewConfigFileClient creates a client that load or watch STUNner configurations from a local
 // file.
 func NewConfigFileClient(origin, id string, logger logging.LeveledLogger) (Client, error) {
+	origin = strings.TrimPrefix(origin, "file://") // returns original if there is no "file://" prefix
+
 	return &ConfigFileClient{
 		configFile: origin,
 		id:         id,

pkg/config/client/util.go

@@ -3,6 +3,7 @@ package client
 import (
 	"encoding/json"
 	"net/url"
+	"strings"
 
 	stnrv1 "github.com/l7mp/stunner/pkg/apis/v1"
 )
@@ -28,14 +29,16 @@ func decodeConfigList(r []byte) ([]*stnrv1.StunnerConfig, error) {
 
 // getURI tries to parse an address or an URL or a file name into an URL.
 func getURI(addr string) (*url.URL, error) {
+	// make sure we have a working HTTP scheme
+	if !strings.HasPrefix(addr, "http://") && !strings.HasPrefix(addr, "https://") &&
+		!strings.HasPrefix(addr, "ws://") && !strings.HasPrefix(addr, "wss://") &&
+		!strings.HasPrefix(addr, "file://") {
+		addr = "http://" + addr
+	}
+
 	url, err := url.Parse(addr)
 	if err != nil {
-		// try to parse with a http scheme as a last resort
-		u, err2 := url.Parse("http://" + addr)
-		if err2 != nil {
-			return nil, err
-		}
-		url = u
+		return nil, err
 	}
 	return url, nil
 }

stunner_test.go

@@ -37,7 +37,6 @@ var stunnerTestLoglevel string = "all:ERROR"
 // var stunnerTestLoglevel string = stnrv1.DefaultLogLevel
 // var stunnerTestLoglevel string = "all:INFO"
 // var stunnerTestLoglevel string = "all:TRACE"
-
 // var stunnerTestLoglevel string = "all:TRACE,vnet:INFO,turn:ERROR,turnc:ERROR"
 
 var certPem, keyPem, _ = GenerateSelfSignedKey()