Refactor healthcheck sender and receiver to use configurable options (#4433)

shared/relay/client/manager.go

@@ -78,9 +78,10 @@ func NewManager(ctx context.Context, serverURLs []string, peerID string, mtu uin
 		tokenStore: tokenStore,
 		mtu:        mtu,
 		serverPicker: &ServerPicker{
-			TokenStore: tokenStore,
-			PeerID:     peerID,
-			MTU:        mtu,
+			TokenStore:        tokenStore,
+			PeerID:            peerID,
+			MTU:               mtu,
+			ConnectionTimeout: defaultConnectionTimeout,
 		},
 		relayClients:            make(map[string]*RelayTrack),
 		onDisconnectedListeners: make(map[string]*list.List),

shared/relay/client/picker.go

@@ -13,11 +13,8 @@ import (
 )
 
 const (
-	maxConcurrentServers = 7
-)
-
-var (
-	connectionTimeout = 30 * time.Second
+	maxConcurrentServers     = 7
+	defaultConnectionTimeout = 30 * time.Second
 )
 
 type connResult struct {
@@ -27,14 +24,15 @@ type connResult struct {
 }
 
 type ServerPicker struct {
-	TokenStore *auth.TokenStore
-	ServerURLs atomic.Value
-	PeerID     string
-	MTU        uint16
+	TokenStore        *auth.TokenStore
+	ServerURLs        atomic.Value
+	PeerID            string
+	MTU               uint16
+	ConnectionTimeout time.Duration
 }
 
 func (sp *ServerPicker) PickServer(parentCtx context.Context) (*Client, error) {
-	ctx, cancel := context.WithTimeout(parentCtx, connectionTimeout)
+	ctx, cancel := context.WithTimeout(parentCtx, sp.ConnectionTimeout)
 	defer cancel()
 
 	totalServers := len(sp.ServerURLs.Load().([]string))

shared/relay/client/picker_test.go

@@ -8,15 +8,15 @@ import (
 )
 
 func TestServerPicker_UnavailableServers(t *testing.T) {
-	connectionTimeout = 5 * time.Second
-
+	timeout := 5 * time.Second
 	sp := ServerPicker{
-		TokenStore: nil,
-		PeerID:     "test",
+		TokenStore:        nil,
+		PeerID:            "test",
+		ConnectionTimeout: timeout,
 	}
 	sp.ServerURLs.Store([]string{"rel://dummy1", "rel://dummy2"})
 
-	ctx, cancel := context.WithTimeout(context.Background(), connectionTimeout+1)
+	ctx, cancel := context.WithTimeout(context.Background(), timeout+1)
 	defer cancel()
 
 	go func() {