Retry initial connection attempt should it fail (#1335)

Sometimes the initial selected node could fail. In that case, we'll give it a few more attempts to locate a media node for the session instead of failing it after the first try.

pkg/utils/context.go

@@ -0,0 +1,32 @@
+/*
+ * Copyright 2023 LiveKit, Inc
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package utils
+
+import "context"
+
+var attemptKey = struct{}{}
+
+func ContextWithAttempt(ctx context.Context, attempt int) context.Context {
+	return context.WithValue(ctx, attemptKey, attempt)
+}
+
+func GetAttempt(ctx context.Context) int {
+	if attempt, ok := ctx.Value(attemptKey).(int); ok {
+		return attempt
+	}
+	return 0
+}