| // Licensed to the Apache Software Foundation (ASF) under one or more |
| // contributor license agreements. See the NOTICE file distributed with |
| // this work for additional information regarding copyright ownership. |
| // The ASF licenses this file to You 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 util |
| |
| import ( |
| "context" |
| "google.golang.org/grpc/metadata" |
| ) |
| |
| func FromMetadata(ctx context.Context, key string) string { |
| md, ok := metadata.FromIncomingContext(ctx) |
| if !ok { |
| return "" |
| } |
| if values, ok := md[key]; ok && len(values) > 0 { |
| return values[0] |
| } |
| return "" |
| } |