| // Copyright 2019 The LUCI Authors. |
| // |
| // 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 flag |
| |
| import ( |
| "flag" |
| "fmt" |
| "sort" |
| "strings" |
| |
| "google.golang.org/grpc/metadata" |
| ) |
| |
| // metadataFlag implements the flag.Getter returned by GRPCMetadata. |
| type grpcMetadataFlag metadata.MD |
| |
| // GRPCMetadata returns a flag.Getter for parsing gRPC metadata from a |
| // a set of colon-separated strings. |
| // Example: -f a:1 -f a:2 -f b:3 |
| // Panics if md is nil. |
| func GRPCMetadata(md metadata.MD) flag.Getter { |
| if md == nil { |
| panic("md is nil") |
| } |
| return grpcMetadataFlag(md) |
| } |
| |
| // String implements the flag.Value interface. |
| func (f grpcMetadataFlag) String() string { |
| pairs := make([]string, 0, len(f)) |
| for k, vs := range f { |
| for _, v := range vs { |
| pairs = append(pairs, fmt.Sprintf("%s:%s", k, v)) |
| } |
| } |
| sort.Strings(pairs) |
| return strings.Join(pairs, ", ") |
| } |
| |
| // Set implements the flag.Value interface. |
| func (f grpcMetadataFlag) Set(s string) error { |
| parts := strings.Split(s, ":") |
| if len(parts) == 1 { |
| return fmt.Errorf("no colon") |
| } |
| metadata.MD(f).Append(parts[0], parts[1]) |
| return nil |
| } |
| |
| // Get retrieves the flag value. |
| func (f grpcMetadataFlag) Get() any { |
| return metadata.MD(f) |
| } |