mirror of
https://github.com/gravitational/teleport
synced 2024-10-21 01:34:01 +00:00
98 lines
3.5 KiB
Go
98 lines
3.5 KiB
Go
/*
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Copyright 2021 Gravitational, Inc.
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Licensed under the Apache License, Version 2.0 (the "License");
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you may not use this file except in compliance with the License.
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You may obtain a copy of the License at
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http://www.apache.org/licenses/LICENSE-2.0
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Unless required by applicable law or agreed to in writing, software
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distributed under the License is distributed on an "AS IS" BASIS,
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WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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See the License for the specific language governing permissions and
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limitations under the License.
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*/
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package metadata
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import (
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"context"
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"google.golang.org/grpc"
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"google.golang.org/grpc/metadata"
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"github.com/gravitational/teleport/api"
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)
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const (
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VersionKey = "version"
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)
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// defaultMetadata returns the default metadata which will be added to all outgoing calls.
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func defaultMetadata() map[string]string {
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return map[string]string{
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VersionKey: api.Version,
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}
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}
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// AddMetadataToContext returns a new context copied from ctx with the given
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// raw metadata added. Metadata already set on the given context for any key
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// will not be overridden, but new key/value pairs will always be added.
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func AddMetadataToContext(ctx context.Context, raw map[string]string) context.Context {
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md := metadata.New(raw)
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if existingMd, ok := metadata.FromOutgoingContext(ctx); ok {
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for key, vals := range existingMd {
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md.Set(key, vals...)
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}
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}
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return metadata.NewOutgoingContext(ctx, md)
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}
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// DisableInterceptors can be set on the client context with context.WithValue(ctx, DisableInterceptors{}, struct{}{})
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// to stop the client interceptors from adding any metadata to the context (useful for testing).
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type DisableInterceptors struct{}
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// StreamServerInterceptor intercepts a GRPC client stream call and adds
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// default metadata to the context.
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func StreamServerInterceptor(srv interface{}, stream grpc.ServerStream, info *grpc.StreamServerInfo, handler grpc.StreamHandler) error {
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if disable := stream.Context().Value(DisableInterceptors{}); disable == nil {
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header := metadata.New(defaultMetadata())
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grpc.SendHeader(stream.Context(), header)
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}
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return handler(srv, stream)
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}
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// StreamClientInterceptor intercepts a GRPC client stream call and adds
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// default metadata to the context.
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func StreamClientInterceptor(ctx context.Context, desc *grpc.StreamDesc, cc *grpc.ClientConn, method string, streamer grpc.Streamer, opts ...grpc.CallOption) (grpc.ClientStream, error) {
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if disable := ctx.Value(DisableInterceptors{}); disable == nil {
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ctx = AddMetadataToContext(ctx, defaultMetadata())
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}
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return streamer(ctx, desc, cc, method, opts...)
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}
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// UnaryClientInterceptor intercepts a GRPC client unary call and adds default
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// metadata to the context.
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func UnaryClientInterceptor(ctx context.Context, method string, req, reply interface{}, cc *grpc.ClientConn, invoker grpc.UnaryInvoker, opts ...grpc.CallOption) error {
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if disable := ctx.Value(DisableInterceptors{}); disable == nil {
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ctx = AddMetadataToContext(ctx, defaultMetadata())
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}
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return invoker(ctx, method, req, reply, cc, opts...)
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}
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// ClientVersionFromContext can be called from a GRPC server method to return
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// the client version that was added to the GRPC metadata by
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// StreamClientInterceptor or UnaryClientInterceptor on the client.
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func ClientVersionFromContext(ctx context.Context) (string, bool) {
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md, ok := metadata.FromIncomingContext(ctx)
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if !ok {
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return "", false
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}
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versionList := md.Get(VersionKey)
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if len(versionList) != 1 {
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return "", false
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}
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return versionList[0], true
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}
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