mirror of
https://github.com/octoleo/restic.git
synced 2024-12-02 09:58:25 +00:00
109 lines
4.1 KiB
Go
109 lines
4.1 KiB
Go
// Copyright 2017 Google Inc. All Rights Reserved.
|
|
//
|
|
// 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 trace
|
|
|
|
import (
|
|
"encoding/hex"
|
|
"fmt"
|
|
|
|
"cloud.google.com/go/internal/tracecontext"
|
|
"golang.org/x/net/context"
|
|
"google.golang.org/grpc"
|
|
"google.golang.org/grpc/metadata"
|
|
)
|
|
|
|
const grpcMetadataKey = "grpc-trace-bin"
|
|
|
|
// GRPCClientInterceptor returns a grpc.UnaryClientInterceptor that traces all outgoing requests from a gRPC client.
|
|
// The calling context should already have a *trace.Span; a child span will be
|
|
// created for the outgoing gRPC call. If the calling context doesn't have a span,
|
|
// the call will not be traced. If the client is nil, then the interceptor just
|
|
// passes through the request.
|
|
//
|
|
// The functionality in gRPC that this feature relies on is currently experimental.
|
|
func (c *Client) GRPCClientInterceptor() grpc.UnaryClientInterceptor {
|
|
if c == nil {
|
|
return func(ctx context.Context, method string, req, reply interface{}, cc *grpc.ClientConn, invoker grpc.UnaryInvoker, opts ...grpc.CallOption) error {
|
|
return invoker(ctx, method, req, reply, cc, opts...)
|
|
}
|
|
}
|
|
return grpc.UnaryClientInterceptor(c.grpcUnaryInterceptor)
|
|
}
|
|
|
|
func (c *Client) grpcUnaryInterceptor(ctx context.Context, method string, req, reply interface{}, cc *grpc.ClientConn, invoker grpc.UnaryInvoker, opts ...grpc.CallOption) error {
|
|
// TODO: also intercept streams.
|
|
span := FromContext(ctx).NewChild(method)
|
|
if span == nil {
|
|
span = c.NewSpan(method)
|
|
}
|
|
defer span.Finish()
|
|
|
|
traceContext := make([]byte, tracecontext.Len)
|
|
// traceID is a hex-encoded 128-bit value.
|
|
// TODO(jbd): Decode trace IDs upon arrival and
|
|
// represent trace IDs with 16 bytes internally.
|
|
tid, err := hex.DecodeString(span.trace.traceID)
|
|
if err != nil {
|
|
return invoker(ctx, method, req, reply, cc, opts...)
|
|
}
|
|
tracecontext.Encode(traceContext, tid, span.span.SpanId, byte(span.trace.globalOptions))
|
|
md, ok := metadata.FromOutgoingContext(ctx)
|
|
if !ok {
|
|
md = metadata.Pairs(grpcMetadataKey, string(traceContext))
|
|
} else {
|
|
md = md.Copy() // metadata is immutable, copy.
|
|
md[grpcMetadataKey] = []string{string(traceContext)}
|
|
}
|
|
ctx = metadata.NewOutgoingContext(ctx, md)
|
|
|
|
err = invoker(ctx, method, req, reply, cc, opts...)
|
|
if err != nil {
|
|
// TODO: standardize gRPC label names?
|
|
span.SetLabel("error", err.Error())
|
|
}
|
|
return err
|
|
}
|
|
|
|
// GRPCServerInterceptor returns a grpc.UnaryServerInterceptor that enables the tracing of the incoming
|
|
// gRPC calls. Incoming call's context can be used to extract the span on servers that enabled this option:
|
|
//
|
|
// span := trace.FromContext(ctx)
|
|
//
|
|
// If the client is nil, then the interceptor just invokes the handler.
|
|
//
|
|
// The functionality in gRPC that this feature relies on is currently experimental.
|
|
func (c *Client) GRPCServerInterceptor() grpc.UnaryServerInterceptor {
|
|
if c == nil {
|
|
return func(ctx context.Context, req interface{}, _ *grpc.UnaryServerInfo, handler grpc.UnaryHandler) (interface{}, error) {
|
|
return handler(ctx, req)
|
|
}
|
|
}
|
|
return func(ctx context.Context, req interface{}, info *grpc.UnaryServerInfo, handler grpc.UnaryHandler) (resp interface{}, err error) {
|
|
md, _ := metadata.FromIncomingContext(ctx)
|
|
var traceHeader string
|
|
if header, ok := md[grpcMetadataKey]; ok {
|
|
traceID, spanID, opts, ok := tracecontext.Decode([]byte(header[0]))
|
|
if ok {
|
|
// TODO(jbd): Generate a span directly from string(traceID), spanID and opts.
|
|
traceHeader = fmt.Sprintf("%x/%d;o=%d", traceID, spanID, opts)
|
|
}
|
|
}
|
|
span := c.SpanFromHeader(info.FullMethod, traceHeader)
|
|
defer span.Finish()
|
|
ctx = NewContext(ctx, span)
|
|
return handler(ctx, req)
|
|
}
|
|
}
|