1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
|
package opentracing
import (
"context"
"net"
"net/http"
"strconv"
opentracing "github.com/opentracing/opentracing-go"
"github.com/opentracing/opentracing-go/ext"
kithttp "github.com/go-kit/kit/transport/http"
"github.com/go-kit/log"
)
// ContextToHTTP returns an http RequestFunc that injects an OpenTracing Span
// found in `ctx` into the http headers. If no such Span can be found, the
// RequestFunc is a noop.
func ContextToHTTP(tracer opentracing.Tracer, logger log.Logger) kithttp.RequestFunc {
return func(ctx context.Context, req *http.Request) context.Context {
// Try to find a Span in the Context.
if span := opentracing.SpanFromContext(ctx); span != nil {
// Add standard OpenTracing tags.
ext.HTTPMethod.Set(span, req.Method)
ext.HTTPUrl.Set(span, req.URL.String())
host, portString, err := net.SplitHostPort(req.URL.Host)
if err == nil {
ext.PeerHostname.Set(span, host)
if port, err := strconv.Atoi(portString); err == nil {
ext.PeerPort.Set(span, uint16(port))
}
} else {
ext.PeerHostname.Set(span, req.URL.Host)
}
// There's nothing we can do with any errors here.
if err = tracer.Inject(
span.Context(),
opentracing.HTTPHeaders,
opentracing.HTTPHeadersCarrier(req.Header),
); err != nil {
logger.Log("err", err)
}
}
return ctx
}
}
// HTTPToContext returns an http RequestFunc that tries to join with an
// OpenTracing trace found in `req` and starts a new Span called
// `operationName` accordingly. If no trace could be found in `req`, the Span
// will be a trace root. The Span is incorporated in the returned Context and
// can be retrieved with opentracing.SpanFromContext(ctx).
func HTTPToContext(tracer opentracing.Tracer, operationName string, logger log.Logger) kithttp.RequestFunc {
return func(ctx context.Context, req *http.Request) context.Context {
// Try to join to a trace propagated in `req`.
var span opentracing.Span
wireContext, err := tracer.Extract(
opentracing.HTTPHeaders,
opentracing.HTTPHeadersCarrier(req.Header),
)
if err != nil && err != opentracing.ErrSpanContextNotFound {
logger.Log("err", err)
}
span = tracer.StartSpan(operationName, ext.RPCServerOption(wireContext))
ext.HTTPMethod.Set(span, req.Method)
ext.HTTPUrl.Set(span, req.URL.String())
return opentracing.ContextWithSpan(ctx, span)
}
}
|
