Documentation
¶
Index ¶
Examples ¶
Constants ¶
This section is empty.
Variables ¶
This section is empty.
Functions ¶
This section is empty.
Types ¶
type Trace ¶
type Trace struct {
Propagation propagation.HTTPFormat
IsPublicEndpoint bool
FormatSpanName func(r *http.Request) string
StartOptions trace.StartOptions
GetStartOptions func(r *http.Request) trace.StartOptions
}
Trace middleware
Example ¶
Sample only a fraction of requests so a high-traffic edge does not export a span for every request, and label spans with the path instead of the full URL.
package main
import (
"net/http"
octrace "go.opencensus.io/trace"
"github.com/moonrhythm/parapet"
"github.com/moonrhythm/parapet/pkg/trace"
)
func main() {
m := trace.New()
m.StartOptions.Sampler = octrace.ProbabilitySampler(0.05) // ~5% of traces
m.FormatSpanName = func(r *http.Request) string {
return r.Method + " " + r.URL.Path
}
s := parapet.New()
s.Use(m)
}
Output:
Example (GetStartOptions) ¶
Decide sampling per request: always sample internal/debug traffic, fall back to a low probability for everything else.
package main
import (
"net/http"
"strings"
octrace "go.opencensus.io/trace"
"github.com/moonrhythm/parapet"
"github.com/moonrhythm/parapet/pkg/trace"
)
func main() {
always := octrace.StartOptions{Sampler: octrace.AlwaysSample()}
sampled := octrace.StartOptions{Sampler: octrace.ProbabilitySampler(0.01)}
m := trace.New()
m.GetStartOptions = func(r *http.Request) octrace.StartOptions {
if strings.HasPrefix(r.URL.Path, "/internal/") {
return always
}
return sampled
}
s := parapet.New()
s.Use(m)
}
Output:
Example (Propagation) ¶
Read incoming trace context using the B3 headers (X-B3-TraceId, ...) emitted by Zipkin-style clients instead of the default format, so spans join the caller's trace. Mark this hop as a public endpoint so an untrusted client's span context starts a fresh, linked trace rather than being trusted as parent.
package main
import (
"go.opencensus.io/plugin/ochttp/propagation/b3"
"github.com/moonrhythm/parapet"
"github.com/moonrhythm/parapet/pkg/trace"
)
func main() {
m := trace.New()
m.Propagation = &b3.HTTPFormat{}
m.IsPublicEndpoint = true
s := parapet.New()
s.Use(m)
}
Output:
func New ¶
func New() *Trace
New creates new trace middleware
Example ¶
Add OpenCensus server-side tracing to the proxy. Each request becomes a span; an exporter registered elsewhere (Stackdriver, Zipkin, ...) ships them.
package main
import (
"github.com/moonrhythm/parapet"
"github.com/moonrhythm/parapet/pkg/trace"
)
func main() {
s := parapet.New()
s.Use(trace.New())
// s.Use(upstream.SingleHost("10.0.0.1:8080")) — the proxied handler runs inside the span.
}
Output:
Source Files