http

README

HTTP module

How to use

$ go get github.com/tel-io/instrumentation/middleware/http@latest

Client

import (
    "github.com/tel-io/tel/v2"
	mw "github.com/tel-io/instrumentation/middleware/http"
)

func main(){
    t, closer := tel.New(context.Background(), tel.GetConfigFromEnv())
    defer closer()

	// create wrapped client
    client:= mw.NewClient(nil)

	ctx, span := t.StartSpan(context.Background(), path, trace.WithAttributes(semconv.PeerServiceKey.String("ExampleService")))
    defer span.End()

	// create context based request
    req, _ := http.NewRequestWithContext(ctx, "GET", u.String(), nil)
	//
    res, err := client.Do(req)
}

Server

import (
    mw "github.com/tel-io/instrumentation/middleware/http"
)

func (s *Server) Start(ctx context.Context) (err error) {
	m := mw.ServerMiddlewareAll()

	mx := http.NewServeMux()
	mx.Handle("/hello", m(http.HandlerFunc(s.helloHttp)))
	mx.Handle("/crash", m(http.HandlerFunc(s.crashHttp)))
	mx.Handle("/error", m(http.HandlerFunc(s.errorHttp)))

	srv := &http.Server{}
	srv.Handler = mx
}

Documentation

Index

• Variables
• func DefaultURI(r *http.Request) string
• func NewClient(ca []byte, opts ...Option) *http.Client
• func UpdateClient(c *http.Client, opts ...Option) *http.Client
• type Checker
  • func NewChecker(url string) Checker
  • func NewDomainWithTimeout(url string, timeout time.Duration) Checker
  • func (u Checker) Check(ctx context.Context) health.ReportDocument
• type Middleware
  • func ServerMiddleware(opts ...Option) Middleware
  • func ServerMiddlewareAll(opts ...Option) Middleware
• type Option
  • func WithDumpPayloadOnError(enable bool) Option
  • func WithDumpRequest(enable bool) Option
  • func WithDumpResponse(enable bool) Option
  • func WithFilter(f ...otelhttp.Filter) Option
  • func WithHeaders(enable bool) Option
  • func WithOperation(name string) Option
  • func WithOtelOpts(opts ...otelhttp.Option) Option
  • func WithPathExtractor(in PathExtractor) Option
  • func WithTel(t *tel.Telemetry) Option
• type PathExtractor
• type TracedServeMux
  • func NewServeMux(opts ...Option) *TracedServeMux
  • func (tm *TracedServeMux) Handle(pattern string, handler http.Handler)
  • func (tm *TracedServeMux) ServeHTTP(w http.ResponseWriter, r *http.Request)

Variables

var (
	DefaultSpanNameFormatter = func(_ string, r *http.Request) string {
		var b strings.Builder

		b.WriteString(r.Method)
		b.WriteString(":")
		b.WriteString(decreasePathCardinality(r.URL.Path))

		return b.String()
	}

	DefaultFilter = func(r *http.Request) bool {
		if k, ok := r.Header["Upgrade"]; ok {
			for _, v := range k {
				if v == "websocket" {
					return false
				}
			}
		}

		return !(r.Method == http.MethodGet && strings.HasPrefix(r.URL.RequestURI(), "/health"))
	}
)

Functions

func DefaultURI

func DefaultURI(r *http.Request) string

func NewClient

func NewClient(ca []byte, opts ...Option) *http.Client

NewClient with CA injection

func UpdateClient

func UpdateClient(c *http.Client, opts ...Option) *http.Client

UpdateClient inject tracer

Types

type Checker

type Checker struct {
	URL     string
	Timeout time.Duration
}

func NewChecker

func NewChecker(url string) Checker

func NewDomainWithTimeout

func NewDomainWithTimeout(url string, timeout time.Duration) Checker

func (Checker) Check

func (u Checker) Check(ctx context.Context) health.ReportDocument

type Middleware

type Middleware func(next http.Handler) http.Handler

func ServerMiddleware

func ServerMiddleware(opts ...Option) Middleware

ServerMiddleware perform: * telemetry log injection * measure execution time * recovery

func ServerMiddlewareAll

func ServerMiddlewareAll(opts ...Option) Middleware

ServerMiddlewareAll represent all essential metrics Execution order:

• opentracing injection via nethttp.Middleware
• recovery + measure execution time + debug log via own ServerMiddleware
• metrics via metrics.NewHTTPMiddlewareWithOption

type Option

type Option interface {
	// contains filtered or unexported methods
}

Option interface used for setting optional config properties.

func WithDumpPayloadOnError

func WithDumpPayloadOnError(enable bool) Option

WithDumpPayloadOnError write dump request and response on faults

Default: true

func WithDumpRequest

func WithDumpRequest(enable bool) Option

WithDumpRequest dump request as plain text to log and trace i guess we can go further and perform option with encoding requests

func WithDumpResponse

func WithDumpResponse(enable bool) Option

WithDumpResponse dump response as plain text to log and trace

func WithFilter

func WithFilter(f ...otelhttp.Filter) Option

WithFilter append filter to default

func WithHeaders

func WithHeaders(enable bool) Option

WithHeaders explicitly set possibility to write http headers

func WithOperation

func WithOperation(name string) Option

func WithOtelOpts

func WithOtelOpts(opts ...otelhttp.Option) Option

func WithPathExtractor

func WithPathExtractor(in PathExtractor) Option

func WithTel

func WithTel(t *tel.Telemetry) Option

WithTel also add options to pass own metric and trace provider

type PathExtractor

type PathExtractor func(r *http.Request) string

type TracedServeMux

type TracedServeMux struct {
	// contains filtered or unexported fields
}

TracedServeMux is a wrapper around http.ServeMux that instruments handlers for tracing.

func NewServeMux

func NewServeMux(opts ...Option) *TracedServeMux

NewServeMux creates a new TracedServeMux.

func (*TracedServeMux) Handle

func (tm *TracedServeMux) Handle(pattern string, handler http.Handler)

Handle implements http.ServeMux#Handle

func (*TracedServeMux) ServeHTTP

func (tm *TracedServeMux) ServeHTTP(w http.ResponseWriter, r *http.Request)

ServeHTTP implements http.ServeMux#ServeHTTP