forked from elastic/apm-agent-go
/
middleware.go
102 lines (91 loc) · 2.36 KB
/
middleware.go
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package apmecho
import (
"errors"
"fmt"
"github.com/labstack/echo"
"github.com/elastic/apm-agent-go"
"github.com/elastic/apm-agent-go/module/apmhttp"
)
// Middleware returns a new Echo middleware handler for tracing
// requests and reporting errors.
//
// This middleware will recover and report panics, so it can
// be used instead of echo/middleware.Recover.
//
// By default, the middleware will use elasticapm.DefaultTracer.
// Use WithTracer to specify an alternative tracer.
func Middleware(o ...Option) echo.MiddlewareFunc {
opts := options{tracer: elasticapm.DefaultTracer}
for _, o := range o {
o(&opts)
}
return func(h echo.HandlerFunc) echo.HandlerFunc {
m := &middleware{tracer: opts.tracer, handler: h}
return m.handle
}
}
type middleware struct {
handler echo.HandlerFunc
tracer *elasticapm.Tracer
}
func (m *middleware) handle(c echo.Context) error {
if !m.tracer.Active() {
return m.handler(c)
}
req := c.Request()
name := req.Method + " " + c.Path()
tx := m.tracer.StartTransaction(name, "request")
ctx := elasticapm.ContextWithTransaction(req.Context(), tx)
req = apmhttp.RequestWithContext(ctx, req)
c.SetRequest(req)
defer tx.End()
body := m.tracer.CaptureHTTPRequestBody(req)
defer func() {
if v := recover(); v != nil {
e := m.tracer.Recovered(v, tx)
e.Context.SetHTTPRequest(req)
e.Context.SetHTTPRequestBody(body)
err, ok := v.(error)
if !ok {
err = errors.New(fmt.Sprint(v))
}
e.Send()
c.Error(err)
}
}()
resp := c.Response()
handlerErr := m.handler(c)
tx.Result = apmhttp.StatusCodeResult(resp.Status)
if tx.Sampled() {
tx.Context.SetHTTPRequest(req)
tx.Context.SetHTTPRequestBody(body)
tx.Context.SetHTTPStatusCode(resp.Status)
tx.Context.SetHTTPResponseHeaders(resp.Header())
tx.Context.SetHTTPResponseHeadersSent(resp.Committed)
}
if handlerErr != nil {
e := m.tracer.NewError(handlerErr)
e.Context.SetHTTPRequest(req)
e.Context.SetHTTPRequestBody(body)
e.Transaction = tx
e.Handled = true
e.Send()
return handlerErr
}
return nil
}
type options struct {
tracer *elasticapm.Tracer
}
// Option sets options for tracing.
type Option func(*options)
// WithTracer returns an Option which sets t as the tracer
// to use for tracing server requests.
func WithTracer(t *elasticapm.Tracer) Option {
if t == nil {
panic("t == nil")
}
return func(o *options) {
o.tracer = t
}
}