63 lines
1.4 KiB
Go
63 lines
1.4 KiB
Go
|
// Package expvarhandler provides fasthttp-compatible request handler
|
||
|
|
// serving expvars.
|
||
|
|
package expvarhandler
|
||
|
|
|
||
|
|
import (
|
||
|
|
"expvar"
|
||
|
|
"fmt"
|
||
|
|
"regexp"
|
||
|
|
|
||
|
|
"github.com/valyala/fasthttp"
|
||
|
|
)
|
||
|
|
|
||
|
|
var (
|
||
|
|
expvarHandlerCalls = expvar.NewInt("expvarHandlerCalls")
|
||
|
|
expvarRegexpErrors = expvar.NewInt("expvarRegexpErrors")
|
||
|
|
)
|
||
|
|
|
||
|
|
// ExpvarHandler dumps json representation of expvars to http response.
|
||
|
|
//
|
||
|
|
// Expvars may be filtered by regexp provided via 'r' query argument.
|
||
|
|
//
|
||
|
|
// See https://golang.org/pkg/expvar/ for details.
|
||
|
|
func ExpvarHandler(ctx *fasthttp.RequestCtx) {
|
||
|
|
expvarHandlerCalls.Add(1)
|
||
|
|
|
||
|
|
ctx.Response.Reset()
|
||
|
|
|
||
|
|
r, err := getExpvarRegexp(ctx)
|
||
|
|
if err != nil {
|
||
|
|
expvarRegexpErrors.Add(1)
|
||
|
|
fmt.Fprintf(ctx, "Error when obtaining expvar regexp: %s", err)
|
||
|
|
ctx.SetStatusCode(fasthttp.StatusBadRequest)
|
||
|
|
return
|
||
|
|
}
|
||
|
|
|
||
|
|
fmt.Fprintf(ctx, "{\n")
|
||
|
|
first := true
|
||
|
|
expvar.Do(func(kv expvar.KeyValue) {
|
||
|
|
if !first {
|
||
|
|
fmt.Fprintf(ctx, ",\n")
|
||
|
|
}
|
||
|
|
if r.MatchString(kv.Key) {
|
||
|
|
first = false
|
||
|
|
fmt.Fprintf(ctx, "\t%q: %s", kv.Key, kv.Value)
|
||
|
|
}
|
||
|
|
})
|
||
|
|
fmt.Fprintf(ctx, "\n}\n")
|
||
|
|
|
||
|
|
ctx.SetContentType("application/json; charset=utf-8")
|
||
|
|
}
|
||
|
|
|
||
|
|
func getExpvarRegexp(ctx *fasthttp.RequestCtx) (*regexp.Regexp, error) {
|
||
|
|
r := string(ctx.QueryArgs().Peek("r"))
|
||
|
|
if len(r) == 0 {
|
||
|
|
r = "."
|
||
|
|
}
|
||
|
|
rr, err := regexp.Compile(r)
|
||
|
|
if err != nil {
|
||
|
|
return nil, fmt.Errorf("cannot parse r=%q: %s", r, err)
|
||
|
|
}
|
||
|
|
return rr, nil
|
||
|
|
}
|