/
expvar.go
171 lines (150 loc) · 3.91 KB
/
expvar.go
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package main
import (
"expvar"
"flag"
"fmt"
"github.com/valyala/fasthttp"
"github.com/valyala/fasthttp/expvarhandler"
"io"
"log"
"net"
"sync/atomic"
)
var (
expvarAddr = flag.String("expvarAddr", "localhost:8040", "TCP address for exporting httptp metrics. They are exported "+
"at the following pages:\n"+
"\thttp://expvarAddr/expvar - in expvar format\n"+
"\thttp://expvarAddr/prometheus - in prometheus format\n")
)
func initExpvarServer() {
if *expvarAddr == "" {
return
}
log.Printf("exporting stats at http://%[1]s/expvar and http://%[1]s/prometheus", *expvarAddr)
go func() {
if err := fasthttp.ListenAndServe(*expvarAddr, expvarHandler); err != nil {
log.Fatalf("error in expvar server: %s", err)
}
}()
}
func expvarHandler(ctx *fasthttp.RequestCtx) {
path := ctx.Path()
switch string(path) {
case "/expvar":
expvarhandler.ExpvarHandler(ctx)
case "/prometheus":
prometheusHandler(ctx)
default:
ctx.Error("unsupported path", fasthttp.StatusBadRequest)
}
}
func prometheusHandler(ctx *fasthttp.RequestCtx) {
prometheusHandlerCalls.Add(1)
expvar.Do(func(kv expvar.KeyValue) {
if x, ok := kv.Value.(*expvar.Int); ok {
fmt.Fprintf(ctx, "# TYPE %s counter\n", kv.Key)
fmt.Fprintf(ctx, "%s %s\n", kv.Key, x)
}
})
}
func newExpvarDial(dial fasthttp.DialFunc) fasthttp.DialFunc {
return func(addr string) (net.Conn, error) {
conn, err := dial(addr)
if err != nil {
outDialError.Add(1)
return nil, err
}
outConns.Add(1)
outDialSuccess.Add(1)
return &expvarConn{
Conn: conn,
conns: outConns,
bytesWritten: outBytesWritten,
bytesRead: outBytesRead,
writeError: outWriteError,
readError: outReadError,
writeCalls: outWriteCalls,
readCalls: outReadCalls,
}, nil
}
}
type expvarConn struct {
net.Conn
conns *expvar.Int
bytesWritten *expvar.Int
bytesRead *expvar.Int
writeError *expvar.Int
readError *expvar.Int
writeCalls *expvar.Int
readCalls *expvar.Int
closed uint32
}
func (c *expvarConn) Close() error {
if atomic.AddUint32(&c.closed, 1) == 1 {
c.conns.Add(-1)
}
return c.Conn.Close()
}
func (c *expvarConn) Write(p []byte) (int, error) {
n, err := c.Conn.Write(p)
c.writeCalls.Add(1)
c.bytesWritten.Add(int64(n))
if err != nil {
c.writeError.Add(1)
}
return n, err
}
func (c *expvarConn) Read(p []byte) (int, error) {
n, err := c.Conn.Read(p)
c.readCalls.Add(1)
c.bytesRead.Add(int64(n))
if err != nil && err != io.EOF {
c.readError.Add(1)
}
return n, err
}
var (
outDialSuccess = expvar.NewInt("outDialSuccess")
outDialError = expvar.NewInt("outDialError")
outConns = expvar.NewInt("outConns")
outBytesWritten = expvar.NewInt("outBytesWritten")
outBytesRead = expvar.NewInt("outBytesRead")
outWriteError = expvar.NewInt("outWriteError")
outReadError = expvar.NewInt("outReadError")
outWriteCalls = expvar.NewInt("outWriteCalls")
outReadCalls = expvar.NewInt("outReadCalls")
prometheusHandlerCalls = expvar.NewInt("prometheusHandlerCalls")
)
type expvarListener struct {
net.Listener
}
func (ln *expvarListener) Accept() (net.Conn, error) {
conn, err := ln.Listener.Accept()
if err != nil {
inAcceptError.Add(1)
return nil, err
}
inAcceptSuccess.Add(1)
inConns.Add(1)
return &expvarConn{
Conn: conn,
conns: inConns,
bytesWritten: inBytesWritten,
bytesRead: inBytesRead,
writeError: inWriteError,
readError: inReadError,
writeCalls: inWriteCalls,
readCalls: inReadCalls,
}, nil
}
var (
inAcceptSuccess = expvar.NewInt("inAcceptSuccess")
inAcceptError = expvar.NewInt("inAcceptError")
inConns = expvar.NewInt("inConns")
inBytesWritten = expvar.NewInt("inBytesWritten")
inBytesRead = expvar.NewInt("inBytesRead")
inWriteError = expvar.NewInt("inWriteError")
inReadError = expvar.NewInt("inReadError")
inWriteCalls = expvar.NewInt("inWriteCalls")
inReadCalls = expvar.NewInt("inReadCalls")
)