86 lines
1.5 KiB
Go
86 lines
1.5 KiB
Go
package main
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import (
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"context"
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"fmt"
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"io"
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"net"
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"net/http"
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"time"
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)
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const (
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metricsAddress = ":9998"
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)
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type metricsData struct {
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countClient int64
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countPublisher int64
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countReader int64
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}
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type metricsGatherReq struct {
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res chan *metricsData
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}
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type metrics struct {
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p *program
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listener net.Listener
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mux *http.ServeMux
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server *http.Server
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}
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func newMetrics(p *program) (*metrics, error) {
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listener, err := net.Listen("tcp", metricsAddress)
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if err != nil {
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return nil, err
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}
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m := &metrics{
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p: p,
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listener: listener,
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}
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m.mux = http.NewServeMux()
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m.mux.HandleFunc("/metrics", m.onMetrics)
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m.server = &http.Server{
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Handler: m.mux,
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}
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m.p.log("[metrics] opened on " + metricsAddress)
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return m, nil
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}
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func (m *metrics) run() {
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err := m.server.Serve(m.listener)
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if err != http.ErrServerClosed {
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panic(err)
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}
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}
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func (m *metrics) close() {
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m.server.Shutdown(context.Background())
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}
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func (m *metrics) onMetrics(w http.ResponseWriter, req *http.Request) {
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res := make(chan *metricsData)
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m.p.metricsGather <- metricsGatherReq{res}
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data := <-res
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if data == nil {
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w.WriteHeader(http.StatusInternalServerError)
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return
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}
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out := ""
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now := time.Now().UnixNano() / 1000000
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out += fmt.Sprintf("clients %d %v\n", data.countClient, now)
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out += fmt.Sprintf("publishers %d %v\n", data.countPublisher, now)
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out += fmt.Sprintf("readers %d %v\n", data.countReader, now)
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w.WriteHeader(http.StatusOK)
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io.WriteString(w, out)
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}
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