caddy-log-exporter/internal/server/server.go
2024-09-19 11:21:05 +02:00

93 lines
1.6 KiB
Go

package server
import (
"context"
"errors"
"fmt"
"log/slog"
"net/http"
"sync"
"time"
"github.com/VictoriaMetrics/metrics"
"go.xsfx.dev/caddy-log-exporter/internal/config"
)
const metricBaseName = "caddy_log_exporter"
type Server struct {
addr string
logFiles []string
httpServer *http.Server
}
func New(c config.Config) *Server {
s := &Server{}
s.addr = c.Addr
s.logFiles = c.LogFiles
mux := http.NewServeMux()
mux.HandleFunc("/metrics", s.metrics)
s.httpServer = &http.Server{
Addr: c.Addr,
Handler: mux,
ReadHeaderTimeout: time.Second,
}
return s
}
func (s *Server) metrics(w http.ResponseWriter, _ *http.Request) {
metrics.WritePrometheus(w, false)
}
const shutdownTimeout = 10 * time.Second
func (s *Server) http(ctx context.Context, wg *sync.WaitGroup) {
go func() {
slog.Info("serving http", "addr", s.addr)
if err := s.httpServer.ListenAndServe(); !errors.Is(
err,
http.ErrServerClosed,
) {
slog.Error("http server error", "err", err)
return
}
slog.Info("stopped http server")
}()
wg.Add(1)
go func() {
<-ctx.Done()
ctx, cancel := context.WithTimeout(context.Background(), shutdownTimeout)
defer cancel()
if err := s.httpServer.Shutdown(ctx); err != nil { //nolint:contextcheck
slog.Error("http server shutdown", "err", err)
}
wg.Done()
}()
}
func (s *Server) Serve(ctx context.Context) error {
if err := s.Tail(parseFunc); err != nil {
return fmt.Errorf("starting tailing: %w", err)
}
wg := &sync.WaitGroup{}
s.http(ctx, wg)
wg.Wait()
return nil
}