SansanandClaude Opus 5.5
f79f51ea4c
Metrics are served on METRICS_PORT (default 2112, "off" to disable), never on the public port. Besides the Go runtime and process metrics this adds: - http_requests_total and http_request_duration_seconds per route pattern, from an Echo middleware. - musicserver_songs_requested_total and musicserver_songs_played_total by pick mode (random, low, classic). The mode is now stored with each queued song (migration 000006, not released yet). - Library size, sync duration, last successful sync, broken songs from the last full sync, and the database connection pool. Refs #35, #36, #37 Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
61 lines
1.6 KiB
Go
61 lines
1.6 KiB
Go
// Package metrics exposes Prometheus metrics: the Go runtime and process metrics that the
|
|
// default registry collects, HTTP request metrics and MusicServer's own metrics.
|
|
package metrics
|
|
|
|
import (
|
|
"context"
|
|
"errors"
|
|
"fmt"
|
|
"net"
|
|
"net/http"
|
|
"time"
|
|
|
|
"music-server/internal/logging"
|
|
|
|
"github.com/prometheus/client_golang/prometheus/promhttp"
|
|
"go.uber.org/zap"
|
|
)
|
|
|
|
// Server serves /metrics on a port of its own, so it is never reachable through the
|
|
// public port.
|
|
type Server struct {
|
|
httpServer *http.Server
|
|
}
|
|
|
|
// NewServer creates a metrics server for the given port.
|
|
func NewServer(port int) *Server {
|
|
mux := http.NewServeMux()
|
|
mux.Handle("GET /metrics", promhttp.Handler())
|
|
return &Server{httpServer: &http.Server{
|
|
Addr: fmt.Sprintf(":%d", port),
|
|
Handler: mux,
|
|
ReadHeaderTimeout: 5 * time.Second,
|
|
}}
|
|
}
|
|
|
|
// Handler returns the handler that serves /metrics.
|
|
func (s *Server) Handler() http.Handler {
|
|
return s.httpServer.Handler
|
|
}
|
|
|
|
// Start listens on the port and serves metrics in the background. It returns an error
|
|
// when the port cannot be opened.
|
|
func (s *Server) Start() error {
|
|
ln, err := net.Listen("tcp", s.httpServer.Addr)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
logging.GetLogger().Info("Metrics server starting", zap.String("address", s.httpServer.Addr))
|
|
go func() {
|
|
if err := s.httpServer.Serve(ln); !errors.Is(err, http.ErrServerClosed) {
|
|
logging.GetLogger().Error("Metrics server error", zap.Error(err))
|
|
}
|
|
}()
|
|
return nil
|
|
}
|
|
|
|
// Shutdown stops the metrics server.
|
|
func (s *Server) Shutdown(ctx context.Context) error {
|
|
return s.httpServer.Shutdown(ctx)
|
|
}
|