Add prometheus metrics

internal/metrics/metrics.go

@@ -0,0 +1,46 @@
+package metrics
+
+import (
+	"github.com/prometheus/client_golang/prometheus"
+	"github.com/prometheus/client_golang/prometheus/promauto"
+)
+
+var (
+	WorkerJobCounter = promauto.NewCounterVec(
+		prometheus.CounterOpts{
+			Name: "transcriber_worker_job_count",
+			Help: "Count of jobs handled by each worker",
+		},
+		[]string{"name", "error"},
+	)
+
+	// Размер принятых на обработку файлов (в байтах)
+	InputFileSizeHistogram = promauto.NewHistogramVec(
+		prometheus.HistogramOpts{
+			Name:    "transcriber_input_file_size_bytes",
+			Help:    "Size of input files received for processing",
+			Buckets: []float64{1024, 10240, 102400, 1048576, 10485760, 104857600, 1073741824}, // 1KB, 10KB, 100KB, 1MB, 10MB, 100MB, 1GB
+		},
+		[]string{"file_extension"},
+	)
+
+	// Время конвертации файлов (в секундах)
+	ConversionDurationHistogram = promauto.NewHistogramVec(
+		prometheus.HistogramOpts{
+			Name:    "transcriber_conversion_duration_seconds",
+			Help:    "Time taken to convert audio files",
+			Buckets: []float64{0.1, 0.5, 1, 5, 10, 30, 60, 120, 300}, // 0.1s, 0.5s, 1s, 5s, 10s, 30s, 1m, 2m, 5m
+		},
+		[]string{"source_format", "target_format", "error"},
+	)
+
+	// Размер файла после конвертации (в байтах)
+	OutputFileSizeHistogram = promauto.NewHistogramVec(
+		prometheus.HistogramOpts{
+			Name:    "transcriber_output_file_size_bytes",
+			Help:    "Size of files after conversion",
+			Buckets: []float64{1024, 10240, 102400, 1048576, 10485760, 104857600, 1073741824}, // 1KB, 10KB, 100KB, 1MB, 10MB, 100MB, 1GB
+		},
+		[]string{"format"},
+	)
+)