package metrics
import (
"context"
"fmt"
"net/http"
"time"
"github.com/containers/kubernetes-mcp-server/pkg/config"
"k8s.io/klog/v2"
)
// Config contains configuration for the metrics system.
type Config struct {
TracerName string
ServiceName string
ServiceVersion string
// Telemetry is the optional telemetry configuration.
// If nil, env vars will be used for OTLP configuration.
Telemetry *config.TelemetryConfig
}
// Metrics coordinates multiple metric collectors.
// It implements the Collector interface and fans out calls to all registered collectors.
type Metrics struct {
collectors []Collector
stats *OtelStatsCollector
}
// New creates a new Metrics instance with configured collectors.
// If OTEL_EXPORTER_OTLP_ENDPOINT is set, metrics will also be exported to OTLP.
func New(cfg Config) (*Metrics, error) {
m := &Metrics{
collectors: []Collector{},
}
// Stats collector - always enabled for /stats endpoint
// Also exports to OTLP if OTEL_EXPORTER_OTLP_ENDPOINT is set or Telemetry config is provided
stats, err := NewOtelStatsCollectorWithConfig(CollectorConfig{
MeterName: cfg.TracerName,
ServiceName: cfg.ServiceName,
ServiceVersion: cfg.ServiceVersion,
Telemetry: cfg.Telemetry,
})
if err != nil {
return nil, fmt.Errorf("failed to create stats collector: %w", err)
}
m.stats = stats
m.collectors = append(m.collectors, m.stats)
klog.V(1).Info("Stats collector enabled")
return m, nil
}
// RecordToolCall implements the Collector interface.
// It fans out the call to all registered collectors.
func (m *Metrics) RecordToolCall(ctx context.Context, name string, duration time.Duration, err error) {
for _, c := range m.collectors {
c.RecordToolCall(ctx, name, duration, err)
}
}
// RecordHTTPRequest implements the Collector interface.
// It fans out the call to all registered collectors.
func (m *Metrics) RecordHTTPRequest(ctx context.Context, method, path string, statusCode int, duration time.Duration) {
for _, c := range m.collectors {
c.RecordHTTPRequest(ctx, method, path, statusCode, duration)
}
}
// GetStats returns the current statistics from the StatsCollector.
// This is used by the /stats HTTP endpoint.
func (m *Metrics) GetStats() *Statistics {
return m.stats.GetStats()
}
// Shutdown gracefully shuts down the metrics system, flushing any pending metrics.
func (m *Metrics) Shutdown(ctx context.Context) error {
return m.stats.Shutdown(ctx)
}
// PrometheusHandler returns the HTTP handler for the /metrics endpoint.
// This handler serves metrics in Prometheus text format
func (m *Metrics) PrometheusHandler() http.Handler {
return m.stats.PrometheusHandler()
}
