package metrics import ( "context" "net/http" "strconv" "strings" "time" "unicode/utf8" "github.com/containous/alice" gokitmetrics "github.com/go-kit/kit/metrics" "github.com/traefik/traefik/v2/pkg/log" "github.com/traefik/traefik/v2/pkg/metrics" "github.com/traefik/traefik/v2/pkg/middlewares" "github.com/traefik/traefik/v2/pkg/middlewares/retry" traefiktls "github.com/traefik/traefik/v2/pkg/tls" ) const ( protoHTTP = "http" protoSSE = "sse" protoWebsocket = "websocket" typeName = "Metrics" nameEntrypoint = "metrics-entrypoint" nameService = "metrics-service" ) type metricsMiddleware struct { next http.Handler reqsCounter gokitmetrics.Counter reqsTLSCounter gokitmetrics.Counter reqDurationHistogram metrics.ScalableHistogram openConnsGauge gokitmetrics.Gauge baseLabels []string } // NewEntryPointMiddleware creates a new metrics middleware for an Entrypoint. func NewEntryPointMiddleware(ctx context.Context, next http.Handler, registry metrics.Registry, entryPointName string) http.Handler { log.FromContext(middlewares.GetLoggerCtx(ctx, nameEntrypoint, typeName)).Debug("Creating middleware") return &metricsMiddleware{ next: next, reqsCounter: registry.EntryPointReqsCounter(), reqsTLSCounter: registry.EntryPointReqsTLSCounter(), reqDurationHistogram: registry.EntryPointReqDurationHistogram(), openConnsGauge: registry.EntryPointOpenConnsGauge(), baseLabels: []string{"entrypoint", entryPointName}, } } // NewRouterMiddleware creates a new metrics middleware for a Router. func NewRouterMiddleware(ctx context.Context, next http.Handler, registry metrics.Registry, routerName string, serviceName string) http.Handler { log.FromContext(middlewares.GetLoggerCtx(ctx, nameEntrypoint, typeName)).Debug("Creating middleware") return &metricsMiddleware{ next: next, reqsCounter: registry.RouterReqsCounter(), reqsTLSCounter: registry.RouterReqsTLSCounter(), reqDurationHistogram: registry.RouterReqDurationHistogram(), openConnsGauge: registry.RouterOpenConnsGauge(), baseLabels: []string{"router", routerName, "service", serviceName}, } } // NewServiceMiddleware creates a new metrics middleware for a Service. func NewServiceMiddleware(ctx context.Context, next http.Handler, registry metrics.Registry, serviceName string) http.Handler { log.FromContext(middlewares.GetLoggerCtx(ctx, nameService, typeName)).Debug("Creating middleware") return &metricsMiddleware{ next: next, reqsCounter: registry.ServiceReqsCounter(), reqsTLSCounter: registry.ServiceReqsTLSCounter(), reqDurationHistogram: registry.ServiceReqDurationHistogram(), openConnsGauge: registry.ServiceOpenConnsGauge(), baseLabels: []string{"service", serviceName}, } } // WrapEntryPointHandler Wraps metrics entrypoint to alice.Constructor. func WrapEntryPointHandler(ctx context.Context, registry metrics.Registry, entryPointName string) alice.Constructor { return func(next http.Handler) (http.Handler, error) { return NewEntryPointMiddleware(ctx, next, registry, entryPointName), nil } } // WrapRouterHandler Wraps metrics router to alice.Constructor. func WrapRouterHandler(ctx context.Context, registry metrics.Registry, routerName string, serviceName string) alice.Constructor { return func(next http.Handler) (http.Handler, error) { return NewRouterMiddleware(ctx, next, registry, routerName, serviceName), nil } } // WrapServiceHandler Wraps metrics service to alice.Constructor. func WrapServiceHandler(ctx context.Context, registry metrics.Registry, serviceName string) alice.Constructor { return func(next http.Handler) (http.Handler, error) { return NewServiceMiddleware(ctx, next, registry, serviceName), nil } } func (m *metricsMiddleware) ServeHTTP(rw http.ResponseWriter, req *http.Request) { var labels []string labels = append(labels, m.baseLabels...) labels = append(labels, "method", getMethod(req), "protocol", getRequestProtocol(req)) m.openConnsGauge.With(labels...).Add(1) defer m.openConnsGauge.With(labels...).Add(-1) // TLS metrics if req.TLS != nil { var tlsLabels []string tlsLabels = append(tlsLabels, m.baseLabels...) tlsLabels = append(tlsLabels, "tls_version", traefiktls.GetVersion(req.TLS), "tls_cipher", traefiktls.GetCipherName(req.TLS)) m.reqsTLSCounter.With(tlsLabels...).Add(1) } recorder := newResponseRecorder(rw) start := time.Now() m.next.ServeHTTP(recorder, req) labels = append(labels, "code", strconv.Itoa(recorder.getCode())) histograms := m.reqDurationHistogram.With(labels...) histograms.ObserveFromStart(start) m.reqsCounter.With(labels...).Add(1) } func getRequestProtocol(req *http.Request) string { switch { case isWebsocketRequest(req): return protoWebsocket case isSSERequest(req): return protoSSE default: return protoHTTP } } // isWebsocketRequest determines if the specified HTTP request is a websocket handshake request. func isWebsocketRequest(req *http.Request) bool { return containsHeader(req, "Connection", "upgrade") && containsHeader(req, "Upgrade", "websocket") } // isSSERequest determines if the specified HTTP request is a request for an event subscription. func isSSERequest(req *http.Request) bool { return containsHeader(req, "Accept", "text/event-stream") } func containsHeader(req *http.Request, name, value string) bool { items := strings.Split(req.Header.Get(name), ",") for _, item := range items { if value == strings.ToLower(strings.TrimSpace(item)) { return true } } return false } func getMethod(r *http.Request) string { if !utf8.ValidString(r.Method) { log.Warnf("Invalid HTTP method encoding: %s", r.Method) return "NON_UTF8_HTTP_METHOD" } return r.Method } type retryMetrics interface { ServiceRetriesCounter() gokitmetrics.Counter } // NewRetryListener instantiates a MetricsRetryListener with the given retryMetrics. func NewRetryListener(retryMetrics retryMetrics, serviceName string) retry.Listener { return &RetryListener{retryMetrics: retryMetrics, serviceName: serviceName} } // RetryListener is an implementation of the RetryListener interface to // record RequestMetrics about retry attempts. type RetryListener struct { retryMetrics retryMetrics serviceName string } // Retried tracks the retry in the RequestMetrics implementation. func (m *RetryListener) Retried(req *http.Request, attempt int) { m.retryMetrics.ServiceRetriesCounter().With("service", m.serviceName).Add(1) }