diff options
Diffstat (limited to 'vendor/github.com/prometheus/client_golang/prometheus/promhttp/instrument_server_test.go')
| -rw-r--r-- | vendor/github.com/prometheus/client_golang/prometheus/promhttp/instrument_server_test.go | 375 |
1 files changed, 375 insertions, 0 deletions
diff --git a/vendor/github.com/prometheus/client_golang/prometheus/promhttp/instrument_server_test.go b/vendor/github.com/prometheus/client_golang/prometheus/promhttp/instrument_server_test.go new file mode 100644 index 000000000..e9af63e04 --- /dev/null +++ b/vendor/github.com/prometheus/client_golang/prometheus/promhttp/instrument_server_test.go @@ -0,0 +1,375 @@ +// Copyright 2017 The Prometheus Authors +// Licensed under the Apache License, Version 2.0 (the "License"); +// you may not use this file except in compliance with the License. +// You may obtain a copy of the License at +// +// http://www.apache.org/licenses/LICENSE-2.0 +// +// Unless required by applicable law or agreed to in writing, software +// distributed under the License is distributed on an "AS IS" BASIS, +// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +// See the License for the specific language governing permissions and +// limitations under the License. + +package promhttp + +import ( + "io" + "log" + "net/http" + "net/http/httptest" + "testing" + + "github.com/prometheus/client_golang/prometheus" +) + +func TestLabelCheck(t *testing.T) { + scenarios := map[string]struct { + varLabels []string + constLabels []string + curriedLabels []string + ok bool + }{ + "empty": { + varLabels: []string{}, + constLabels: []string{}, + curriedLabels: []string{}, + ok: true, + }, + "code as single var label": { + varLabels: []string{"code"}, + constLabels: []string{}, + curriedLabels: []string{}, + ok: true, + }, + "method as single var label": { + varLabels: []string{"method"}, + constLabels: []string{}, + curriedLabels: []string{}, + ok: true, + }, + "cade and method as var labels": { + varLabels: []string{"method", "code"}, + constLabels: []string{}, + curriedLabels: []string{}, + ok: true, + }, + "valid case with all labels used": { + varLabels: []string{"code", "method"}, + constLabels: []string{"foo", "bar"}, + curriedLabels: []string{"dings", "bums"}, + ok: true, + }, + "unsupported var label": { + varLabels: []string{"foo"}, + constLabels: []string{}, + curriedLabels: []string{}, + ok: false, + }, + "mixed var labels": { + varLabels: []string{"method", "foo", "code"}, + constLabels: []string{}, + curriedLabels: []string{}, + ok: false, + }, + "unsupported var label but curried": { + varLabels: []string{}, + constLabels: []string{}, + curriedLabels: []string{"foo"}, + ok: true, + }, + "mixed var labels but unsupported curried": { + varLabels: []string{"code", "method"}, + constLabels: []string{}, + curriedLabels: []string{"foo"}, + ok: true, + }, + "supported label as const and curry": { + varLabels: []string{}, + constLabels: []string{"code"}, + curriedLabels: []string{"method"}, + ok: true, + }, + "supported label as const and curry with unsupported as var": { + varLabels: []string{"foo"}, + constLabels: []string{"code"}, + curriedLabels: []string{"method"}, + ok: false, + }, + } + + for name, sc := range scenarios { + t.Run(name, func(t *testing.T) { + constLabels := prometheus.Labels{} + for _, l := range sc.constLabels { + constLabels[l] = "dummy" + } + c := prometheus.NewCounterVec( + prometheus.CounterOpts{ + Name: "c", + Help: "c help", + ConstLabels: constLabels, + }, + append(sc.varLabels, sc.curriedLabels...), + ) + o := prometheus.ObserverVec(prometheus.NewHistogramVec( + prometheus.HistogramOpts{ + Name: "c", + Help: "c help", + ConstLabels: constLabels, + }, + append(sc.varLabels, sc.curriedLabels...), + )) + for _, l := range sc.curriedLabels { + c = c.MustCurryWith(prometheus.Labels{l: "dummy"}) + o = o.MustCurryWith(prometheus.Labels{l: "dummy"}) + } + + func() { + defer func() { + if err := recover(); err != nil { + if sc.ok { + t.Error("unexpected panic:", err) + } + } else if !sc.ok { + t.Error("expected panic") + } + }() + InstrumentHandlerCounter(c, nil) + }() + func() { + defer func() { + if err := recover(); err != nil { + if sc.ok { + t.Error("unexpected panic:", err) + } + } else if !sc.ok { + t.Error("expected panic") + } + }() + InstrumentHandlerDuration(o, nil) + }() + if sc.ok { + // Test if wantCode and wantMethod were detected correctly. + var wantCode, wantMethod bool + for _, l := range sc.varLabels { + if l == "code" { + wantCode = true + } + if l == "method" { + wantMethod = true + } + } + gotCode, gotMethod := checkLabels(c) + if gotCode != wantCode { + t.Errorf("wanted code=%t for counter, got code=%t", wantCode, gotCode) + } + if gotMethod != wantMethod { + t.Errorf("wanted method=%t for counter, got method=%t", wantMethod, gotMethod) + } + gotCode, gotMethod = checkLabels(o) + if gotCode != wantCode { + t.Errorf("wanted code=%t for observer, got code=%t", wantCode, gotCode) + } + if gotMethod != wantMethod { + t.Errorf("wanted method=%t for observer, got method=%t", wantMethod, gotMethod) + } + } + }) + } +} + +func TestMiddlewareAPI(t *testing.T) { + reg := prometheus.NewRegistry() + + inFlightGauge := prometheus.NewGauge(prometheus.GaugeOpts{ + Name: "in_flight_requests", + Help: "A gauge of requests currently being served by the wrapped handler.", + }) + + counter := prometheus.NewCounterVec( + prometheus.CounterOpts{ + Name: "api_requests_total", + Help: "A counter for requests to the wrapped handler.", + }, + []string{"code", "method"}, + ) + + histVec := prometheus.NewHistogramVec( + prometheus.HistogramOpts{ + Name: "response_duration_seconds", + Help: "A histogram of request latencies.", + Buckets: prometheus.DefBuckets, + ConstLabels: prometheus.Labels{"handler": "api"}, + }, + []string{"method"}, + ) + + writeHeaderVec := prometheus.NewHistogramVec( + prometheus.HistogramOpts{ + Name: "write_header_duration_seconds", + Help: "A histogram of time to first write latencies.", + Buckets: prometheus.DefBuckets, + ConstLabels: prometheus.Labels{"handler": "api"}, + }, + []string{}, + ) + + responseSize := prometheus.NewHistogramVec( + prometheus.HistogramOpts{ + Name: "push_request_size_bytes", + Help: "A histogram of request sizes for requests.", + Buckets: []float64{200, 500, 900, 1500}, + }, + []string{}, + ) + + handler := http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) { + w.Write([]byte("OK")) + }) + + reg.MustRegister(inFlightGauge, counter, histVec, responseSize, writeHeaderVec) + + chain := InstrumentHandlerInFlight(inFlightGauge, + InstrumentHandlerCounter(counter, + InstrumentHandlerDuration(histVec, + InstrumentHandlerTimeToWriteHeader(writeHeaderVec, + InstrumentHandlerResponseSize(responseSize, handler), + ), + ), + ), + ) + + r, _ := http.NewRequest("GET", "www.example.com", nil) + w := httptest.NewRecorder() + chain.ServeHTTP(w, r) +} + +func TestInstrumentTimeToFirstWrite(t *testing.T) { + var i int + dobs := &responseWriterDelegator{ + ResponseWriter: httptest.NewRecorder(), + observeWriteHeader: func(status int) { + i = status + }, + } + d := newDelegator(dobs, nil) + + d.WriteHeader(http.StatusOK) + + if i != http.StatusOK { + t.Fatalf("failed to execute observeWriteHeader") + } +} + +// testResponseWriter is an http.ResponseWriter that also implements +// http.CloseNotifier, http.Flusher, and io.ReaderFrom. +type testResponseWriter struct { + closeNotifyCalled, flushCalled, readFromCalled bool +} + +func (t *testResponseWriter) Header() http.Header { return nil } +func (t *testResponseWriter) Write([]byte) (int, error) { return 0, nil } +func (t *testResponseWriter) WriteHeader(int) {} +func (t *testResponseWriter) CloseNotify() <-chan bool { + t.closeNotifyCalled = true + return nil +} +func (t *testResponseWriter) Flush() { t.flushCalled = true } +func (t *testResponseWriter) ReadFrom(io.Reader) (int64, error) { + t.readFromCalled = true + return 0, nil +} + +func TestInterfaceUpgrade(t *testing.T) { + w := &testResponseWriter{} + d := newDelegator(w, nil) + d.(http.CloseNotifier).CloseNotify() + if !w.closeNotifyCalled { + t.Error("CloseNotify not called") + } + d.(http.Flusher).Flush() + if !w.flushCalled { + t.Error("Flush not called") + } + d.(io.ReaderFrom).ReadFrom(nil) + if !w.readFromCalled { + t.Error("ReadFrom not called") + } + if _, ok := d.(http.Hijacker); ok { + t.Error("delegator unexpectedly implements http.Hijacker") + } +} + +func ExampleInstrumentHandlerDuration() { + inFlightGauge := prometheus.NewGauge(prometheus.GaugeOpts{ + Name: "in_flight_requests", + Help: "A gauge of requests currently being served by the wrapped handler.", + }) + + counter := prometheus.NewCounterVec( + prometheus.CounterOpts{ + Name: "api_requests_total", + Help: "A counter for requests to the wrapped handler.", + }, + []string{"code", "method"}, + ) + + // duration is partitioned by the HTTP method and handler. It uses custom + // buckets based on the expected request duration. + duration := prometheus.NewHistogramVec( + prometheus.HistogramOpts{ + Name: "request_duration_seconds", + Help: "A histogram of latencies for requests.", + Buckets: []float64{.25, .5, 1, 2.5, 5, 10}, + }, + []string{"handler", "method"}, + ) + + // responseSize has no labels, making it a zero-dimensional + // ObserverVec. + responseSize := prometheus.NewHistogramVec( + prometheus.HistogramOpts{ + Name: "response_size_bytes", + Help: "A histogram of response sizes for requests.", + Buckets: []float64{200, 500, 900, 1500}, + }, + []string{}, + ) + + // Create the handlers that will be wrapped by the middleware. + pushHandler := http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) { + w.Write([]byte("Push")) + }) + pullHandler := http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) { + w.Write([]byte("Pull")) + }) + + // Register all of the metrics in the standard registry. + prometheus.MustRegister(inFlightGauge, counter, duration, responseSize) + + // Instrument the handlers with all the metrics, injecting the "handler" + // label by currying. + pushChain := InstrumentHandlerInFlight(inFlightGauge, + InstrumentHandlerDuration(duration.MustCurryWith(prometheus.Labels{"handler": "push"}), + InstrumentHandlerCounter(counter, + InstrumentHandlerResponseSize(responseSize, pushHandler), + ), + ), + ) + pullChain := InstrumentHandlerInFlight(inFlightGauge, + InstrumentHandlerDuration(duration.MustCurryWith(prometheus.Labels{"handler": "pull"}), + InstrumentHandlerCounter(counter, + InstrumentHandlerResponseSize(responseSize, pullHandler), + ), + ), + ) + + http.Handle("/metrics", Handler()) + http.Handle("/push", pushChain) + http.Handle("/pull", pullChain) + + if err := http.ListenAndServe(":3000", nil); err != nil { + log.Fatal(err) + } +} |