Add monitoring.

examples/prometheus_test.go

@@ -0,0 +1,96 @@
+package espresso_test
+
+import (
+	"fmt"
+	"io"
+	"net/http"
+	"net/http/httptest"
+
+	"github.com/googollee/go-espresso"
+	"github.com/googollee/go-espresso/monitoring/prometheus"
+)
+
+var mycounter = prometheus.NewCounter(prometheus.CounterOpts{
+	Name: "mycounter",
+})
+
+func AddCounter(ctx espresso.Context) error {
+	var num int
+	if err := ctx.Endpoint(http.MethodGet, "/inc/:num").
+		BindPath("num", &num).End(); err != nil {
+		return err
+	}
+
+	mycounter.Add(float64(num))
+
+	ctx.ResponseWriter().WriteHeader(http.StatusNoContent)
+	return nil
+}
+
+func LaunchWithPrometheus() (addr string, cancel func()) {
+	server, _ := espresso.New(prometheus.New("/metrics"))
+
+	server.HandleFunc(AddCounter)
+
+	httpSvr := httptest.NewServer(server)
+	addr = httpSvr.URL
+	cancel = func() {
+		httpSvr.Close()
+	}
+
+	return
+}
+
+func ExampleMonitoringWithPrometheus() {
+	addr, cancel := LaunchWithPrometheus()
+	defer cancel()
+
+	{
+		resp, err := http.Get(addr + "/metrics")
+		if err != nil {
+			panic(err)
+		}
+
+		body, _ := io.ReadAll(resp.Body)
+		resp.Body.Close()
+
+		fmt.Println(resp.StatusCode, resp.Header.Get("Content-Type"), string(body))
+	}
+
+	{
+		resp, err := http.Get(addr + "/inc/100")
+		if err != nil {
+			panic(err)
+		}
+		resp.Body.Close()
+	}
+
+	{
+		resp, err := http.Get(addr + "/metrics")
+		if err != nil {
+			panic(err)
+		}
+
+		body, _ := io.ReadAll(resp.Body)
+		resp.Body.Close()
+
+		fmt.Println(resp.StatusCode, resp.Header.Get("Content-Type"), string(body))
+	}
+
+	// Output:
+	// 200 text/plain; version=0.0.4; charset=utf-8 # HELP mycounter
+	// # TYPE mycounter counter
+	// mycounter 0
+	// # HELP promhttp_metric_handler_errors_total Total number of internal errors encountered by the promhttp metric handler.
+	// # TYPE promhttp_metric_handler_errors_total counter
+	// promhttp_metric_handler_errors_total{cause="encoding"} 0
+	// promhttp_metric_handler_errors_total{cause="gathering"} 0
+
+	// 200 text/plain; version=0.0.4; charset=utf-8 # HELP mycounter
+	// # TYPE mycounter counter
+	// mycounter 100
+	// # HELP promhttp_metric_handler_errors_total Total number of internal errors encountered by the promhttp metric handler.
+	// # TYPE promhttp_metric_handler_errors_total counter
+	// promhttp_metric_handler_errors_total{cause="encoding"} 0
+	// promhttp_metric_handler_errors_total{cause="gathering"} 0
+}

go.mod

@@ -3,9 +3,21 @@ module github.com/googollee/go-espresso
 go 1.20
 
 require (
-	github.com/google/go-cmp v0.5.8
+	github.com/google/go-cmp v0.5.9
 	github.com/julienschmidt/httprouter v1.3.0
 	golang.org/x/exp v0.0.0-20230801115018-d63ba01acd4b
 )
 
-require github.com/timewasted/go-accept-headers v0.0.0-20130320203746-c78f304b1b09 // indirect
+require (
+	github.com/beorn7/perks v1.0.1 // indirect
+	github.com/cespare/xxhash/v2 v2.2.0 // indirect
+	github.com/golang/protobuf v1.5.3 // indirect
+	github.com/matttproud/golang_protobuf_extensions v1.0.4 // indirect
+	github.com/prometheus/client_golang v1.16.0 // indirect
+	github.com/prometheus/client_model v0.3.0 // indirect
+	github.com/prometheus/common v0.42.0 // indirect
+	github.com/prometheus/procfs v0.10.1 // indirect
+	github.com/timewasted/go-accept-headers v0.0.0-20130320203746-c78f304b1b09 // indirect
+	golang.org/x/sys v0.8.0 // indirect
+	google.golang.org/protobuf v1.30.0 // indirect
+)

go.sum

@@ -1,10 +1,39 @@
+github.com/beorn7/perks v1.0.1 h1:VlbKKnNfV8bJzeqoa4cOKqO6bYr3WgKZxO8Z16+hsOM=
+github.com/beorn7/perks v1.0.1/go.mod h1:G2ZrVWU2WbWT9wwq4/hrbKbnv/1ERSJQ0ibhJ6rlkpw=
+github.com/cespare/xxhash/v2 v2.2.0 h1:DC2CZ1Ep5Y4k3ZQ899DldepgrayRUGE6BBZ/cd9Cj44=
+github.com/cespare/xxhash/v2 v2.2.0/go.mod h1:VGX0DQ3Q6kWi7AoAeZDth3/j3BFtOZR5XLFGgcrjCOs=
+github.com/golang/protobuf v1.2.0/go.mod h1:6lQm79b+lXiMfvg/cZm0SGofjICqVBUtrP5yJMmIC1U=
+github.com/golang/protobuf v1.3.5/go.mod h1:6O5/vntMXwX2lRkT1hjjk0nAC1IDOTvTlVgjlRvqsdk=
+github.com/golang/protobuf v1.5.0/go.mod h1:FsONVRAS9T7sI+LIUmWTfcYkHO4aIWwzhcaSAoJOfIk=
+github.com/golang/protobuf v1.5.3 h1:KhyjKVUg7Usr/dYsdSqoFveMYd5ko72D+zANwlG1mmg=
+github.com/golang/protobuf v1.5.3/go.mod h1:XVQd3VNwM+JqD3oG2Ue2ip4fOMUkwXdXDdiuN0vRsmY=
+github.com/google/go-cmp v0.5.5/go.mod h1:v8dTdLbMG2kIc/vJvl+f65V22dbkXbowE6jgT/gNBxE=
 github.com/google/go-cmp v0.5.8 h1:e6P7q2lk1O+qJJb4BtCQXlK8vWEO8V1ZeuEdJNOqZyg=
 github.com/google/go-cmp v0.5.8/go.mod h1:17dUlkBOakJ0+DkrSSNjCkIjxS6bF9zb3elmeNGIjoY=
+github.com/google/go-cmp v0.5.9/go.mod h1:17dUlkBOakJ0+DkrSSNjCkIjxS6bF9zb3elmeNGIjoY=
 github.com/julienschmidt/httprouter v1.3.0 h1:U0609e9tgbseu3rBINet9P48AI/D3oJs4dN7jwJOQ1U=
 github.com/julienschmidt/httprouter v1.3.0/go.mod h1:JR6WtHb+2LUe8TCKY3cZOxFyyO8IZAc4RVcycCCAKdM=
+github.com/matttproud/golang_protobuf_extensions v1.0.4 h1:mmDVorXM7PCGKw94cs5zkfA9PSy5pEvNWRP0ET0TIVo=
+github.com/matttproud/golang_protobuf_extensions v1.0.4/go.mod h1:BSXmuO+STAnVfrANrmjBb36TMTDstsz7MSK+HVaYKv4=
+github.com/prometheus/client_golang v1.16.0 h1:yk/hx9hDbrGHovbci4BY+pRMfSuuat626eFsHb7tmT8=
+github.com/prometheus/client_golang v1.16.0/go.mod h1:Zsulrv/L9oM40tJ7T815tM89lFEugiJ9HzIqaAx4LKc=
+github.com/prometheus/client_model v0.3.0 h1:UBgGFHqYdG/TPFD1B1ogZywDqEkwp3fBMvqdiQ7Xew4=
+github.com/prometheus/client_model v0.3.0/go.mod h1:LDGWKZIo7rky3hgvBe+caln+Dr3dPggB5dvjtD7w9+w=
+github.com/prometheus/common v0.42.0 h1:EKsfXEYo4JpWMHH5cg+KOUWeuJSov1Id8zGR8eeI1YM=
+github.com/prometheus/common v0.42.0/go.mod h1:xBwqVerjNdUDjgODMpudtOMwlOwf2SaTr1yjz4b7Zbc=
+github.com/prometheus/procfs v0.10.1 h1:kYK1Va/YMlutzCGazswoHKo//tZVlFpKYh+PymziUAg=
+github.com/prometheus/procfs v0.10.1/go.mod h1:nwNm2aOCAYw8uTR/9bWRREkZFxAUcWzPHWJq+XBB/FM=
 github.com/timewasted/go-accept-headers v0.0.0-20130320203746-c78f304b1b09 h1:QVxbx5l/0pzciWYOynixQMtUhPYC3YKD6EcUlOsgGqw=
 github.com/timewasted/go-accept-headers v0.0.0-20130320203746-c78f304b1b09/go.mod h1:Uy/Rnv5WKuOO+PuDhuYLEpUiiKIZtss3z519uk67aF0=
 golang.org/x/exp v0.0.0-20230522175609-2e198f4a06a1 h1:k/i9J1pBpvlfR+9QsetwPyERsqu1GIbi967PQMq3Ivc=
 golang.org/x/exp v0.0.0-20230522175609-2e198f4a06a1/go.mod h1:V1LtkGg67GoY2N1AnLN78QLrzxkLyJw7RJb1gzOOz9w=
 golang.org/x/exp v0.0.0-20230801115018-d63ba01acd4b h1:r+vk0EmXNmekl0S0BascoeeoHk/L7wmaW2QF90K+kYI=
 golang.org/x/exp v0.0.0-20230801115018-d63ba01acd4b/go.mod h1:FXUEEKJgO7OQYeo8N01OfiKP8RXMtf6e8aTskBGqWdc=
+golang.org/x/sync v0.0.0-20181221193216-37e7f081c4d4/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
+golang.org/x/sys v0.8.0 h1:EBmGv8NaZBZTWvrbjNoL6HVt+IVy3QDQpJs7VRIw3tU=
+golang.org/x/sys v0.8.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
+golang.org/x/xerrors v0.0.0-20191204190536-9bdfabe68543/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
+google.golang.org/protobuf v1.26.0-rc.1/go.mod h1:jlhhOSvTdKEhbULTjvd4ARK9grFBp09yW+WbY/TyQbw=
+google.golang.org/protobuf v1.26.0/go.mod h1:9q0QmTI4eRPtz6boOQmLYwt+qCgq0jsYwAQnmE0givc=
+google.golang.org/protobuf v1.30.0 h1:kPPoIgf3TsEvrm0PFe15JQ+570QVxYzEvvHqChK+cng=
+google.golang.org/protobuf v1.30.0/go.mod h1:HV8QOd/L58Z+nl8r43ehVNZIU/HEI6OcFqwMG9pJV4I=

monitoring/prometheus/metric.go

@@ -0,0 +1,106 @@
+package prometheus
+
+import (
+	"net/http"
+
+	"github.com/googollee/go-espresso"
+	"github.com/prometheus/client_golang/prometheus"
+	"github.com/prometheus/client_golang/prometheus/promhttp"
+)
+
+var DefaultRegistry = prometheus.NewRegistry()
+
+type GaugeOpts = prometheus.GaugeOpts
+
+func NewGauge(opt GaugeOpts) prometheus.Gauge {
+	ret := prometheus.NewGauge(opt)
+	DefaultRegistry.MustRegister(ret)
+	return ret
+}
+
+func NewGaugeFunc(opt GaugeOpts, fn func() float64) prometheus.GaugeFunc {
+	ret := prometheus.NewGaugeFunc(opt, fn)
+	DefaultRegistry.MustRegister(ret)
+	return ret
+}
+
+func NewGaugeVec(opt GaugeOpts, labels []string) *prometheus.GaugeVec {
+	ret := prometheus.NewGaugeVec(opt, labels)
+	DefaultRegistry.MustRegister(ret)
+	return ret
+}
+
+type CounterOpts = prometheus.CounterOpts
+
+func NewCounter(opt CounterOpts) prometheus.Counter {
+	ret := prometheus.NewCounter(opt)
+	DefaultRegistry.MustRegister(ret)
+	return ret
+}
+
+func NewCounterFunc(opt CounterOpts, fn func() float64) prometheus.CounterFunc {
+	ret := prometheus.NewCounterFunc(opt, fn)
+	DefaultRegistry.MustRegister(ret)
+	return ret
+}
+
+func NewCounterVec(opt CounterOpts, labels []string) *prometheus.CounterVec {
+	ret := prometheus.NewCounterVec(opt, labels)
+	DefaultRegistry.MustRegister(ret)
+	return ret
+}
+
+type SummaryOpts = prometheus.SummaryOpts
+
+func NewSummary(opt SummaryOpts) prometheus.Summary {
+	ret := prometheus.NewSummary(opt)
+	DefaultRegistry.MustRegister(ret)
+	return ret
+}
+
+func NewSummaryVec(opt SummaryOpts, labels []string) *prometheus.SummaryVec {
+	ret := prometheus.NewSummaryVec(opt, labels)
+	DefaultRegistry.MustRegister(ret)
+	return ret
+}
+
+type HistogramOpts = prometheus.HistogramOpts
+
+func NewHistogram(opt HistogramOpts) prometheus.Histogram {
+	ret := prometheus.NewHistogram(opt)
+	DefaultRegistry.MustRegister(ret)
+	return ret
+}
+
+func NewHistogramVec(opt HistogramOpts, labels []string) *prometheus.HistogramVec {
+	ret := prometheus.NewHistogramVec(opt, labels)
+	DefaultRegistry.MustRegister(ret)
+	return ret
+}
+
+type UntypedOpts = prometheus.UntypedOpts
+
+func NewUntypedFunc(opt UntypedOpts, fn func() float64) prometheus.UntypedFunc {
+	ret := prometheus.NewUntypedFunc(opt, fn)
+	DefaultRegistry.MustRegister(ret)
+	return ret
+}
+
+func New(path string) espresso.ServerOption {
+	handler := promhttp.HandlerFor(DefaultRegistry, promhttp.HandlerOpts{
+		Registry: DefaultRegistry,
+	})
+
+	return func(s *espresso.Server) error {
+		s.HandleFunc(func(ctx espresso.Context) error {
+			if err := ctx.Endpoint(http.MethodGet, path).End(); err != nil {
+				return err
+			}
+
+			handler.ServeHTTP(ctx.ResponseWriter(), ctx.Request())
+			return nil
+		})
+
+		return nil
+	}
+}