Add '/metrics' HTTP endpoint with default prometheus metrics.

cmd/bots/internal/common/api/api.go

@@ -14,6 +14,7 @@ import (
 
 	"nodemon/cmd/bots/internal/common/messaging"
 	"nodemon/pkg/messaging/pair"
+	"nodemon/pkg/tools"
 )
 
 const (
@@ -25,6 +26,8 @@ type mwLog struct{ *zap.Logger }
 
 func (m mwLog) Print(v ...interface{}) { m.Sugar().Info(v...) }
 
+func (m mwLog) Println(v ...interface{}) { m.Sugar().Infoln(v...) }
+
 type BotAPI struct {
 	srv          *http.Server
 	requestChan  chan<- pair.Request
@@ -57,15 +60,16 @@ func NewBotAPI(
 	}))
 	r.Use(middleware.Recoverer)
 	r.Use(middleware.SetHeader("Content-Type", "application/json"))
-	r.Mount("/", a.routes())
+	r.Mount("/", a.routes(logger))
 	a.srv = &http.Server{Addr: bind, Handler: r, ReadHeaderTimeout: apiReadTimeout, ReadTimeout: apiReadTimeout}
 	return a, nil
 }
 
-func (a *BotAPI) routes() chi.Router {
+func (a *BotAPI) routes(logger *zap.Logger) chi.Router {
 	r := chi.NewRouter()
 	r.Get("/health", a.health)
 	r.Handle("/log/level", a.atom)
+	r.Handle("/metrics", tools.PrometheusHTTPMetricsHandler(mwLog{logger}))
 	return r
 }
 

go.mod

@@ -9,6 +9,7 @@ require (
 	github.com/hashicorp/vault/api/auth/userpass v0.5.0
 	github.com/pkg/errors v0.9.1
 	github.com/procyon-projects/chrono v1.1.2
+	github.com/prometheus/client_golang v1.17.0
 	github.com/stoewer/go-strcase v1.3.0
 	github.com/stretchr/testify v1.8.4
 	github.com/tidwall/buntdb v1.3.0
@@ -21,10 +22,12 @@ require (
 require (
 	filippo.io/edwards25519 v1.0.0 // indirect
 	github.com/Microsoft/go-winio v0.6.0 // indirect
+	github.com/beorn7/perks v1.0.1 // indirect
 	github.com/bits-and-blooms/bitset v1.8.0 // indirect
 	github.com/blang/semver/v4 v4.0.0 // indirect
 	github.com/btcsuite/btcd/btcec/v2 v2.3.2 // indirect
 	github.com/cenkalti/backoff/v3 v3.0.0 // indirect
+	github.com/cespare/xxhash/v2 v2.2.0 // indirect
 	github.com/consensys/bavard v0.1.13 // indirect
 	github.com/consensys/gnark v0.9.1 // indirect
 	github.com/consensys/gnark-crypto v0.12.2-0.20231013160410-1f65e75b6dfb // indirect
@@ -48,11 +51,15 @@ require (
 	github.com/jinzhu/copier v0.4.0 // indirect
 	github.com/mattn/go-colorable v0.1.13 // indirect
 	github.com/mattn/go-isatty v0.0.19 // indirect
+	github.com/matttproud/golang_protobuf_extensions v1.0.4 // indirect
 	github.com/mitchellh/go-homedir v1.1.0 // indirect
 	github.com/mitchellh/mapstructure v1.5.0 // indirect
 	github.com/mmcloughlin/addchain v0.4.0 // indirect
 	github.com/mr-tron/base58 v1.2.0 // indirect
 	github.com/pmezard/go-difflib v1.0.0 // indirect
+	github.com/prometheus/client_model v0.4.1-0.20230718164431-9a2bf3000d16 // indirect
+	github.com/prometheus/common v0.44.0 // indirect
+	github.com/prometheus/procfs v0.11.1 // indirect
 	github.com/rs/zerolog v1.30.0 // indirect
 	github.com/ryanuber/go-glob v1.0.0 // indirect
 	github.com/tidwall/btree v1.4.2 // indirect

go.sum

@@ -76,6 +76,7 @@ github.com/armon/go-radix v0.0.0-20180808171621-7fddfc383310/go.mod h1:ufUuZ+zHj
 github.com/armon/go-radix v1.0.0/go.mod h1:ufUuZ+zHj4x4TnLV4JWEpy2hxWSpsRywHrMgIH9cCH8=
 github.com/beorn7/perks v0.0.0-20180321164747-3a771d992973/go.mod h1:Dwedo/Wpr24TaqPxmxbtue+5NUziq4I4S80YR8gNf3Q=
 github.com/beorn7/perks v1.0.0/go.mod h1:KWe93zE9D1o94FZ5RNwFwVgaQK1VOXiVxmqh+CedLV8=
+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/bgentry/speakeasy v0.1.0/go.mod h1:+zsyZBPWlz7T6j88CTgSN5bM796AkVf0kBD4zp0CCIs=
 github.com/bits-and-blooms/bitset v1.8.0 h1:FD+XqgOZDUxxZ8hzoBFuV9+cGWY9CslN6d5MS5JVb4c=
@@ -92,6 +93,8 @@ github.com/cenkalti/backoff/v3 v3.0.0/go.mod h1:cIeZDE3IrqwwJl6VUwCN6trj1oXrTS4r
 github.com/census-instrumentation/opencensus-proto v0.2.1/go.mod h1:f6KPmirojxKA12rnyqOA5BBL4O983OfeGPqjHWSTneU=
 github.com/cespare/xxhash v1.1.0/go.mod h1:XrSqR1VqqWfGrhpAt58auRo0WTKS1nRRg3ghfAqPWnc=
 github.com/cespare/xxhash/v2 v2.1.1/go.mod h1:VGX0DQ3Q6kWi7AoAeZDth3/j3BFtOZR5XLFGgcrjCOs=
+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/chzyer/logex v1.1.10/go.mod h1:+Ywpsq7O8HXn0nuIou7OrIPyXbp3wmkHB+jjWRnGsAI=
 github.com/chzyer/readline v0.0.0-20180603132655-2972be24d48e/go.mod h1:nSuG5e5PlCu98SY8svDHJxuZscDgtXS6KTTbou5AhLI=
 github.com/chzyer/test v0.0.0-20180213035817-a1ea475d72b1/go.mod h1:Q3SI9o4m/ZMnBNeIyt5eFwwo7qiLfzFZmjNmxjkiQlU=
@@ -360,6 +363,8 @@ github.com/mattn/go-isatty v0.0.16/go.mod h1:kYGgaQfpe5nmfYZH+SKPsOc2e4SrIfOl2e/
 github.com/mattn/go-isatty v0.0.19 h1:JITubQf0MOLdlGRuRq+jtsDlekdYPia9ZFsB8h/APPA=
 github.com/mattn/go-isatty v0.0.19/go.mod h1:W+V8PltTTMOvKvAeJH7IuucS94S2C6jfK/D7dTCTo3Y=
 github.com/matttproud/golang_protobuf_extensions v1.0.1/go.mod h1:D8He9yQNgCq6Z5Ld7szi9bcBfOoFv/3dc6xSMkL2PC0=
+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/miekg/dns v1.1.26/go.mod h1:bPDLeHnStXmXAq1m/Ch/hvfNHr14JKNPMBo3VZKjuso=
 github.com/miekg/dns v1.1.41/go.mod h1:p6aan82bvRIyn+zDIv9xYNUpwa73JcSh9BKwknJysuI=
 github.com/mitchellh/cli v1.0.0/go.mod h1:hNIlj7HEI86fIcpObd7a0FcrxTWetlwJDGcceTlRvqc=
@@ -406,19 +411,27 @@ github.com/prometheus/client_golang v1.0.0/go.mod h1:db9x61etRT2tGnBNRi70OPL5Fsn
 github.com/prometheus/client_golang v1.4.0/go.mod h1:e9GMxYsXl05ICDXkRhurwBS4Q3OK1iX/F2sw+iXX5zU=
 github.com/prometheus/client_golang v1.7.1/go.mod h1:PY5Wy2awLA44sXw4AOSfFBetzPP4j5+D6mVACh+pe2M=
 github.com/prometheus/client_golang v1.11.1/go.mod h1:Z6t4BnS23TR94PD6BsDNk8yVqroYurpAkEiz0P2BEV0=
+github.com/prometheus/client_golang v1.17.0 h1:rl2sfwZMtSthVU752MqfjQozy7blglC+1SOtjMAMh+Q=
+github.com/prometheus/client_golang v1.17.0/go.mod h1:VeL+gMmOAxkS2IqfCq0ZmHSL+LjWfWDUmp1mBz9JgUY=
 github.com/prometheus/client_model v0.0.0-20180712105110-5c3871d89910/go.mod h1:MbSGuTsp3dbXC40dX6PRTWyKYBIrTGTE9sqQNg2J8bo=
 github.com/prometheus/client_model v0.0.0-20190129233127-fd36f4220a90/go.mod h1:xMI15A0UPsDsEKsMN9yxemIoYk6Tm2C1GtYGdfGttqA=
 github.com/prometheus/client_model v0.0.0-20190812154241-14fe0d1b01d4/go.mod h1:xMI15A0UPsDsEKsMN9yxemIoYk6Tm2C1GtYGdfGttqA=
 github.com/prometheus/client_model v0.2.0/go.mod h1:xMI15A0UPsDsEKsMN9yxemIoYk6Tm2C1GtYGdfGttqA=
+github.com/prometheus/client_model v0.4.1-0.20230718164431-9a2bf3000d16 h1:v7DLqVdK4VrYkVD5diGdl4sxJurKJEMnODWRJlxV9oM=
+github.com/prometheus/client_model v0.4.1-0.20230718164431-9a2bf3000d16/go.mod h1:oMQmHW1/JoDwqLtg57MGgP/Fb1CJEYF2imWWhWtMkYU=
 github.com/prometheus/common v0.4.1/go.mod h1:TNfzLD0ON7rHzMJeJkieUDPYmFC7Snx/y86RQel1bk4=
 github.com/prometheus/common v0.9.1/go.mod h1:yhUN8i9wzaXS3w1O07YhxHEBxD+W35wd8bs7vj7HSQ4=
 github.com/prometheus/common v0.10.0/go.mod h1:Tlit/dnDKsSWFlCLTWaA1cyBgKHSMdTB80sz/V91rCo=
 github.com/prometheus/common v0.26.0/go.mod h1:M7rCNAaPfAosfx8veZJCuw84e35h3Cfd9VFqTh1DIvc=
+github.com/prometheus/common v0.44.0 h1:+5BrQJwiBB9xsMygAB3TNvpQKOwlkc25LbISbrdOOfY=
+github.com/prometheus/common v0.44.0/go.mod h1:ofAIvZbQ1e/nugmZGz4/qCb9Ap1VoSTIO7x0VV9VvuY=
 github.com/prometheus/procfs v0.0.0-20181005140218-185b4288413d/go.mod h1:c3At6R/oaqEKCNdg8wHV1ftS6bRYblBhIjjI8uT2IGk=
 github.com/prometheus/procfs v0.0.2/go.mod h1:TjEm7ze935MbeOT/UhFTIMYKhuLP4wbCsTZCD3I8kEA=
 github.com/prometheus/procfs v0.0.8/go.mod h1:7Qr8sr6344vo1JqZ6HhLceV9o3AJ1Ff+GxbHq6oeK9A=
 github.com/prometheus/procfs v0.1.3/go.mod h1:lV6e/gmhEcM9IjHGsFOCxxuZ+z1YqCvr4OA4YeYWdaU=
 github.com/prometheus/procfs v0.6.0/go.mod h1:cz+aTbrPOrUb4q7XlbU9ygM+/jj0fzG6c1xBZuNvfVA=
+github.com/prometheus/procfs v0.11.1 h1:xRC8Iq1yyca5ypa9n1EZnWZkt7dwcoRPQwX/5gwaUuI=
+github.com/prometheus/procfs v0.11.1/go.mod h1:eesXgaPo1q7lBpVMoMy0ZOFTth9hBn4W/y0/p/ScXhY=
 github.com/rogpeppe/fastuuid v1.2.0/go.mod h1:jVj6XXZzXRy/MSR5jhDC/2q6DgLz+nrA6LYCDYWNEvQ=
 github.com/rogpeppe/go-internal v1.3.0/go.mod h1:M8bDsm7K2OlrFYOpmOWEs/qY81heoFRclV5y23lUDJ4=
 github.com/rogpeppe/go-internal v1.6.1/go.mod h1:xXDCJY+GAPziupqXw64V24skbSoqbTEfhy4qGm1nDQc=

pkg/api/api.go

@@ -15,6 +15,7 @@ import (
 	"nodemon/pkg/storing/events"
 	"nodemon/pkg/storing/nodes"
 	"nodemon/pkg/storing/specific"
+	"nodemon/pkg/tools"
 
 	"github.com/go-chi/chi"
 	"github.com/go-chi/chi/middleware"
@@ -41,6 +42,8 @@ type mwLog struct{ *zap.Logger }
 
 func (m mwLog) Print(v ...interface{}) { m.Sugar().Info(v...) }
 
+func (m mwLog) Println(v ...interface{}) { m.Sugar().Infoln(v...) }
+
 func NewAPI(
 	bind string,
 	nodesStorage nodes.Storage,
@@ -67,7 +70,7 @@ func NewAPI(
 	}))
 	r.Use(middleware.Recoverer)
 	r.Use(middleware.SetHeader("Content-Type", "application/json"))
-	r.Mount("/", a.routes())
+	r.Mount("/", a.routes(logger))
 	a.srv = &http.Server{Addr: bind, Handler: r, ReadHeaderTimeout: apiReadTimeout, ReadTimeout: apiReadTimeout}
 	return a, nil
 }
@@ -95,13 +98,14 @@ func (a *API) Shutdown() {
 	}
 }
 
-func (a *API) routes() chi.Router {
+func (a *API) routes(logger *zap.Logger) chi.Router {
 	r := chi.NewRouter()
 	r.Get("/nodes/all", a.nodes)
 	r.Get("/nodes/enabled", a.enabled)
 	r.Post("/nodes/specific/statements", a.specificNodesHandler)
 	r.Get("/health", a.health)
 	r.Handle("/log/level", a.atom)
+	r.Handle("/metrics", tools.PrometheusHTTPMetricsHandler(mwLog{logger}))
 	return r
 }
 

pkg/tools/metrics.go

@@ -0,0 +1,17 @@
+package tools
+
+import (
+	"net/http"
+
+	"github.com/prometheus/client_golang/prometheus"
+	"github.com/prometheus/client_golang/prometheus/promhttp"
+)
+
+func PrometheusHTTPMetricsHandler(logger promhttp.Logger) http.Handler {
+	return promhttp.InstrumentMetricHandler(
+		prometheus.DefaultRegisterer,
+		promhttp.HandlerFor(prometheus.DefaultGatherer, promhttp.HandlerOpts{
+			ErrorLog: logger,
+		}),
+	)
+}