feat: otel metrics endpoint (#13)

go.mod

@@ -9,22 +9,36 @@ require (
 	github.com/golang/mock v1.6.0
 	github.com/gorilla/mux v1.8.0
 	github.com/joho/godotenv v1.5.1
+	github.com/lib/pq v1.10.7
 	github.com/ory/dockertest/v3 v3.9.1
+	github.com/phayes/freeport v0.0.0-20220201140144-74d24b5ae9f5
+	github.com/prometheus/client_golang v1.14.0
+	github.com/prometheus/client_model v0.3.0
+	github.com/prometheus/common v0.42.0
+	github.com/spf13/cast v1.5.0
 	github.com/spf13/viper v1.15.0
 	github.com/stretchr/testify v1.8.2
+	github.com/zenizh/go-capturer v0.0.0-20211219060012-52ea6c8fed04
 	go.opentelemetry.io/otel v1.14.0
 	go.opentelemetry.io/otel/exporters/otlp/otlpmetric/otlpmetricgrpc v0.37.0
 	go.opentelemetry.io/otel/exporters/otlp/otlptrace/otlptracegrpc v1.14.0
 	go.opentelemetry.io/otel/metric v0.37.0
 	go.opentelemetry.io/otel/sdk v1.14.0
 	go.opentelemetry.io/otel/sdk/metric v0.37.0
+	go.uber.org/zap v1.24.0
 	golang.org/x/exp v0.0.0-20230310171629-522b1b587ee0
+	golang.org/x/sync v0.1.0
+	google.golang.org/protobuf v1.30.0
+	gopkg.in/alexcesaro/statsd.v2 v2.0.0
+	gopkg.in/natefinch/lumberjack.v2 v2.2.1
 )
 
 require (
 	github.com/Azure/go-ansiterm v0.0.0-20210617225240-d185dfc1b5a1 // indirect
 	github.com/Microsoft/go-winio v0.5.2 // indirect
 	github.com/Nvveen/Gotty v0.0.0-20120604004816-cd527374f1e5 // indirect
+	github.com/beorn7/perks v1.0.1 // indirect
+	github.com/cespare/xxhash/v2 v2.2.0 // indirect
 	github.com/containerd/continuity v0.3.0 // indirect
 	github.com/davecgh/go-spew v1.1.1 // indirect
 	github.com/docker/cli v20.10.14+incompatible // indirect
@@ -39,7 +53,6 @@ require (
 	github.com/grpc-ecosystem/grpc-gateway/v2 v2.7.0 // indirect
 	github.com/hashicorp/hcl v1.0.0 // indirect
 	github.com/imdario/mergo v0.3.12 // indirect
-	github.com/lib/pq v1.10.7
 	github.com/magiconair/properties v1.8.7 // indirect
 	github.com/matttproud/golang_protobuf_extensions v1.0.4 // indirect
 	github.com/mitchellh/mapstructure v1.5.0 // indirect
@@ -48,39 +61,30 @@ require (
 	github.com/opencontainers/image-spec v1.1.0-rc2 // indirect
 	github.com/opencontainers/runc v1.1.4 // indirect
 	github.com/pelletier/go-toml/v2 v2.0.6 // indirect
-	github.com/phayes/freeport v0.0.0-20220201140144-74d24b5ae9f5
 	github.com/pkg/errors v0.9.1 // indirect
 	github.com/pmezard/go-difflib v1.0.0 // indirect
-	github.com/prometheus/client_model v0.3.0
-	github.com/prometheus/common v0.42.0
+	github.com/prometheus/procfs v0.8.0 // indirect
 	github.com/sirupsen/logrus v1.9.0 // indirect
 	github.com/spf13/afero v1.9.3 // indirect
-	github.com/spf13/cast v1.5.0
 	github.com/spf13/jwalterweatherman v1.1.0 // indirect
 	github.com/spf13/pflag v1.0.5 // indirect
 	github.com/subosito/gotenv v1.4.2 // indirect
 	github.com/xeipuuv/gojsonpointer v0.0.0-20180127040702-4e3ac2762d5f // indirect
 	github.com/xeipuuv/gojsonreference v0.0.0-20180127040603-bd5ef7bd5415 // indirect
 	github.com/xeipuuv/gojsonschema v1.2.0 // indirect
-	github.com/zenizh/go-capturer v0.0.0-20211219060012-52ea6c8fed04
 	go.opentelemetry.io/otel/exporters/otlp/internal/retry v1.14.0 // indirect
 	go.opentelemetry.io/otel/exporters/otlp/otlpmetric v0.37.0 // indirect
 	go.opentelemetry.io/otel/exporters/otlp/otlptrace v1.14.0 // indirect
 	go.opentelemetry.io/otel/trace v1.14.0 // indirect
 	go.opentelemetry.io/proto/otlp v0.19.0 // indirect
 	go.uber.org/atomic v1.10.0 // indirect
 	go.uber.org/multierr v1.8.0 // indirect
-	go.uber.org/zap v1.24.0
 	golang.org/x/net v0.7.0 // indirect
-	golang.org/x/sync v0.1.0
-	golang.org/x/sys v0.5.0 // indirect
+	golang.org/x/sys v0.6.0 // indirect
 	golang.org/x/text v0.7.0 // indirect
 	google.golang.org/genproto v0.0.0-20230110181048-76db0878b65f // indirect
 	google.golang.org/grpc v1.53.0 // indirect
-	google.golang.org/protobuf v1.28.1 // indirect
-	gopkg.in/alexcesaro/statsd.v2 v2.0.0
 	gopkg.in/ini.v1 v1.67.0 // indirect
-	gopkg.in/natefinch/lumberjack.v2 v2.2.1
 	gopkg.in/yaml.v2 v2.4.0 // indirect
 	gopkg.in/yaml.v3 v3.0.1 // indirect
 )

go.sum

@@ -47,11 +47,15 @@ github.com/Nvveen/Gotty v0.0.0-20120604004816-cd527374f1e5/go.mod h1:lmUJ/7eu/Q8
 github.com/OneOfOne/xxhash v1.2.2/go.mod h1:HSdplMjZKSmBqAxg5vPj2TmRDmfkzw+cTzAElWljhcU=
 github.com/antihax/optional v1.0.0/go.mod h1:uupD/76wgC+ih3iEmQUL+0Ugr19nfwCT1kdvxnR2qWY=
 github.com/benbjohnson/clock v1.1.0 h1:Q92kusRqC1XV2MjkWETPvjJVqKetz1OzxZB7mHJLju8=
+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/cenkalti/backoff/v4 v4.2.0 h1:HN5dHm3WBOgndBH6E8V0q2jIYIR3s9yglV8k/+MN3u4=
 github.com/cenkalti/backoff/v4 v4.2.0/go.mod h1:Y3VNntkOUPxTVeUxJ/G5vcM//AlwfmyYozVcomhLiZE=
 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/checkpoint-restore/go-criu/v5 v5.3.0/go.mod h1:E/eQpaFtUKGOOSEBZgmKAcn+zUUwWxqcaKZlF54wK8E=
 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=
@@ -238,11 +242,15 @@ github.com/pkg/errors v0.9.1/go.mod h1:bwawxfHBFNV+L2hUp1rHADufV3IMtnDRdf1r5NINE
 github.com/pkg/sftp v1.13.1/go.mod h1:3HaPG6Dq1ILlpPZRO0HVMrsydcdLt6HRDccSgb87qRg=
 github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
 github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
+github.com/prometheus/client_golang v1.14.0 h1:nJdhIvne2eSX/XRAFV9PcvFFRbrjbcTUj0VP62TMhnw=
+github.com/prometheus/client_golang v1.14.0/go.mod h1:8vpkKitgIVNcqrRBWh1C4TIUQgYNtG/XQE4E/Zae36Y=
 github.com/prometheus/client_model v0.0.0-20190812154241-14fe0d1b01d4/go.mod h1:xMI15A0UPsDsEKsMN9yxemIoYk6Tm2C1GtYGdfGttqA=
 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 v0.8.0 h1:ODq8ZFEaYeCaZOJlZZdJA2AbQR98dSHSM1KW/You5mo=
+github.com/prometheus/procfs v0.8.0/go.mod h1:z7EfXMXOkbkqb9IINtpCn86r/to3BnA0uaxHdg830/4=
 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 h1:/FiVV8dS/e+YqF2JvO3yXRFbBLTIuSDkuC7aBOAvL+k=
@@ -480,8 +488,8 @@ golang.org/x/sys v0.0.0-20211025201205-69cdffdb9359/go.mod h1:oPkhp1MJrh7nUepCBc
 golang.org/x/sys v0.0.0-20211116061358-0a5406a5449c/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/sys v0.0.0-20220715151400-c0bba94af5f8/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/sys v0.0.0-20220908164124-27713097b956/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
-golang.org/x/sys v0.5.0 h1:MUK/U/4lj1t1oPg0HfuXDN/Z1wv31ZJ/YcPiGccS4DU=
-golang.org/x/sys v0.5.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
+golang.org/x/sys v0.6.0 h1:MVltZSvRTcU2ljQOhs94SXPftV6DCNnZViHeQps87pQ=
+golang.org/x/sys v0.6.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/term v0.0.0-20201126162022-7de9c90e9dd1/go.mod h1:bj7SfCRtBDWHUb9snDiAeCFNEtKQo2Wmx5Cou7ajbmo=
 golang.org/x/text v0.0.0-20170915032832-14c0d48ead0c/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
 golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
@@ -651,8 +659,8 @@ google.golang.org/protobuf v1.25.0/go.mod h1:9JNX74DMeImyA3h4bdi1ymwjUzf21/xIlba
 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 v1.27.1/go.mod h1:9q0QmTI4eRPtz6boOQmLYwt+qCgq0jsYwAQnmE0givc=
-google.golang.org/protobuf v1.28.1 h1:d0NfwRgPtno5B1Wa6L2DAG+KivqkdutMf1UhdNx175w=
-google.golang.org/protobuf v1.28.1/go.mod h1:HV8QOd/L58Z+nl8r43ehVNZIU/HEI6OcFqwMG9pJV4I=
+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=
 gopkg.in/alexcesaro/statsd.v2 v2.0.0 h1:FXkZSCZIH17vLCO5sO2UucTHsH9pc+17F6pl3JVCwMc=
 gopkg.in/alexcesaro/statsd.v2 v2.0.0/go.mod h1:i0ubccKGzBVNBpdGV5MocxyA/XlLUJzA7SLonnE4drU=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=

stats/internal/otel/options.go

@@ -3,7 +3,7 @@ package otel
 import (
 	"time"
 
-	"go.opentelemetry.io/otel/exporters/otlp/otlpmetric/otlpmetricgrpc"
+	"github.com/prometheus/client_golang/prometheus"
 	"go.opentelemetry.io/otel/propagation"
 	"go.opentelemetry.io/otel/sdk/instrumentation"
 	sdkmetric "go.opentelemetry.io/otel/sdk/metric"
@@ -65,9 +65,8 @@ func WithGlobalTracerProvider() TracerProviderOption {
 }
 
 // WithMeterProvider allows to set the meter provider and specify if it should be the global one plus other options.
-func WithMeterProvider(endpoint string, opts ...MeterProviderOption) Option {
+func WithMeterProvider(opts ...MeterProviderOption) Option {
 	return func(c *config) {
-		c.metricsEndpoint = endpoint
 		c.meterProviderConfig.enabled = true
 		for _, opt := range opts {
 			opt(&c.meterProviderConfig)
@@ -82,6 +81,13 @@ func WithGlobalMeterProvider() MeterProviderOption {
 	}
 }
 
+// WithGRPCMeterProvider allows to set the meter provider to use GRPC
+func WithGRPCMeterProvider(grpcEndpoint string) MeterProviderOption {
+	return func(c *meterProviderConfig) {
+		c.grpcEndpoint = &grpcEndpoint
+	}
+}
+
 // WithMeterProviderExportsInterval configures the intervening time between exports (if less than or equal to zero,
 // 60 seconds is used)
 func WithMeterProviderExportsInterval(interval time.Duration) MeterProviderOption {
@@ -90,25 +96,30 @@ func WithMeterProviderExportsInterval(interval time.Duration) MeterProviderOptio
 	}
 }
 
+// WithPrometheusExporter allows to enable the Prometheus exporter
+func WithPrometheusExporter(registerer prometheus.Registerer) MeterProviderOption {
+	return func(c *meterProviderConfig) {
+		c.prometheusRegisterer = registerer
+	}
+}
+
 // WithDefaultHistogramBucketBoundaries lets you overwrite the default buckets for all histograms.
 func WithDefaultHistogramBucketBoundaries(boundaries []float64) MeterProviderOption {
 	return func(c *meterProviderConfig) {
-		c.otlpMetricGRPCOptions = append(c.otlpMetricGRPCOptions,
-			otlpmetricgrpc.WithAggregationSelector(func(ik sdkmetric.InstrumentKind) aggregation.Aggregation {
-				switch ik {
-				case sdkmetric.InstrumentKindCounter, sdkmetric.InstrumentKindUpDownCounter,
-					sdkmetric.InstrumentKindObservableCounter, sdkmetric.InstrumentKindObservableUpDownCounter:
-					return aggregation.Sum{}
-				case sdkmetric.InstrumentKindObservableGauge:
-					return aggregation.LastValue{}
-				case sdkmetric.InstrumentKindHistogram:
-					return aggregation.ExplicitBucketHistogram{
-						Boundaries: boundaries,
-					}
+		c.defaultAggregationSelector = func(ik sdkmetric.InstrumentKind) aggregation.Aggregation {
+			switch ik {
+			case sdkmetric.InstrumentKindCounter, sdkmetric.InstrumentKindUpDownCounter,
+				sdkmetric.InstrumentKindObservableCounter, sdkmetric.InstrumentKindObservableUpDownCounter:
+				return aggregation.Sum{}
+			case sdkmetric.InstrumentKindObservableGauge:
+				return aggregation.LastValue{}
+			case sdkmetric.InstrumentKindHistogram:
+				return aggregation.ExplicitBucketHistogram{
+					Boundaries: boundaries,
 				}
-				panic("unknown instrument kind")
-			}),
-		)
+			}
+			panic("unknown instrument kind")
+		}
 	}
 }
 
@@ -135,3 +146,8 @@ func WithHistogramBucketBoundaries(instrumentName, meterName string, boundaries
 		c.views = append(c.views, newView)
 	}
 }
+
+// WithLogger allows to set the logger
+func WithLogger(l logger) Option {
+	return func(c *config) { c.logger = l }
+}