[feature] Initial metrics

cmd/gotosocial/action/server/server.go

@@ -33,6 +33,7 @@ import (
 	apiutil "github.com/superseriousbusiness/gotosocial/internal/api/util"
 	"github.com/superseriousbusiness/gotosocial/internal/cleaner"
 	"github.com/superseriousbusiness/gotosocial/internal/gtserror"
+	"github.com/superseriousbusiness/gotosocial/internal/metrics"
 	"github.com/superseriousbusiness/gotosocial/internal/middleware"
 	tlprocessor "github.com/superseriousbusiness/gotosocial/internal/processing/timeline"
 	"github.com/superseriousbusiness/gotosocial/internal/timeline"
@@ -81,6 +82,11 @@ var Start action.GTSAction = func(ctx context.Context) error {
 		return fmt.Errorf("error initializing tracing: %w", err)
 	}
 
+	// Initialize Metrics
+	if err := metrics.Initialize(); err != nil {
+		return fmt.Errorf("error initializing metrics: %w", err)
+	}
+
 	// Open connection to the database
 	dbService, err := bundb.NewBunDBService(ctx, &state)
 	if err != nil {
@@ -213,13 +219,18 @@ var Start action.GTSAction = func(ctx context.Context) error {
 	if err != nil {
 		return fmt.Errorf("error creating router: %s", err)
 	}
-
 	middlewares := []gin.HandlerFunc{
 		middleware.AddRequestID(config.GetRequestIDHeader()), // requestID middleware must run before tracing
 	}
+
 	if config.GetTracingEnabled() {
 		middlewares = append(middlewares, tracing.InstrumentGin())
 	}
+
+	if config.GetMetricsEnabled() {
+		middlewares = append(middlewares, metrics.InstrumentGin())
+	}
+
 	middlewares = append(middlewares, []gin.HandlerFunc{
 		// note: hooks adding ctx fields must be ABOVE
 		// the logger, otherwise won't be accessible.

cmd/gotosocial/action/testrig/testrig.go

@@ -38,6 +38,7 @@ import (
 	"github.com/superseriousbusiness/gotosocial/internal/gtserror"
 	"github.com/superseriousbusiness/gotosocial/internal/language"
 	"github.com/superseriousbusiness/gotosocial/internal/log"
+	"github.com/superseriousbusiness/gotosocial/internal/metrics"
 	"github.com/superseriousbusiness/gotosocial/internal/middleware"
 	"github.com/superseriousbusiness/gotosocial/internal/oidc"
 	tlprocessor "github.com/superseriousbusiness/gotosocial/internal/processing/timeline"
@@ -68,6 +69,10 @@ var Start action.GTSAction = func(ctx context.Context) error {
 		return fmt.Errorf("error initializing tracing: %w", err)
 	}
 
+	if err := metrics.Initialize(); err != nil {
+		return fmt.Errorf("error initializing metrics: %w", err)
+	}
+
 	// Initialize caches and database
 	state.DB = testrig.NewTestDB(&state)
 
@@ -142,6 +147,11 @@ var Start action.GTSAction = func(ctx context.Context) error {
 	if config.GetTracingEnabled() {
 		middlewares = append(middlewares, tracing.InstrumentGin())
 	}
+
+	if config.GetMetricsEnabled() {
+		middlewares = append(middlewares, metrics.InstrumentGin())
+	}
+
 	middlewares = append(middlewares, []gin.HandlerFunc{
 		middleware.Logger(config.GetLogClientIP()),
 		middleware.UserAgent(),

docs/advanced/index.md

@@ -14,3 +14,4 @@ We consider these topics advanced because applying them incorrectly does have th
 * [Process sandboxing](security/sandboxing.md)
 * [Firewall configuration](security/firewall.md)
 * [Tracing](tracing.md)
+* [Metrics](metrics.md)

docs/advanced/metrics.md

@@ -0,0 +1,37 @@
+# Metrics
+
+GoToSocial comes with [OpenTelemetry][otel] based metrics built-in with pull-style Prometheus exporter. Currently the following metrics are collected:
+
+* Go performance and runtime metrics
+* Gin (HTTP) metrics
+* Bun (database) metrics
+
+How to configure metrics is explained in the [Observability configuration reference][obs].
+
+For a quickstart, add the following to your GoToSocial configuration and restart your instance:
+
+```yaml
+metrics-enabled: true
+metrics-auth-enabled: true
+metrics-auth-username: some_username
+metrics-auth-password: some_password
+```
+
+This will expose the metrics under the endpoint `/metrics`, protected with HTTP Basic Authentication.
+
+A following is an example how to configure a job for collecting the metrics in Prometheus `scrape_configs`:
+
+```yaml
+  - job_name: gotosocial
+    metrics_path: /metrics
+    scheme: https
+    basic_auth:
+        username: some_username
+        password: some_password
+    static_configs:
+    - targets:
+      - example.org
+```
+
+[otel]: https://opentelemetry.io/
+[obs]: ../configuration/observability.md

docs/configuration/observability.md

@@ -34,4 +34,20 @@ tracing-endpoint: ""
 # Bool. Disable TLS for the gRPC and HTTP transport protocols.
 # Default: false
 tracing-insecure-transport: false
-```
+
+# Bool. Enable OpenTelemetry based metrics support.
+# Default: false
+metrics-enabled: false
+
+# Bool. Enable HTTP Basic Authentication for Prometheus metrics endpoint.
+# Default: false
+metrics-auth-enabled: false
+
+# String. Username for Prometheus metrics endpoint.
+# Default: ""
+metrics-auth-username: ""
+
+# String. Password for Prometheus metrics endpoint.
+# Default: ""
+metrics-auth-password: ""
+```

example/config.yaml

@@ -793,6 +793,22 @@ tracing-endpoint: ""
 # Default: false
 tracing-insecure-transport: false
 
+# Bool. Enable OpenTelemetry based metrics support.
+# Default: false
+metrics-enabled: false
+
+# Bool. Enable HTTP Basic Authentication for Prometheus metrics endpoint.
+# Default: false
+metrics-auth-enabled: false
+
+# String. Username for Prometheus metrics endpoint.
+# Default: ""
+metrics-auth-username: ""
+
+# String. Password for Prometheus metrics endpoint.
+# Default: ""
+metrics-auth-password: ""
+
 ################################
 ##### HTTP CLIENT SETTINGS #####
 ################################

go.mod

@@ -40,13 +40,15 @@ require (
 	github.com/minio/minio-go/v7 v7.0.63
 	github.com/mitchellh/mapstructure v1.5.0
 	github.com/oklog/ulid v1.3.1
+	github.com/prometheus/client_golang v1.17.0
 	github.com/spf13/cobra v1.8.0
 	github.com/spf13/viper v1.16.0
 	github.com/stretchr/testify v1.8.4
 	github.com/superseriousbusiness/activity v1.4.0-gts
 	github.com/superseriousbusiness/exif-terminator v0.5.0
 	github.com/superseriousbusiness/oauth2/v4 v4.3.2-SSB.0.20230227143000-f4900831d6c8
 	github.com/tdewolff/minify/v2 v2.20.7
+	github.com/technologize/otel-go-contrib v1.1.0
 	github.com/tomnomnom/linkheader v0.0.0-20180905144013-02ca5825eb80
 	github.com/ulule/limiter/v3 v3.11.2
 	github.com/uptrace/bun v1.1.16
@@ -56,9 +58,11 @@ require (
 	github.com/wagslane/go-password-validator v0.3.0
 	github.com/yuin/goldmark v1.6.0
 	go.opentelemetry.io/otel v1.21.0
-	go.opentelemetry.io/otel/exporters/otlp/otlptrace/otlptracegrpc v1.20.0
-	go.opentelemetry.io/otel/exporters/otlp/otlptrace/otlptracehttp v1.20.0
-	go.opentelemetry.io/otel/sdk v1.20.0
+	go.opentelemetry.io/otel/exporters/otlp/otlptrace/otlptracegrpc v1.21.0
+	go.opentelemetry.io/otel/exporters/otlp/otlptrace/otlptracehttp v1.21.0
+	go.opentelemetry.io/otel/exporters/prometheus v0.43.0
+	go.opentelemetry.io/otel/sdk v1.21.0
+	go.opentelemetry.io/otel/sdk/metric v1.21.0
 	go.opentelemetry.io/otel/trace v1.21.0
 	go.uber.org/automaxprocs v1.5.3
 	golang.org/x/crypto v0.14.0
@@ -81,8 +85,10 @@ require (
 	codeberg.org/gruf/go-mangler v1.2.3 // indirect
 	codeberg.org/gruf/go-maps v1.0.3 // indirect
 	github.com/aymerick/douceur v0.2.0 // indirect
+	github.com/beorn7/perks v1.0.1 // indirect
 	github.com/bytedance/sonic v1.9.1 // indirect
 	github.com/cenkalti/backoff/v4 v4.2.1 // indirect
+	github.com/cespare/xxhash/v2 v2.2.0 // indirect
 	github.com/chenzhuoyu/base64x v0.0.0-20221115062448-fe3a3abad311 // indirect
 	github.com/cilium/ebpf v0.9.1 // indirect
 	github.com/containerd/cgroups/v3 v3.0.1 // indirect
@@ -131,6 +137,7 @@ require (
 	github.com/leodido/go-urn v1.2.4 // indirect
 	github.com/magiconair/properties v1.8.7 // indirect
 	github.com/mattn/go-isatty v0.0.19 // indirect
+	github.com/matttproud/golang_protobuf_extensions v1.0.4 // indirect
 	github.com/minio/md5-simd v1.1.2 // indirect
 	github.com/minio/sha256-simd v1.0.1 // indirect
 	github.com/modern-go/concurrent v0.0.0-20180306012644-bacd9c7ef1dd // indirect
@@ -139,6 +146,9 @@ require (
 	github.com/pelletier/go-toml/v2 v2.0.8 // indirect
 	github.com/pkg/errors v0.9.1 // indirect
 	github.com/pmezard/go-difflib v1.0.0 // indirect
+	github.com/prometheus/client_model v0.5.0 // indirect
+	github.com/prometheus/common v0.44.0 // indirect
+	github.com/prometheus/procfs v0.11.1 // indirect
 	github.com/quasoft/memstore v0.0.0-20191010062613-2bce066d2b0b // indirect
 	github.com/remyoudompheng/bigfft v0.0.0-20230129092748-24d4a6f8daec // indirect
 	github.com/rs/xid v1.5.0 // indirect
@@ -156,7 +166,7 @@ require (
 	github.com/uptrace/opentelemetry-go-extra/otelsql v0.2.2 // indirect
 	github.com/vmihailenco/msgpack/v5 v5.3.5 // indirect
 	github.com/vmihailenco/tagparser/v2 v2.0.0 // indirect
-	go.opentelemetry.io/otel/exporters/otlp/otlptrace v1.20.0 // indirect
+	go.opentelemetry.io/otel/exporters/otlp/otlptrace v1.21.0 // indirect
 	go.opentelemetry.io/otel/metric v1.21.0 // indirect
 	go.opentelemetry.io/proto/otlp v1.0.0 // indirect
 	golang.org/x/arch v0.3.0 // indirect

go.sum

@@ -91,6 +91,8 @@ github.com/andybalholm/brotli v1.0.5 h1:8uQZIdzKmjc/iuPu7O2ioW48L81FgatrcpfFmiq/
 github.com/andybalholm/brotli v1.0.5/go.mod h1:fO7iG3H7G2nSZ7m0zPUDn85XEX2GTukHGRSepvi9Eig=
 github.com/aymerick/douceur v0.2.0 h1:Mv+mAeH1Q+n9Fr+oyamOlAkUNPWPlA8PPGR0QAaYuPk=
 github.com/aymerick/douceur v0.2.0/go.mod h1:wlT5vV2O3h55X9m7iVYN0TBM0NH/MmbLnd30/FjWUq4=
+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/buckket/go-blurhash v1.1.0 h1:X5M6r0LIvwdvKiUtiNcRL2YlmOfMzYobI3VCKCZc9Do=
 github.com/buckket/go-blurhash v1.1.0/go.mod h1:aT2iqo5W9vu9GpyoLErKfTHwgODsZp3bQfXjXJUxNb8=
 github.com/bytedance/sonic v1.5.0/go.mod h1:ED5hyg4y6t3/9Ku1R6dU/4KyJ48DZ4jPhfY1O2AihPM=
@@ -99,6 +101,8 @@ github.com/bytedance/sonic v1.9.1/go.mod h1:i736AoUSYt75HyZLoJW9ERYxcy6eaN6h4BZX
 github.com/cenkalti/backoff/v4 v4.2.1 h1:y4OZtCnogmCPw98Zjyt5a6+QwPLGkiQsYW5oUqylYbM=
 github.com/cenkalti/backoff/v4 v4.2.1/go.mod h1:Y3VNntkOUPxTVeUxJ/G5vcM//AlwfmyYozVcomhLiZE=
 github.com/census-instrumentation/opencensus-proto v0.2.1/go.mod h1:f6KPmirojxKA12rnyqOA5BBL4O983OfeGPqjHWSTneU=
+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/chenzhuoyu/base64x v0.0.0-20211019084208-fb5309c8db06/go.mod h1:DH46F32mSOjUmXrMHnKwZdA8wcEefY7UVqBKYGjpdQY=
 github.com/chenzhuoyu/base64x v0.0.0-20221115062448-fe3a3abad311 h1:qSGYFH7+jGhDF8vLC+iwCD4WpbV1EBDSzWkJODFLams=
 github.com/chenzhuoyu/base64x v0.0.0-20221115062448-fe3a3abad311/go.mod h1:b583jCggY9gE99b6G5LEC39OIiVsWj+R97kbl5odCEk=
@@ -388,6 +392,8 @@ github.com/mattn/go-isatty v0.0.19 h1:JITubQf0MOLdlGRuRq+jtsDlekdYPia9ZFsB8h/APP
 github.com/mattn/go-isatty v0.0.19/go.mod h1:W+V8PltTTMOvKvAeJH7IuucS94S2C6jfK/D7dTCTo3Y=
 github.com/mattn/go-sqlite3 v2.0.3+incompatible h1:gXHsfypPkaMZrKbD5209QV9jbUTJKjyR5WD3HYQSd+U=
 github.com/mattn/go-sqlite3 v2.0.3+incompatible/go.mod h1:FPy6KqzDD04eiIsT53CuJW3U88zkxoIYsOqkbpncsNc=
+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/microcosm-cc/bluemonday v1.0.26 h1:xbqSvqzQMeEHCqMi64VAs4d8uy6Mequs3rQ0k/Khz58=
 github.com/microcosm-cc/bluemonday v1.0.26/go.mod h1:JyzOCs9gkyQyjs+6h10UEVSe02CGwkhd72Xdqh78TWs=
 github.com/miekg/dns v1.1.56 h1:5imZaSeoRNvpM9SzWNhEcP9QliKiz20/dA2QabIGVnE=
@@ -432,7 +438,15 @@ github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZb
 github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
 github.com/prashantv/gostub v1.1.0 h1:BTyx3RfQjRHnUWaGF9oQos79AlQ5k8WNktv7VGvVH4g=
 github.com/prashantv/gostub v1.1.0/go.mod h1:A5zLQHz7ieHGG7is6LLXLz7I8+3LZzsrV0P1IAHhP5U=
+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 v0.0.0-20190812154241-14fe0d1b01d4/go.mod h1:xMI15A0UPsDsEKsMN9yxemIoYk6Tm2C1GtYGdfGttqA=
+github.com/prometheus/client_model v0.5.0 h1:VQw1hfvPvk3Uv6Qf29VrPF32JB6rtbgI6cYPYQjL0Qw=
+github.com/prometheus/client_model v0.5.0/go.mod h1:dTiFglRmd66nLR9Pv9f0mZi7B7fk5Pm3gvsjB5tr+kI=
+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 v0.11.1 h1:xRC8Iq1yyca5ypa9n1EZnWZkt7dwcoRPQwX/5gwaUuI=
+github.com/prometheus/procfs v0.11.1/go.mod h1:eesXgaPo1q7lBpVMoMy0ZOFTth9hBn4W/y0/p/ScXhY=
 github.com/quasoft/memstore v0.0.0-20191010062613-2bce066d2b0b h1:aUNXCGgukb4gtY99imuIeoh8Vr0GSwAlYxPAhqZrpFc=
 github.com/quasoft/memstore v0.0.0-20191010062613-2bce066d2b0b/go.mod h1:wTPjTepVu7uJBYgZ0SdWHQlIas582j6cn2jgk4DDdlg=
 github.com/remyoudompheng/bigfft v0.0.0-20230129092748-24d4a6f8daec h1:W09IVJc94icq4NjY3clb7Lk8O1qJ8BdBEF8z0ibU0rE=
@@ -499,6 +513,8 @@ github.com/tdewolff/parse/v2 v2.7.5 h1:RdcN3Ja6zAMSvnxxO047xRoWexX3RrXKi3H6EQHzX
 github.com/tdewolff/parse/v2 v2.7.5/go.mod h1:3FbJWZp3XT9OWVN3Hmfp0p/a08v4h8J9W1aghka0soA=
 github.com/tdewolff/test v1.0.11-0.20231101010635-f1265d231d52 h1:gAQliwn+zJrkjAHVcBEYW/RFvd2St4yYimisvozAYlA=
 github.com/tdewolff/test v1.0.11-0.20231101010635-f1265d231d52/go.mod h1:6DAvZliBAAnD7rhVgwaM7DE5/d9NMOAJ09SqYqeK4QE=
+github.com/technologize/otel-go-contrib v1.1.0 h1:gl9bxxJAgXFnKJzoprJOfbvNRE1k3Ky9O7ppVJDb9gg=
+github.com/technologize/otel-go-contrib v1.1.0/go.mod h1:dCN/wj2WyUO8aFZFdIN+6tfJHImjTML/8r2YVYAy3So=
 github.com/tidwall/btree v0.0.0-20191029221954-400434d76274 h1:G6Z6HvJuPjG6XfNGi/feOATzeJrfgTNJY+rGrHbA04E=
 github.com/tidwall/btree v0.0.0-20191029221954-400434d76274/go.mod h1:huei1BkDWJ3/sLXmO+bsCNELL+Bp2Kks9OLyQFkzvA8=
 github.com/tidwall/buntdb v1.1.2 h1:noCrqQXL9EKMtcdwJcmuVKSEjqu1ua99RHHgbLTEHRo=
@@ -581,16 +597,20 @@ go.opencensus.io v0.22.4/go.mod h1:yxeiOL68Rb0Xd1ddK5vPZ/oVn4vY4Ynel7k9FzqtOIw=
 go.opencensus.io v0.22.5/go.mod h1:5pWMHQbX5EPX2/62yrJeAkowc+lfs/XD7Uxpq3pI6kk=
 go.opentelemetry.io/otel v1.21.0 h1:hzLeKBZEL7Okw2mGzZ0cc4k/A7Fta0uoPgaJCr8fsFc=
 go.opentelemetry.io/otel v1.21.0/go.mod h1:QZzNPQPm1zLX4gZK4cMi+71eaorMSGT3A4znnUvNNEo=
-go.opentelemetry.io/otel/exporters/otlp/otlptrace v1.20.0 h1:DeFD0VgTZ+Cj6hxravYYZE2W4GlneVH81iAOPjZkzk8=
-go.opentelemetry.io/otel/exporters/otlp/otlptrace v1.20.0/go.mod h1:GijYcYmNpX1KazD5JmWGsi4P7dDTTTnfv1UbGn84MnU=
-go.opentelemetry.io/otel/exporters/otlp/otlptrace/otlptracegrpc v1.20.0 h1:gvmNvqrPYovvyRmCSygkUDyL8lC5Tl845MLEwqpxhEU=
-go.opentelemetry.io/otel/exporters/otlp/otlptrace/otlptracegrpc v1.20.0/go.mod h1:vNUq47TGFioo+ffTSnKNdob241vePmtNZnAODKapKd0=
-go.opentelemetry.io/otel/exporters/otlp/otlptrace/otlptracehttp v1.20.0 h1:CsBiKCiQPdSjS+MlRiqeTI9JDDpSuk0Hb6QTRfwer8k=
-go.opentelemetry.io/otel/exporters/otlp/otlptrace/otlptracehttp v1.20.0/go.mod h1:CMJYNAfooOwSZSAmAeMUV1M+TXld3BiK++z9fqIm2xk=
+go.opentelemetry.io/otel/exporters/otlp/otlptrace v1.21.0 h1:cl5P5/GIfFh4t6xyruOgJP5QiA1pw4fYYdv6nc6CBWw=
+go.opentelemetry.io/otel/exporters/otlp/otlptrace v1.21.0/go.mod h1:zgBdWWAu7oEEMC06MMKc5NLbA/1YDXV1sMpSqEeLQLg=
+go.opentelemetry.io/otel/exporters/otlp/otlptrace/otlptracegrpc v1.21.0 h1:tIqheXEFWAZ7O8A7m+J0aPTmpJN3YQ7qetUAdkkkKpk=
+go.opentelemetry.io/otel/exporters/otlp/otlptrace/otlptracegrpc v1.21.0/go.mod h1:nUeKExfxAQVbiVFn32YXpXZZHZ61Cc3s3Rn1pDBGAb0=
+go.opentelemetry.io/otel/exporters/otlp/otlptrace/otlptracehttp v1.21.0 h1:digkEZCJWobwBqMwC0cwCq8/wkkRy/OowZg5OArWZrM=
+go.opentelemetry.io/otel/exporters/otlp/otlptrace/otlptracehttp v1.21.0/go.mod h1:/OpE/y70qVkndM0TrxT4KBoN3RsFZP0QaofcfYrj76I=
+go.opentelemetry.io/otel/exporters/prometheus v0.43.0 h1:Skkl6akzvdWweXX6LLAY29tyFSO6hWZ26uDbVGTDXe8=
+go.opentelemetry.io/otel/exporters/prometheus v0.43.0/go.mod h1:nZStMoc1H/YJpRjSx9IEX4abBMekORTLQcTUT1CgLkg=
 go.opentelemetry.io/otel/metric v1.21.0 h1:tlYWfeo+Bocx5kLEloTjbcDwBuELRrIFxwdQ36PlJu4=
 go.opentelemetry.io/otel/metric v1.21.0/go.mod h1:o1p3CA8nNHW8j5yuQLdc1eeqEaPfzug24uvsyIEJRWM=
-go.opentelemetry.io/otel/sdk v1.20.0 h1:5Jf6imeFZlZtKv9Qbo6qt2ZkmWtdWx/wzcCbNUlAWGM=
-go.opentelemetry.io/otel/sdk v1.20.0/go.mod h1:rmkSx1cZCm/tn16iWDn1GQbLtsW/LvsdEEFzCSRM6V0=
+go.opentelemetry.io/otel/sdk v1.21.0 h1:FTt8qirL1EysG6sTQRZ5TokkU8d0ugCj8htOgThZXQ8=
+go.opentelemetry.io/otel/sdk v1.21.0/go.mod h1:Nna6Yv7PWTdgJHVRD9hIYywQBRx7pbox6nwBnZIxl/E=
+go.opentelemetry.io/otel/sdk/metric v1.21.0 h1:smhI5oD714d6jHE6Tie36fPx4WDFIg+Y6RfAY4ICcR0=
+go.opentelemetry.io/otel/sdk/metric v1.21.0/go.mod h1:FJ8RAsoPGv/wYMgBdUJXOm+6pzFY3YdljnXtv1SBE8Q=
 go.opentelemetry.io/otel/trace v1.21.0 h1:WD9i5gzvoUPuXIXH24ZNBudiarZDKuekPqi/E8fpfLc=
 go.opentelemetry.io/otel/trace v1.21.0/go.mod h1:LGbsEB0f9LGjN+OZaQQ26sohbOmiMR+BaslueVtS/qQ=
 go.opentelemetry.io/proto/otlp v1.0.0 h1:T0TX0tmXU8a3CbNXzEKGeU5mIVOdf0oykP+u2lIVU/I=

internal/config/config.go

@@ -140,6 +140,11 @@ type Configuration struct {
 	TracingEndpoint          string `name:"tracing-endpoint" usage:"Endpoint of your trace collector. Eg., 'localhost:4317' for gRPC, 'localhost:4318' for http"`
 	TracingInsecureTransport bool   `name:"tracing-insecure-transport" usage:"Disable TLS for the gRPC or HTTP transport protocol"`
 
+	MetricsEnabled      bool   `name:"metrics-enabled" usage:"Enable OpenTelemetry based metrics support."`
+	MetricsAuthEnabled  bool   `name:"metrics-auth-enabled" usage:"Enable HTTP Basic Authentication for Prometheus metrics endpoint"`
+	MetricsAuthUsername string `name:"metrics-auth-username" usage:"Username for Prometheus metrics endpoint"`
+	MetricsAuthPassword string `name:"metrics-auth-password" usage:"Password for Prometheus metrics endpoint"`
+
 	SMTPHost               string `name:"smtp-host" usage:"Host of the smtp server. Eg., 'smtp.eu.mailgun.org'"`
 	SMTPPort               int    `name:"smtp-port" usage:"Port of the smtp server. Eg., 587"`
 	SMTPUsername           string `name:"smtp-username" usage:"Username to authenticate with the smtp server as. Eg., 'postmaster@mail.example.org'"`

internal/config/defaults.go

@@ -121,6 +121,9 @@ var Defaults = Configuration{
 	TracingEndpoint:          "",
 	TracingInsecureTransport: false,
 
+	MetricsEnabled:     false,
+	MetricsAuthEnabled: false,
+
 	SyslogEnabled:  false,
 	SyslogProtocol: "udp",
 	SyslogAddress:  "localhost:514",