chore(telemetry): move configuration to node config (gnolang#2021)

This PR moves Telemetry configuration to the centralised node config.
h/t to @albttx for identifying this.

gno.land/cmd/gnoland/start.go

@@ -5,7 +5,6 @@ import (
 	"errors"
 	"flag"
 	"fmt"
-	"os"
 	"path/filepath"
 	"strings"
 	"time"
@@ -219,12 +218,6 @@ func execStart(c *startCfg, io commands.IO) error {
 		loadCfgErr error
 	)
 
-	// Attempt to initialize telemetry. If the environment variables required to initialize
-	// telemetry are not set, then the initialization will do nothing.
-	if err := initTelemetry(); err != nil {
-		return fmt.Errorf("error initializing telemetry: %w", err)
-	}
-
 	// Set the node configuration
 	if c.nodeConfigPath != "" {
 		// Load the node configuration
@@ -254,6 +247,9 @@ func execStart(c *startCfg, io commands.IO) error {
 	// Wrap the zap logger
 	logger := log.ZapLoggerToSlog(zapLogger)
 
+	// Initialize telemetry
+	telemetry.Init(*cfg.Telemetry)
+
 	// Write genesis file if missing.
 	// NOTE: this will be dropped in a PR that resolves issue #1886:
 	// https://github.com/gnolang/gno/issues/1886
@@ -399,19 +395,3 @@ func getTxEventStoreConfig(c *startCfg) (*eventstorecfg.Config, error) {
 
 	return cfg, nil
 }
-
-func initTelemetry() error {
-	var options []telemetry.Option
-
-	if os.Getenv("TELEM_METRICS_ENABLED") == "true" {
-		options = append(options, telemetry.WithOptionMetricsEnabled())
-	}
-
-	// The string options can be added by default. Their absence would yield the same result
-	// as if the option were excluded altogether.
-	options = append(options, telemetry.WithOptionMeterName(os.Getenv("TELEM_METER_NAME")))
-	options = append(options, telemetry.WithOptionExporterEndpoint(os.Getenv("TELEM_EXPORTER_ENDPOINT")))
-	options = append(options, telemetry.WithOptionServiceName(os.Getenv("TELEM_SERVICE_NAME")))
-
-	return telemetry.Init(options...)
-}

tm2/pkg/bft/config/config.go

@@ -16,6 +16,7 @@ import (
 	"github.com/gnolang/gno/tm2/pkg/errors"
 	osm "github.com/gnolang/gno/tm2/pkg/os"
 	p2p "github.com/gnolang/gno/tm2/pkg/p2p/config"
+	telemetry "github.com/gnolang/gno/tm2/pkg/telemetry/config"
 )
 
 var (
@@ -51,6 +52,7 @@ type Config struct {
 	Mempool      *mem.MempoolConfig   `toml:"mempool" comment:"##### mempool configuration options #####"`
 	Consensus    *cns.ConsensusConfig `toml:"consensus" comment:"##### consensus configuration options #####"`
 	TxEventStore *eventstore.Config   `toml:"tx_event_store" comment:"##### event store #####"`
+	Telemetry    *telemetry.Config    `toml:"telemetry" comment:"##### node telemetry #####"`
 }
 
 // DefaultConfig returns a default configuration for a Tendermint node
@@ -62,6 +64,7 @@ func DefaultConfig() *Config {
 		Mempool:      mem.DefaultMempoolConfig(),
 		Consensus:    cns.DefaultConsensusConfig(),
 		TxEventStore: eventstore.DefaultEventStoreConfig(),
+		Telemetry:    telemetry.DefaultTelemetryConfig(),
 	}
 }
 
@@ -138,6 +141,7 @@ func TestConfig() *Config {
 		Mempool:      mem.TestMempoolConfig(),
 		Consensus:    cns.TestConsensusConfig(),
 		TxEventStore: eventstore.DefaultEventStoreConfig(),
+		Telemetry:    telemetry.TestTelemetryConfig(),
 	}
 }
 

tm2/pkg/telemetry/README.md

@@ -1,13 +1,11 @@
 # Telemetry
 
-The purpose of this package is to provide a way to easily integrate OpenTelemetry Protocol (OTLP) metrics collection into our codebase.
+The purpose of this package is to provide a way to easily integrate OpenTelemetry Protocol (OTLP) metrics collection into a Tendermint 2 node.
 
-## Configure environment variables
-Metrics can be enabled using environment variables. The following variables are supported:
-- `TELEM_METRICS_ENABLED`: setting to `true` will enable metrics collection
-- `TELEM_METER_NAME`: optionally set the meter name; the default is `gno.land`
-- `TELEM_SERVICE_NAME`: optionally set the service name; the default is `gno.land`
-- `TELEM_EXPORTER_ENDPOINT`: required; this is the endpoint to export metrics to, like a local OTEL collector
+## Configure Telemetry
+
+Telemetry can be regularly configured within the TM2 node through the
+`[telemetry]` section. It is disabled by default.
 
 ## OTEL configuration
 There are many ways configure the OTEL pipeline for exporting metrics. Here is an example of how a local OTEL collector can be configured to send metrics to Grafana Cloud. This is an optional step and can be highly customized.
@@ -40,4 +38,4 @@ Collector exporter environment variables, including those for authentication, ca
 
 ## Resources
 - https://opentelemetry.io/docs/collector/
-- https://grafana.com/docs/grafana-cloud/monitor-applications/application-observability/setup/collector/
+- https://grafana.com/docs/grafana-cloud/monitor-applications/application-observability/setup/collector/

tm2/pkg/telemetry/config/config.go

@@ -0,0 +1,27 @@
+// Package config contains the configuration types and helpers for the telemetry
+// package.
+package config
+
+// Config is the configuration struct for the tm2 telemetry package.
+type Config struct {
+	MetricsEnabled   bool   `toml:"enabled"`
+	MeterName        string `toml:"meter_name"`
+	ServiceName      string `toml:"service_name"`
+	ExporterEndpoint string `toml:"exporter_endpoint" comment:"the endpoint to export metrics to, like a local OpenTelemetry collector"`
+}
+
+// DefaultTelemetryConfig is the default configuration used for the node.
+func DefaultTelemetryConfig() *Config {
+	return &Config{
+		MetricsEnabled:   false,
+		MeterName:        "gno.land",
+		ServiceName:      "gno.land",
+		ExporterEndpoint: "",
+	}
+}
+
+// TestTelemetryConfig is the test configuration. Currently it is an alias for
+// [DefaultTelemetryConfig].
+func TestTelemetryConfig() *Config {
+	return DefaultTelemetryConfig()
+}

tm2/pkg/telemetry/init.go

@@ -4,37 +4,33 @@ package telemetry
 // https://github.com/open-telemetry/opentelemetry-go/blob/main/example/prometheus/main.go
 
 import (
+	"sync/atomic"
+
+	"github.com/gnolang/gno/tm2/pkg/telemetry/config"
 	"github.com/gnolang/gno/tm2/pkg/telemetry/metrics"
-	"github.com/gnolang/gno/tm2/pkg/telemetry/options"
 )
 
-const (
-	defaultMeterName   = "gno.land"
-	defaultServiceName = "gno.land"
+var (
+	globalConfig    config.Config
+	globalConfigSet atomic.Bool
 )
 
-var config options.Config
-
 // MetricsEnabled returns true if metrics have been initialized.
 func MetricsEnabled() bool {
-	return config.MetricsEnabled
+	return globalConfig.MetricsEnabled
 }
 
-// Init will initialize metrics with the options provided. This function may also initialize tracing when
-// this is something that we want to support.
-func Init(options ...Option) error {
-	config.MeterName = defaultMeterName
-	config.ServiceName = defaultServiceName
-	for _, opt := range options {
-		opt(&config)
+// Init sets the configuration for telemetry to c, and if telemetry is enabled,
+// starts tracking.
+// Init may only be called once. Multiple calls to Init will panic.
+func Init(c config.Config) error {
+	if !globalConfigSet.CompareAndSwap(false, true) {
+		panic("telemetry configuration has already been set and initialised")
 	}
-
+	globalConfig = c
 	// Initialize metrics to be collected.
-	if config.MetricsEnabled {
-		if err := metrics.Init(config); err != nil {
-			return err
-		}
+	if c.MetricsEnabled {
+		return metrics.Init(c)
 	}
-
 	return nil
 }

tm2/pkg/telemetry/metrics/init.go

@@ -3,8 +3,8 @@ package metrics
 import (
 	"context"
 
+	"github.com/gnolang/gno/tm2/pkg/telemetry/config"
 	"github.com/gnolang/gno/tm2/pkg/telemetry/exporter"
-	"github.com/gnolang/gno/tm2/pkg/telemetry/options"
 	"go.opentelemetry.io/otel"
 	"go.opentelemetry.io/otel/exporters/otlp/otlpmetric/otlpmetricgrpc"
 	"go.opentelemetry.io/otel/metric"
@@ -19,7 +19,7 @@ var (
 	BuildBlockTimer  metric.Int64Histogram
 )
 
-func Init(config options.Config) error {
+func Init(config config.Config) error {
 	if config.ExporterEndpoint == "" {
 		return exporter.ErrEndpointNotSet
 	}