feat: add opentelemetry tracing

cmd/cosmos-wallets-exporter.go

@@ -13,7 +13,7 @@ var (
 )
 
 func ExecuteMain(configPath string) {
-	app := pkg.NewApp(configPath)
+	app := pkg.NewApp(configPath, version)
 	app.Start()
 }
 

go.mod

@@ -1,27 +1,47 @@
 module main
 
-go 1.18
+go 1.21.4
+
+toolchain go1.22.1
 
 require (
 	github.com/BurntSushi/toml v1.1.0
-	github.com/google/uuid v1.3.0
+	github.com/google/uuid v1.6.0
+	github.com/guregu/null/v5 v5.0.0
 	github.com/mcuadros/go-defaults v1.2.0
 	github.com/prometheus/client_golang v1.12.2
 	github.com/rs/zerolog v1.26.1
 	github.com/spf13/cobra v1.4.0
-	github.com/superoo7/go-gecko v1.0.0
+	go.opentelemetry.io/contrib/instrumentation/net/http/otelhttp v0.51.0
+	go.opentelemetry.io/otel v1.26.0
+	go.opentelemetry.io/otel/exporters/otlp/otlptrace/otlptracehttp v1.26.0
+	go.opentelemetry.io/otel/sdk v1.26.0
+	go.opentelemetry.io/otel/trace v1.26.0
 )
 
 require (
 	github.com/beorn7/perks v1.0.1 // indirect
-	github.com/cespare/xxhash/v2 v2.1.2 // indirect
-	github.com/golang/protobuf v1.5.2 // indirect
+	github.com/cenkalti/backoff/v4 v4.3.0 // indirect
+	github.com/cespare/xxhash/v2 v2.2.0 // indirect
+	github.com/felixge/httpsnoop v1.0.4 // indirect
+	github.com/go-logr/logr v1.4.1 // indirect
+	github.com/go-logr/stdr v1.2.2 // indirect
+	github.com/golang/protobuf v1.5.4 // indirect
+	github.com/grpc-ecosystem/grpc-gateway/v2 v2.19.1 // indirect
 	github.com/inconshreveable/mousetrap v1.0.0 // indirect
 	github.com/matttproud/golang_protobuf_extensions v1.0.1 // indirect
 	github.com/prometheus/client_model v0.2.0 // indirect
 	github.com/prometheus/common v0.32.1 // indirect
 	github.com/prometheus/procfs v0.7.3 // indirect
 	github.com/spf13/pflag v1.0.5 // indirect
-	golang.org/x/sys v0.0.0-20220114195835-da31bd327af9 // indirect
-	google.golang.org/protobuf v1.26.0 // indirect
+	go.opentelemetry.io/otel/exporters/otlp/otlptrace v1.26.0 // indirect
+	go.opentelemetry.io/otel/metric v1.26.0 // indirect
+	go.opentelemetry.io/proto/otlp v1.2.0 // indirect
+	golang.org/x/net v0.23.0 // indirect
+	golang.org/x/sys v0.19.0 // indirect
+	golang.org/x/text v0.14.0 // indirect
+	google.golang.org/genproto/googleapis/api v0.0.0-20240227224415-6ceb2ff114de // indirect
+	google.golang.org/genproto/googleapis/rpc v0.0.0-20240401170217-c3f982113cda // indirect
+	google.golang.org/grpc v1.63.2 // indirect
+	google.golang.org/protobuf v1.33.0 // indirect
 )

pkg/app.go

@@ -1,28 +1,36 @@
 package pkg
 
 import (
+	"context"
 	coingeckoPkg "main/pkg/coingecko"
 	"main/pkg/config"
 	"main/pkg/logger"
 	queriersPkg "main/pkg/queriers"
+	"main/pkg/tracing"
 	"main/pkg/types"
 	"net/http"
 	"sync"
 	"time"
 
+	"go.opentelemetry.io/contrib/instrumentation/net/http/otelhttp"
+	"go.opentelemetry.io/otel/attribute"
+
 	"github.com/google/uuid"
 	"github.com/prometheus/client_golang/prometheus"
 	"github.com/prometheus/client_golang/prometheus/promhttp"
 	"github.com/rs/zerolog"
+	"go.opentelemetry.io/otel/trace"
 )
 
 type App struct {
 	Config   *config.Config
 	Logger   zerolog.Logger
 	Queriers []types.Querier
+
+	Tracer trace.Tracer
 }
 
-func NewApp(configPath string) *App {
+func NewApp(configPath string, version string) *App {
 	appConfig, err := config.GetConfig(configPath)
 	if err != nil {
 		logger.GetDefaultLogger().Fatal().Err(err).Msg("Could not load config")
@@ -32,26 +40,31 @@ func NewApp(configPath string) *App {
 		logger.GetDefaultLogger().Fatal().Err(err).Msg("Provided config is invalid!")
 	}
 
+	tracer, err := tracing.InitTracer(appConfig.TracingConfig, version)
+	if err != nil {
+		logger.GetDefaultLogger().Fatal().Err(err).Msg("Error setting up tracing")
+	}
+
 	log := logger.GetLogger(appConfig.LogConfig)
-	coingecko := coingeckoPkg.NewCoingecko(appConfig, log)
+	coingecko := coingeckoPkg.NewCoingecko(appConfig, log, tracer)
 
 	queriers := []types.Querier{
-		queriersPkg.NewPriceQuerier(appConfig, coingecko),
-		queriersPkg.NewBalanceQuerier(appConfig, log),
-		queriersPkg.NewUptimeQuerier(),
+		queriersPkg.NewPriceQuerier(appConfig, coingecko, tracer),
+		queriersPkg.NewBalanceQuerier(appConfig, log, tracer),
+		queriersPkg.NewUptimeQuerier(tracer),
 	}
 
 	return &App{
 		Config:   appConfig,
 		Logger:   log,
 		Queriers: queriers,
+		Tracer:   tracer,
 	}
 }
 
 func (a *App) Start() {
-	http.HandleFunc("/metrics", func(w http.ResponseWriter, r *http.Request) {
-		a.Handler(w, r)
-	})
+	otelHandler := otelhttp.NewHandler(http.HandlerFunc(a.Handler), "prometheus")
+	http.Handle("/metrics", otelHandler)
 
 	a.Logger.Info().Str("addr", a.Config.ListenAddress).Msg("Listening")
 	err := http.ListenAndServe(a.Config.ListenAddress, nil)
@@ -62,11 +75,18 @@ func (a *App) Start() {
 
 func (a *App) Handler(w http.ResponseWriter, r *http.Request) {
 	requestStart := time.Now()
+	requestID := uuid.New().String()
 
 	sublogger := a.Logger.With().
-		Str("request-id", uuid.New().String()).
+		Str("request-id", requestID).
 		Logger()
 
+	span := trace.SpanFromContext(r.Context())
+	span.SetAttributes(attribute.String("request-id", requestID))
+	rootSpanCtx := r.Context()
+
+	defer span.End()
+
 	registry := prometheus.NewRegistry()
 
 	var wg sync.WaitGroup
@@ -76,16 +96,15 @@ func (a *App) Handler(w http.ResponseWriter, r *http.Request) {
 
 	for _, querier := range a.Queriers {
 		wg.Add(1)
-		go func(querier types.Querier) {
-			mutex.Lock()
+		go func(querier types.Querier, ctx context.Context) {
+			metrics, querierQueryInfos := querier.GetMetrics(ctx)
 
-			metrics, querierQueryInfos := querier.GetMetrics()
+			mutex.Lock()
 			registry.MustRegister(metrics...)
 			queryInfos = append(queryInfos, querierQueryInfos...)
-
 			mutex.Unlock()
 			wg.Done()
-		}(querier)
+		}(querier, rootSpanCtx)
 	}
 
 	wg.Wait()

pkg/coingecko/coingecko.go

@@ -1,12 +1,15 @@
 package coingecko
 
 import (
+	"context"
 	"fmt"
 	"main/pkg/config"
 	"main/pkg/http"
 	"main/pkg/types"
 	"strings"
 
+	"go.opentelemetry.io/otel/trace"
+
 	"github.com/rs/zerolog"
 )
 
@@ -16,22 +19,27 @@ type Coingecko struct {
 	Client *http.Client
 	Config *config.Config
 	Logger zerolog.Logger
+	Tracer trace.Tracer
 }
 
-func NewCoingecko(appConfig *config.Config, logger zerolog.Logger) *Coingecko {
+func NewCoingecko(appConfig *config.Config, logger zerolog.Logger, tracer trace.Tracer) *Coingecko {
 	return &Coingecko{
 		Config: appConfig,
-		Client: http.NewClient(logger, "coingecko"),
+		Client: http.NewClient(logger, "coingecko", tracer),
 		Logger: logger.With().Str("component", "coingecko").Logger(),
+		Tracer: tracer,
 	}
 }
 
-func (c *Coingecko) FetchPrices(currencies []string) (map[string]float64, types.QueryInfo) {
+func (c *Coingecko) FetchPrices(currencies []string, ctx context.Context) (map[string]float64, types.QueryInfo) {
+	childCtx, span := c.Tracer.Start(ctx, "Querying prices")
+	defer span.End()
+
 	ids := strings.Join(currencies, ",")
 	url := fmt.Sprintf("https://api.coingecko.com/api/v3/simple/price?ids=%s&vs_currencies=usd", ids)
 
 	var response Response
-	queryInfo, _, err := c.Client.Get(url, &response, types.HTTPPredicateAlwaysPass())
+	queryInfo, _, err := c.Client.Get(url, &response, types.HTTPPredicateAlwaysPass(), childCtx)
 	if err != nil {
 		c.Logger.Error().Err(err).Msg("Could not get rate")
 		return nil, queryInfo

pkg/config/config.go

@@ -5,6 +5,8 @@ import (
 	"fmt"
 	"os"
 
+	"github.com/guregu/null/v5"
+
 	"github.com/BurntSushi/toml"
 	"github.com/mcuadros/go-defaults"
 )
@@ -78,16 +80,25 @@ func (c *Chain) FindDenomByName(denom string) (*DenomInfo, bool) {
 }
 
 type Config struct {
-	LogConfig     LogConfig `toml:"log"`
-	ListenAddress string    `default:":9550" toml:"listen-address"`
-	Chains        []Chain   `toml:"chains"`
+	TracingConfig TracingConfig `toml:"tracing"`
+	LogConfig     LogConfig     `toml:"log"`
+	ListenAddress string        `default:":9550" toml:"listen-address"`
+	Chains        []Chain       `toml:"chains"`
 }
 
 type LogConfig struct {
 	LogLevel   string `default:"info"  toml:"level"`
 	JSONOutput bool   `default:"false" toml:"json"`
 }
 
+type TracingConfig struct {
+	Enabled                   null.Bool `default:"false"                     toml:"enabled"`
+	OpenTelemetryHTTPHost     string    `toml:"open-telemetry-http-host"`
+	OpenTelemetryHTTPInsecure null.Bool `default:"true"                      toml:"open-telemetry-http-insecure"`
+	OpenTelemetryHTTPUser     string    `toml:"open-telemetry-http-user"`
+	OpenTelemetryHTTPPassword string    `toml:"open-telemetry-http-password"`
+}
+
 func (c *Config) Validate() error {
 	if len(c.Chains) == 0 {
 		return errors.New("no chains provided")

pkg/http/http.go

@@ -1,32 +1,45 @@
 package http
 
 import (
+	"context"
 	"encoding/json"
 	"main/pkg/types"
 	"net/http"
 	"time"
 
+	"go.opentelemetry.io/otel/trace"
+
 	"github.com/rs/zerolog"
+	"go.opentelemetry.io/contrib/instrumentation/net/http/otelhttp"
 )
 
 type Client struct {
 	logger zerolog.Logger
 	chain  string
+	tracer trace.Tracer
 }
 
-func NewClient(logger zerolog.Logger, chain string) *Client {
+func NewClient(logger zerolog.Logger, chain string, tracer trace.Tracer) *Client {
 	return &Client{
 		logger: logger.With().Str("component", "http").Logger(),
 		chain:  chain,
+		tracer: tracer,
 	}
 }
 
 func (c *Client) Get(
 	url string,
 	target interface{},
 	predicate types.HTTPPredicate,
+	ctx context.Context,
 ) (types.QueryInfo, http.Header, error) {
-	client := &http.Client{Timeout: 10 * 1000000000}
+	childCtx, span := c.tracer.Start(ctx, "HTTP request")
+	defer span.End()
+
+	client := &http.Client{
+		Timeout:   10 * 1000000000,
+		Transport: otelhttp.NewTransport(http.DefaultTransport),
+	}
 	start := time.Now()
 
 	queryInfo := types.QueryInfo{
@@ -35,7 +48,7 @@ func (c *Client) Get(
 		URL:     url,
 	}
 
-	req, err := http.NewRequest(http.MethodGet, url, nil)
+	req, err := http.NewRequestWithContext(childCtx, http.MethodGet, url, nil)
 	if err != nil {
 		return queryInfo, nil, err
 	}

pkg/queriers/balance.go

@@ -1,12 +1,16 @@
 package queriers
 
 import (
+	"context"
 	"main/pkg/config"
 	"main/pkg/tendermint"
 	"main/pkg/types"
 	"main/pkg/utils"
 	"sync"
 
+	"go.opentelemetry.io/otel/attribute"
+	"go.opentelemetry.io/otel/trace"
+
 	"github.com/prometheus/client_golang/prometheus"
 	"github.com/rs/zerolog"
 )
@@ -15,23 +19,32 @@ type BalanceQuerier struct {
 	Config *config.Config
 	Logger zerolog.Logger
 	RPCs   []*tendermint.RPC
+	Tracer trace.Tracer
 }
 
-func NewBalanceQuerier(config *config.Config, logger zerolog.Logger) *BalanceQuerier {
+func NewBalanceQuerier(
+	config *config.Config,
+	logger zerolog.Logger,
+	tracer trace.Tracer,
+) *BalanceQuerier {
 	rpcs := make([]*tendermint.RPC, len(config.Chains))
 
 	for index, chain := range config.Chains {
-		rpcs[index] = tendermint.NewRPC(chain, logger)
+		rpcs[index] = tendermint.NewRPC(chain, logger, tracer)
 	}
 
 	return &BalanceQuerier{
 		Config: config,
 		Logger: logger.With().Str("component", "balance_querier").Logger(),
 		RPCs:   rpcs,
+		Tracer: tracer,
 	}
 }
 
-func (q *BalanceQuerier) GetMetrics() ([]prometheus.Collector, []types.QueryInfo) {
+func (q *BalanceQuerier) GetMetrics(ctx context.Context) ([]prometheus.Collector, []types.QueryInfo) {
+	childCtx, span := q.Tracer.Start(ctx, "Querying balance metrics")
+	defer span.End()
+
 	balancesGauge := prometheus.NewGaugeVec(
 		prometheus.GaugeOpts{
 			Name: "cosmos_wallets_exporter_balance",
@@ -51,9 +64,14 @@ func (q *BalanceQuerier) GetMetrics() ([]prometheus.Collector, []types.QueryInfo
 		for _, wallet := range chain.Wallets {
 			wg.Add(1)
 			go func(wallet config.Wallet, chain config.Chain, rpc *tendermint.RPC) {
+				chainCtx, chainSpan := q.Tracer.Start(childCtx, "Querying chain and wallet")
+				chainSpan.SetAttributes(attribute.String("chain", chain.Name))
+				chainSpan.SetAttributes(attribute.String("wallet", wallet.Address))
+				defer chainSpan.End()
+
 				defer wg.Done()
 
-				balancesResponse, queryInfo, err := rpc.GetWalletBalances(wallet.Address)
+				balancesResponse, queryInfo, err := rpc.GetWalletBalances(wallet.Address, chainCtx)
 
 				mutex.Lock()
 				defer mutex.Unlock()