feat(server/v2): wire telemetry + server refactors

server/v2/api/grpc/config.go

@@ -4,14 +4,9 @@ import "math"
 
 func DefaultConfig() *Config {
 	return &Config{
-		Enable: true,
-		// DefaultGRPCAddress defines the default address to bind the gRPC server to.
-		Address: "localhost:9090",
-		// DefaultGRPCMaxRecvMsgSize defines the default gRPC max message size in
-		// bytes the server can receive.
+		Enable:         true,
+		Address:        "localhost:9090",
 		MaxRecvMsgSize: 1024 * 1024 * 10,
-		// DefaultGRPCMaxSendMsgSize defines the default gRPC max message size in
-		// bytes the server can send.
 		MaxSendMsgSize: math.MaxInt32,
 	}
 }

server/v2/api/grpcgateway/server.go

@@ -17,7 +17,10 @@ import (
 	serverv2 "cosmossdk.io/server/v2"
 )
 
-var _ serverv2.ServerComponent[transaction.Tx] = (*GRPCGatewayServer[transaction.Tx])(nil)
+var (
+	_ serverv2.ServerComponent[transaction.Tx] = (*GRPCGatewayServer[transaction.Tx])(nil)
+	_ serverv2.HasConfig                       = (*GRPCGatewayServer[transaction.Tx])(nil)
+)
 
 const (
 	ServerName = "grpc-gateway"

server/v2/api/telemetry/config.go

@@ -1,13 +1,32 @@
 package telemetry
 
-type Config struct {
-	// Prefixed with keys to separate services
-	ServiceName string `mapstructure:"service-name" toml:"service-name" comment:"Prefixed with keys to separate services."`
+func DefaultConfig() *Config {
+	return &Config{
+		Enable:                  true,
+		Address:                 "localhost:1338",
+		ServiceName:             "",
+		EnableHostname:          false,
+		EnableHostnameLabel:     false,
+		EnableServiceLabel:      false,
+		PrometheusRetentionTime: 0,
+		GlobalLabels:            nil,
+		MetricsSink:             "",
+		StatsdAddr:              "",
+		DatadogHostname:         "",
+	}
+}
 
-	// Enabled enables the application telemetry functionality. When enabled,
+type Config struct {
+	// Enable enables the application telemetry functionality. When enabled,
 	// an in-memory sink is also enabled by default. Operators may also enabled
 	// other sinks such as Prometheus.
-	Enabled bool `mapstructure:"enabled" toml:"enabled" comment:"Enabled enables the application telemetry functionality. When enabled, an in-memory sink is also enabled by default. Operators may also enabled other sinks such as Prometheus."`
+	Enable bool `mapstructure:"enable" toml:"enable" comment:"Enable enables the application telemetry functionality. When enabled, an in-memory sink is also enabled by default. Operators may also enabled other sinks such as Prometheus."`
+
+	// Address defines the API server to listen on
+	Address string `mapstructure:"address" toml:"address" comment:"Address defines the metrics server address to bind to."`
+
+	// Prefixed with keys to separate services
+	ServiceName string `mapstructure:"service-name" toml:"service-name" comment:"Prefixed with keys to separate services."`
 
 	// Enable prefixing gauge values with hostname
 	EnableHostname bool `mapstructure:"enable-hostname" toml:"enable-hostname" comment:"Enable prefixing gauge values with hostname."`

server/v2/api/telemetry/metrics.go

@@ -58,11 +58,7 @@ type GatherResponse struct {
 }
 
 // New creates a new instance of Metrics
-func New(cfg Config) (_ *Metrics, rerr error) {
-	if !cfg.Enabled {
-		return nil, nil
-	}
-
+func NewMetrics(cfg *Config) (*Metrics, error) {
 	if numGlobalLabels := len(cfg.GlobalLabels); numGlobalLabels > 0 {
 		parsedGlobalLabels := make([]metrics.Label, numGlobalLabels)
 		for i, gl := range cfg.GlobalLabels {
@@ -89,12 +85,11 @@ func New(cfg Config) (_ *Metrics, rerr error) {
 		sink = memSink
 		inMemSig := metrics.DefaultInmemSignal(memSink)
 		defer func() {
-			if rerr != nil {
+			if err != nil {
 				inMemSig.Stop()
 			}
 		}()
 	}
-
 	if err != nil {
 		return nil, err
 	}

server/v2/api/telemetry/server.go

@@ -1,47 +1,127 @@
 package telemetry
 
 import (
+	"context"
 	"encoding/json"
 	"fmt"
 	"net/http"
 	"strings"
 
-	"github.com/gorilla/mux"
+	"cosmossdk.io/core/transaction"
+	"cosmossdk.io/log"
+	serverv2 "cosmossdk.io/server/v2"
 )
 
-func RegisterMetrics(r mux.Router, cfg Config) (*Metrics, error) {
-	m, err := New(cfg)
+var (
+	_ serverv2.ServerComponent[transaction.Tx] = (*TelemetryServer[transaction.Tx])(nil)
+	_ serverv2.HasConfig                       = (*TelemetryServer[transaction.Tx])(nil)
+)
+
+const ServerName = "telemetry"
+
+type TelemetryServer[T transaction.Tx] struct {
+	config  *Config
+	logger  log.Logger
+	server  *http.Server
+	metrics *Metrics
+}
+
+// New creates a new telemetry server.
+func New[T transaction.Tx]() *TelemetryServer[T] {
+	return &TelemetryServer[T]{}
+}
+
+// Name returns the server name.
+func (s *TelemetryServer[T]) Name() string {
+	return ServerName
+}
+
+func (s *TelemetryServer[T]) Config() any {
+	if s.config == nil || s.config == (&Config{}) {
+		return DefaultConfig()
+	}
+
+	return s.config
+}
+
+// Init implements serverv2.ServerComponent.
+func (s *TelemetryServer[T]) Init(appI serverv2.AppI[T], cfg map[string]any, logger log.Logger) error {
+	serverCfg := s.Config().(*Config)
+	if len(cfg) > 0 {
+		if err := serverv2.UnmarshalSubConfig(cfg, s.Name(), &serverCfg); err != nil {
+			return fmt.Errorf("failed to unmarshal config: %w", err)
+		}
+	}
+	s.config = serverCfg
+	s.logger = logger
+
+	metrics, err := NewMetrics(s.config)
 	if err != nil {
-		return nil, err
+		return fmt.Errorf("failed to initialize metrics: %w", err)
 	}
+	s.metrics = metrics
 
-	metricsHandler := func(w http.ResponseWriter, r *http.Request) {
-		format := strings.TrimSpace(r.FormValue("format"))
+	return nil
+}
 
-		gr, err := m.Gather(format)
-		if err != nil {
-			w.Header().Set("Content-Type", "application/json")
-			w.WriteHeader(http.StatusBadRequest)
-			bz, err := json.Marshal(errorResponse{Code: 400, Error: fmt.Sprintf("failed to gather metrics: %s", err)})
-			if err != nil {
-				return
-			}
-			_, _ = w.Write(bz)
+func (s *TelemetryServer[T]) Start(ctx context.Context) error {
+	if !s.config.Enable {
+		return nil
+	}
 
-			return
-		}
+	mux := http.NewServeMux()
+	mux.HandleFunc("/", s.metricsHandler)
+	// keeping /metrics for backwards compatibility
+	mux.HandleFunc("/metrics", func(w http.ResponseWriter, r *http.Request) {
+		http.Redirect(w, r, "/", http.StatusMovedPermanently)
+	})
 
-		w.Header().Set("Content-Type", gr.ContentType)
-		_, _ = w.Write(gr.Metrics)
+	s.server = &http.Server{
+		Addr:    s.config.Address,
+		Handler: mux,
 	}
 
-	r.HandleFunc("/metrics", metricsHandler).Methods("GET")
+	go func() {
+		s.logger.Info("Starting telemetry server", "address", s.config.Address)
+		if err := s.server.ListenAndServe(); err != nil && err != http.ErrServerClosed {
+			s.logger.Error("Failed to start telemetry server", "error", err)
+		}
+	}()
 
-	return m, nil
+	return nil
 }
 
-// errorResponse defines the attributes of a JSON error response.
-type errorResponse struct {
-	Code  int    `json:"code,omitempty"`
-	Error string `json:"error"`
+func (s *TelemetryServer[T]) Stop(ctx context.Context) error {
+	if !s.config.Enable || s.server == nil {
+		return nil
+	}
+
+	s.logger.Info("Stopping telemetry server")
+	return s.server.Shutdown(ctx)
+}
+
+func (s *TelemetryServer[T]) metricsHandler(w http.ResponseWriter, r *http.Request) {
+	format := strings.TrimSpace(r.FormValue("format"))
+
+	// errorResponse defines the attributes of a JSON error response.
+	type errorResponse struct {
+		Code  int    `json:"code,omitempty"`
+		Error string `json:"error"`
+	}
+
+	gr, err := s.metrics.Gather(format)
+	if err != nil {
+		w.Header().Set("Content-Type", "application/json")
+		w.WriteHeader(http.StatusBadRequest)
+		bz, err := json.Marshal(errorResponse{Code: 400, Error: fmt.Sprintf("failed to gather metrics: %s", err)})
+		if err != nil {
+			return
+		}
+		_, _ = w.Write(bz)
+
+		return
+	}
+
+	w.Header().Set("Content-Type", gr.ContentType)
+	_, _ = w.Write(gr.Metrics)
 }

simapp/v2/simdv2/cmd/commands.go

@@ -15,6 +15,7 @@ import (
 	runtimev2 "cosmossdk.io/runtime/v2"
 	serverv2 "cosmossdk.io/server/v2"
 	"cosmossdk.io/server/v2/api/grpc"
+	"cosmossdk.io/server/v2/api/telemetry"
 	"cosmossdk.io/server/v2/cometbft"
 	"cosmossdk.io/server/v2/store"
 	"cosmossdk.io/simapp/v2"
@@ -81,6 +82,7 @@ func initRootCmd[T transaction.Tx](
 		),
 		grpc.New[T](),
 		store.New[T](newApp),
+		telemetry.New[T](),
 	); err != nil {
 		panic(err)
 	}