feat(cmd): Run serve from root command and support url args

cmd/root.go

@@ -15,14 +15,24 @@ import (
 var rootCmd = &cobra.Command{
 	Use:   "ethereum-metrics-exporter",
 	Short: "A tool to report the sync status of ethereum nodes",
+	Run: func(cmd *cobra.Command, args []string) {
+		initCommon()
+
+		err := ethClient.Serve(ctx, metricsPort)
+		if err != nil {
+			logr.Fatal(err)
+		}
+	},
 }
 
 var (
-	cfgFile   string
-	config    *exporter.Config
-	ethClient exporter.Ethereum
-	ctx       context.Context
-	logr      logrus.FieldLogger
+	cfgFile      string
+	config       *exporter.Config
+	ethClient    exporter.Ethereum
+	ctx          context.Context
+	logr         logrus.FieldLogger
+	executionUrl string
+	consensusUrl string
 )
 
 // Execute adds all child commands to the root command and sets flags appropriately.
@@ -42,6 +52,10 @@ func init() {
 
 	rootCmd.PersistentFlags().StringVar(&cfgFile, "config", "", "config file (default is $HOME/.ethereum-metrics-exporter.yaml)")
 
+	rootCmd.PersistentFlags().IntVarP(&metricsPort, "metrics-port", "", 9090, "Port to serve Prometheus metrics on")
+	rootCmd.PersistentFlags().StringVarP(&executionUrl, "execution-url", "", "", "(optional) URL to the execution node")
+	rootCmd.PersistentFlags().StringVarP(&consensusUrl, "consensus-url", "", "", "(optional) URL to the consensus node")
+
 	// Cobra also supports local flags, which will only run
 	// when this action is called directly.
 	rootCmd.Flags().BoolP("toggle", "t", false, "Help message for toggle")
@@ -77,6 +91,16 @@ func initCommon() {
 		logr.Fatal(err)
 	}
 
+	if executionUrl != "" {
+		config.Execution.Enabled = true
+		config.Execution.URL = executionUrl
+	}
+
+	if consensusUrl != "" {
+		config.Consensus.Enabled = true
+		config.Consensus.URL = consensusUrl
+	}
+
 	ethClient = exporter.NewEthereum(log, config)
 	if err := ethClient.Init(ctx); err != nil {
 		logrus.Fatal(err)

cmd/serve.go

@@ -29,7 +29,4 @@ var serveCmd = &cobra.Command{
 
 func init() {
 	rootCmd.AddCommand(serveCmd)
-
-	serveCmd.Flags().BoolVarP(&exitWhenSynced, "exit-when-synced", "", false, "Exit the program when both clients are synced")
-	serveCmd.Flags().IntVarP(&metricsPort, "metrics-port", "", 9090, "Port to serve Prometheus metrics on")
 }

example_config.yaml

@@ -2,7 +2,7 @@ pollingFrequencySeconds: 5
 
 consensus:
   enabled: true
-  url: "http://192.168.0.128:5052"
+  url: "http://192.168.0.128:5053"
   name: "consensus-client"
 execution:
   enabled: true

pkg/exporter/consensus/consensus.go

@@ -2,6 +2,7 @@ package consensus
 
 import (
 	"context"
+	"errors"
 
 	eth2client "github.com/attestantio/go-eth2-client"
 	"github.com/attestantio/go-eth2-client/http"
@@ -11,12 +12,13 @@ import (
 
 type Node interface {
 	Name() string
+	URL() string
 	SyncStatus(ctx context.Context) (*SyncStatus, error)
 }
 
 type node struct {
 	name    string
-	URL     string
+	url     string
 	client  eth2client.Service
 	log     logrus.FieldLogger
 	metrics Metrics
@@ -33,7 +35,7 @@ func NewConsensusNode(ctx context.Context, log logrus.FieldLogger, name string,
 
 	return &node{
 		name:    name,
-		URL:     url,
+		url:     url,
 		client:  client,
 		log:     log,
 		metrics: metrics,
@@ -44,8 +46,30 @@ func (c *node) Name() string {
 	return c.name
 }
 
+func (c *node) URL() string {
+	return c.url
+}
+
+func (c *node) refreshClient(ctx context.Context) error {
+	client, err := http.New(ctx,
+		http.WithAddress(c.url),
+		http.WithLogLevel(zerolog.WarnLevel),
+	)
+	if err != nil {
+		return err
+	}
+
+	c.client = client
+	return nil
+}
+
 func (c *node) SyncStatus(ctx context.Context) (*SyncStatus, error) {
-	provider := c.client.(eth2client.NodeSyncingProvider)
+	provider, isProvider := c.client.(eth2client.NodeSyncingProvider)
+	if !isProvider {
+		c.refreshClient(ctx)
+		return nil, errors.New("client does not implement eth2client.NodeSyncingProvider")
+	}
+
 	status, err := provider.NodeSyncing(ctx)
 	if err != nil {
 		return nil, err

pkg/exporter/ethereum.go

@@ -73,7 +73,10 @@ func (e *ethereum) ticker(ctx context.Context) {
 
 func (e *ethereum) Serve(ctx context.Context, port int) error {
 	go e.ticker(ctx)
-	e.log.Info(fmt.Sprintf("Starting metrics server on :%v", port))
+	e.log.
+		WithField("consensus_url", e.consensus.URL()).
+		WithField("execution_url", e.execution.URL()).
+		Info(fmt.Sprintf("Starting metrics server on :%v", port))
 
 	http.Handle("/metrics", promhttp.Handler())
 	err := http.ListenAndServe(fmt.Sprintf(":%v", port), nil)

pkg/exporter/execution/execution.go

@@ -9,12 +9,13 @@ import (
 
 type Node interface {
 	Name() string
+	URL() string
 	SyncStatus(ctx context.Context) (*SyncStatus, error)
 }
 
 type node struct {
 	name    string
-	URL     string
+	url     string
 	client  ethclient.Client
 	log     logrus.FieldLogger
 	metrics Metrics
@@ -27,7 +28,7 @@ func NewExecutionNode(ctx context.Context, log logrus.FieldLogger, name string,
 
 	return &node{
 		name:    name,
-		URL:     url,
+		url:     url,
 		client:  *client,
 		log:     log,
 		metrics: metrics,
@@ -38,6 +39,10 @@ func (e *node) Name() string {
 	return e.name
 }
 
+func (e *node) URL() string {
+	return e.url
+}
+
 func (e *node) SyncStatus(ctx context.Context) (*SyncStatus, error) {
 	status, err := e.client.SyncProgress(ctx)
 	if err != nil {