♻️ Implement initialization of fault detector

♻️ Update config and improve main.go

♻️ Multiple improvements based on feedback
- Improve usage of logging
- Fix incorrect go routine usage
- Improve app struct
- Install latest version of optimism for bindings

♻️ Apply feedback
- Add error to logs within the fault detector service
- Declare compiled regular expressions as var
- Fix the usage of quit channel for ticker
- Use uint64 for faultProofWindow and currentOutputIndex

♻️ Apply feedbacks
- Make regex vars private
- Declare quitTickerChan as struct

♻️ Create app struct and implement start/stop

.vscode/launch.json

@@ -0,0 +1,17 @@
+{
+    // Use IntelliSense to learn about possible attributes.
+    // Hover to view descriptions of existing attributes.
+    // For more information, visit: https://go.microsoft.com/fwlink/?linkid=830387
+    "version": "0.1.0",
+    "configurations": [
+        {
+            "name": "Run Fault Detector",
+            "type": "go",
+            "request": "launch",
+            "mode": "auto",
+            "program": "${workspaceRoot}/cmd",
+            "args": ["--config", "./config.yaml"],
+            "showLog": true
+        }
+    ]
+}

cmd/main.go

@@ -15,64 +15,124 @@ import (
 
 	"github.com/LiskHQ/op-fault-detector/pkg/api"
 	"github.com/LiskHQ/op-fault-detector/pkg/config"
+	"github.com/LiskHQ/op-fault-detector/pkg/faultdetector"
 	"github.com/LiskHQ/op-fault-detector/pkg/log"
 	"github.com/spf13/viper"
 )
 
-var apiServer *api.HTTPServer
+// App encapsulates start and stop logic for the whole application.
+type App struct {
+	ctx           context.Context
+	logger        log.Logger
+	errChan       chan error
+	config        *config.Config
+	wg            *sync.WaitGroup
+	apiServer     *api.HTTPServer
+	faultDetector *faultdetector.FaultDetector
+}
 
-func main() {
+// NewApp returns [App] with all the initialized services and variables.
+func NewApp(logger log.Logger) (*App, error) {
 	ctx, cancel := context.WithCancel(context.Background())
 	defer cancel()
 
-	logger, err := log.NewDefaultProductionLogger()
-	if err != nil {
-		panic(err)
-	}
-
 	configFilepath := flag.String("config", "./config.yaml", "Path to the config file")
 	flag.Parse()
 	config, err := getAppConfig(logger, *configFilepath)
 	if err != nil {
-		panic(err)
+		logger.Errorf("Failed at parsing config with error %w", err)
+		return nil, err
 	}
 
 	wg := sync.WaitGroup{}
+	errorChan := make(chan error, 1)
+
+	// Start Fault Detector
+	faultDetector, err := faultdetector.NewFaultDetector(
+		ctx,
+		logger,
+		errorChan,
+		&wg,
+		config.FaultDetectorConfig,
+	)
+	if err != nil {
+		logger.Errorf("Failed to create fault detector service.")
+		return nil, err
+	}
 
+	// Start API Server
+	apiServer := api.NewHTTPServer(ctx, logger, &wg, config, errorChan)
+
+	return &App{
+		ctx:           ctx,
+		logger:        logger,
+		errChan:       errorChan,
+		config:        config,
+		wg:            &wg,
+		apiServer:     apiServer,
+		faultDetector: faultDetector,
+	}, nil
+}
+
+// This will start the application by starting API Server and Fault Detector services.
+func (app *App) Start() {
 	doneChan := make(chan struct{})
 	signalChan := make(chan os.Signal, 1)
 	signal.Notify(signalChan, os.Interrupt, syscall.SIGTERM)
 
-	// Start Fault Detector
+	app.wg.Add(1)
+	go app.faultDetector.Start()
 
-	// Start API Server
-	serverChan := make(chan error, 1)
-	apiServer = api.NewHTTPServer(ctx, logger, &wg, config, serverChan)
-	wg.Add(1)
-	go apiServer.Start()
+	app.wg.Add(1)
+	go app.apiServer.Start()
 
 	go func() {
-		wg.Wait()
+		app.wg.Wait()
 		close(doneChan)
 	}()
 
 	for {
 		select {
 		case <-doneChan:
-			performCleanup(logger)
+			app.stop()
 			return
 
 		case <-signalChan:
-			performCleanup(logger)
+			app.stop()
 			return
 
-		case err := <-serverChan:
-			logger.Errorf("Received error of %v", err)
+		case err := <-app.errChan:
+			app.logger.Errorf("Received error of %v", err)
 			return
 		}
 	}
 }
 
+func (app *App) stop() {
+	app.faultDetector.Stop()
+	err := app.apiServer.Stop()
+	if err != nil {
+		app.logger.Error("Server shutdown not successful: %w", err)
+	}
+}
+
+func main() {
+	logger, err := log.NewDefaultProductionLogger()
+	if err != nil {
+		logger.Errorf("Failed to create logger, %w", err)
+		return
+	}
+
+	app, err := NewApp(logger)
+	if err != nil {
+		logger.Errorf("Failed to create app, %w", err)
+		return
+	}
+
+	logger.Infof("Starting app...")
+	app.Start()
+}
+
 // getAppConfig is the function that takes in the absolute path to the config file, parses the content and returns it.
 func getAppConfig(logger log.Logger, configFilepath string) (*config.Config, error) {
 	configDir := path.Dir(configFilepath)
@@ -104,10 +164,3 @@ func getAppConfig(logger log.Logger, configFilepath string) (*config.Config, err
 
 	return &config, nil
 }
-
-func performCleanup(logger log.Logger) {
-	err := apiServer.Stop()
-	if err != nil {
-		logger.Error("Server shutdown not successful: %w", err)
-	}
-}

config.yaml

@@ -13,3 +13,7 @@ api:
 
 # Faultdetector configurations
 fault_detector:
+  l1_rpc_endpoint: "https://rpc.notadegen.com/eth"
+  l2_rpc_endpoint: "https://mainnet.optimism.io/"
+  start_batch_index: 0
+  l2_output_oracle_contract_address: "0x0000000000000000000000000000000000000000"

go.mod

@@ -3,13 +3,13 @@ module github.com/LiskHQ/op-fault-detector
 go 1.21.5
 
 require (
-	github.com/ethereum-optimism/optimism/op-bindings v0.10.14
+	github.com/ethereum-optimism/optimism v1.4.2
 	github.com/ethereum/go-ethereum v1.13.10
 	github.com/gin-gonic/gin v1.9.1
 	github.com/magiconair/properties v1.8.7
 	github.com/spf13/viper v1.18.2
 	github.com/stretchr/testify v1.8.4
-	go.uber.org/multierr v1.10.0
+	go.uber.org/multierr v1.11.0
 	go.uber.org/zap v1.26.0
 )
 
@@ -25,7 +25,8 @@ require (
 	github.com/crate-crypto/go-kzg-4844 v0.7.0 // indirect
 	github.com/davecgh/go-spew v1.1.2-0.20180830191138-d8f796af33cc // indirect
 	github.com/deckarep/golang-set/v2 v2.1.0 // indirect
-	github.com/decred/dcrd/dcrec/secp256k1/v4 v4.0.1 // indirect
+	github.com/decred/dcrd/dcrec/secp256k1/v4 v4.2.0 // indirect
+	github.com/ethereum-optimism/superchain-registry/superchain v0.0.0-20231211205419-ff2e152c624f // indirect
 	github.com/ethereum/c-kzg-4844 v0.4.0 // indirect
 	github.com/fsnotify/fsnotify v1.7.0 // indirect
 	github.com/gabriel-vasile/mimetype v1.4.3 // indirect
@@ -35,7 +36,7 @@ require (
 	github.com/go-playground/universal-translator v0.18.1 // indirect
 	github.com/go-playground/validator/v10 v10.17.0 // indirect
 	github.com/goccy/go-json v0.10.2 // indirect
-	github.com/google/uuid v1.4.0 // indirect
+	github.com/google/uuid v1.5.0 // indirect
 	github.com/gorilla/websocket v1.5.0 // indirect
 	github.com/hashicorp/hcl v1.0.0 // indirect
 	github.com/holiman/uint256 v1.2.4 // indirect