Delay 10 seconds start + update watch command (#33)

.github/workflows/checks.yaml

@@ -24,7 +24,7 @@ jobs:
         run: go run main.go --output /tmp/playground & > /tmp/playground.log 2>&1
 
       - name: Validate that blocks are created
-        run: go run main.go validate
+        run: go run main.go watch-payloads --validate-payloads
 
       - name: Move playground logs
         if: ${{ failure() }}

README.md

@@ -41,7 +41,7 @@ Options:
 - `--output` (string): The directory where the chain data and artifacts are stored. It defaults to `$HOME/.playground/devnet`.
 - `--continue` (bool): Whether to restart the chain from a previous run if the output folder is not empty. It defaults to `false`.
 - `--use-bin-path` (bool): Whether to use the binaries from the local path instead of downloading them. It defaults to `false`.
-- `--genesis-delay` (int): The delay in seconds before the genesis block is created. It is used to account for the delay between the creation of the artifacts and the running of the services. It defaults to `5` seconds.
+- `--genesis-delay` (int): The delay in seconds before the genesis block is created. It is used to account for the delay between the creation of the artifacts and the running of the services. It defaults to `10` seconds.
 - `--electra`: (bool): If enabled, it enables the Electra fork at startup. It defaults to `false`.
 
 Unless the `--continue` flag is set, the playground will delete the output directory and start a new chain from scratch on every run.

main.go

@@ -97,15 +97,22 @@ var downloadArtifactsCmd = &cobra.Command{
 }
 
 var numBlocksValidate uint64
+var validatePayloads bool
 
-var validateCmd = &cobra.Command{
-	Use:  "validate",
-	Long: `Validate the playground`,
+var watchCmd = &cobra.Command{
+	Use:  "watch-payloads",
+	Long: `Watch the payload attribute events`,
 	RunE: func(cmd *cobra.Command, args []string) error {
 		// Test that blocks are being produced
 		log := mevRCommon.LogSetup(false, "info")
 		clt := beaconclient.NewProdBeaconInstance(log, "http://localhost:3500", "http://localhost:3500")
 
+		// Subscribe to head events right away even if the connection has not been established yet
+		// That is handled internally in the function already.
+		// Otherwise, if we connect only when the first head slot happens we might miss some initial slots.
+		ch := make(chan beaconclient.PayloadAttributesEvent)
+		go clt.SubscribeToPayloadAttributesEvents(ch)
+
 		{
 			// If the chain has not started yet, wait for it to start.
 			// Otherwise, the subscription will not return any data.
@@ -118,7 +125,7 @@ var validateCmd = &cobra.Command{
 				if err != nil {
 					return false
 				}
-				return sync.HeadSlot > 1
+				return sync.HeadSlot >= 1
 			}
 
 			if !isReady() {
@@ -139,49 +146,73 @@ var validateCmd = &cobra.Command{
 
 		log.Infof("Chain is alive. Subscribing to head events")
 
-		ch := make(chan beaconclient.HeadEventData)
-		go clt.SubscribeToHeadEvents(ch)
-
 		var lastSlot uint64
-		for i := uint64(0); i < numBlocksValidate; i++ {
+		for {
 			select {
 			case head := <-ch:
-				if lastSlot != 0 && lastSlot+1 != head.Slot {
-					return fmt.Errorf("slot mismatch, expected %d, got %d", lastSlot+1, head.Slot)
+				log.Infof("Slot: %d Parent block number: %d", head.Data.ProposalSlot, head.Data.ParentBlockNumber)
+
+				if validatePayloads {
+					// If we are being notified of a new slot, validate that the slots are contiguous
+					// Note that lighthouse might send multiple updates for the same slot.
+					if lastSlot != 0 && lastSlot != head.Data.ProposalSlot && lastSlot+1 != head.Data.ProposalSlot {
+						return fmt.Errorf("slot mismatch, expected %d, got %d", lastSlot+1, head.Data.ProposalSlot)
+					}
+					// if the network did not miss any initial slots, lighthouse will send payload attribute updates
+					// of the form: (slot = slot, parent block number = slot - 2), (slot, slot - 1).
+					// The -2 is in case we want to handle reorgs in the chain.
+					// We need to validate that at least the difference between the parent block number and the slot is 2.
+					if head.Data.ProposalSlot-head.Data.ParentBlockNumber > 2 {
+						return fmt.Errorf("parent block too big %d", head.Data.ParentBlockNumber)
+					}
+
+					if lastSlot != head.Data.ProposalSlot {
+						numBlocksValidate--
+						if numBlocksValidate == 0 {
+							return nil
+						}
+					}
 				}
 
-				log.Infof("Slot: %d Block: %s", head.Slot, head.Block)
-				lastSlot = head.Slot
+				lastSlot = head.Data.ProposalSlot
 			case <-time.After(20 * time.Second):
 				return fmt.Errorf("timeout waiting for block")
 			}
 		}
-
-		return nil
 	},
 }
 
+// minimumGenesisDelay is the minimum delay for the genesis time. This is required
+// because lighthouse takes some time to start and we need to make sure it is ready
+// otherwise, some blocks are missed.
+var minimumGenesisDelay uint64 = 10
+
 func main() {
 	rootCmd.Flags().StringVar(&outputFlag, "output", "", "")
 	rootCmd.Flags().BoolVar(&continueFlag, "continue", false, "")
 	rootCmd.Flags().BoolVar(&useBinPathFlag, "use-bin-path", false, "")
-	rootCmd.Flags().Uint64Var(&genesisDelayFlag, "genesis-delay", 5, "")
+	rootCmd.Flags().Uint64Var(&genesisDelayFlag, "genesis-delay", minimumGenesisDelay, "")
 	rootCmd.Flags().BoolVar(&latestForkFlag, "electra", false, "")
 	rootCmd.Flags().BoolVar(&useRethForValidation, "use-reth-for-validation", false, "enable flashbots_validateBuilderSubmissionV* on reth and use them for validation")
 	rootCmd.Flags().Uint64Var(&secondaryBuilderPort, "secondary", 1234, "port to use for the secondary builder")
 
 	downloadArtifactsCmd.Flags().BoolVar(&validateFlag, "validate", false, "")
-	validateCmd.Flags().Uint64Var(&numBlocksValidate, "num-blocks", 5, "")
+	watchCmd.Flags().Uint64Var(&numBlocksValidate, "validate-num-blocks", 5, "")
+	watchCmd.Flags().BoolVar(&validatePayloads, "validate-payloads", false, "")
 
 	rootCmd.AddCommand(downloadArtifactsCmd)
-	rootCmd.AddCommand(validateCmd)
+	rootCmd.AddCommand(watchCmd)
 	if err := rootCmd.Execute(); err != nil {
 		fmt.Println(err)
 		os.Exit(1)
 	}
 }
 
 func runIt() error {
+	if genesisDelayFlag < minimumGenesisDelay {
+		return fmt.Errorf("genesis delay must be at least %d", minimumGenesisDelay)
+	}
+
 	if outputFlag == "" {
 		// Use the $HOMEDIR/devnet as the default output
 		homeDir, err := getHomeDir()