save ssz dummps during processing (#471)

beacon_chain/beacon_node.nim

@@ -373,6 +373,12 @@ proc sendAttestation(node: BeaconNode,
 
   node.network.broadcast(topicAttestations, attestation)
 
+  if node.config.dump:
+    SSZ.saveFile(
+      node.config.dumpDir / "att-" & $attestationData.slot & "-" &
+      $attestationData.index & "-" & validator.pubKey.shortLog &
+      ".ssz", attestation)
+
   info "Attestation sent",
     attestationData = shortLog(attestationData),
     validator = shortLog(validator),
@@ -482,6 +488,15 @@ proc proposeBlock(node: BeaconNode,
     validator = shortLog(validator),
     cat = "consensus"
 
+  if node.config.dump:
+    SSZ.saveFile(
+      node.config.dumpDir / "block-" & $newBlock.slot & "-" &
+      shortLog(newBlockRef.root) & ".ssz", newBlock)
+    SSZ.saveFile(
+      node.config.dumpDir / "state-" & $tmpState.data.slot & "-" &
+      shortLog(newBlockRef.root) & "-"  & shortLog(tmpState.root) & ".ssz",
+      tmpState.data)
+
   node.network.broadcast(topicBeaconBlocks, newBlock)
 
   beacon_blocks_proposed.inc()

beacon_chain/conf.nim

@@ -136,6 +136,11 @@ type
         desc: "Listening HTTP port of the metrics server."
         name: "metrics-server-port" }: uint16
 
+      dump* {.
+        defaultValue: false
+        desc: "Write SSZ dumps of blocks, attestations and states to data dir"
+        .}: bool
+
     of createTestnet:
       validatorsDir* {.
         desc: "Directory containing validator descriptors named 'vXXXXXXX.deposit.json'."
@@ -243,3 +248,6 @@ proc defaultDataDir*(conf: BeaconNodeConf): string =
 proc validatorFileBaseName*(validatorIdx: int): string =
   # there can apparently be tops 4M validators so we use 7 digits..
   fmt"v{validatorIdx:07}"
+
+func dumpDir*(conf: BeaconNodeConf): string =
+  conf.dataDir / "dump"

scripts/connect_to_testnet.nims

@@ -56,6 +56,7 @@ cli do (testnetName {.argument.}: string):
     dataDirName = testnetName.replace("/", "_")
     dataDir = buildDir / "data" / dataDirName
     validatorsDir = dataDir / "validators"
+    dumpDir = dataDir / "dump"
     beaconNodeBinary = buildDir / "beacon_node_" & dataDirName
     nimFlags = "-d:chronicles_log_level=DEBUG " & getEnv("NIM_PARAMS")
 
@@ -75,6 +76,8 @@ cli do (testnetName {.argument.}: string):
   cd rootDir
   exec &"""nim c {nimFlags} -d:"const_preset={preset}" -o:"{beaconNodeBinary}" beacon_chain/beacon_node.nim"""
 
+  mkDir dumpDir
+
   if depositContractOpt.len > 0 and not system.dirExists(validatorsDir):
     mode = Silent
     echo "Would you like to become a validator (you'll need access to 32 GoETH)? [Yn]"
@@ -101,6 +104,7 @@ cli do (testnetName {.argument.}: string):
   mode = Verbose
   exec replace(&"""{beaconNodeBinary}
     --data-dir="{dataDir}"
+    --dump=true
     --bootstrap-file="{testnetDir/bootstrapFile}"
     --state-snapshot="{testnetDir/genesisFile}" """ & depositContractOpt, "\n", " ")
 

tests/simulation/run_node.sh

@@ -44,6 +44,9 @@ if [[ $NODE_ID -lt $TOTAL_NODES ]]; then
   popd >/dev/null
 fi
 
+rm -rf "$DATA_DIR/dump"
+mkdir -p "$DATA_DIR/dump"
+
 $BEACON_NODE_BIN \
   --bootstrap-file=$BOOTSTRAP_ADDRESS_FILE \
   --data-dir=$DATA_DIR \