Chain creation and network simulation start script

beacon_chain/beacon_chain_db.nim

@@ -16,13 +16,16 @@ proc init*(T: type BeaconChainDB, dataDir: string): BeaconChainDB =
 
 proc lastFinalizedState*(db: BeaconChainDB): BeaconStateRef =
   try:
-    var stateJson = parseJson readFile(db.dataRoot / "BeaconState.json")
-    # TODO implement this
+    let stateFile = db.dataRoot / "BeaconState.json"
+    if fileExists stateFile:
+      new result
+      Json.loadFile(stateFile, result[])
   except:
+    error "Failed to load the latest finalized state",
+          err = getCurrentExceptionMsg()
     return nil
 
 proc persistBlock*(db: BeaconChainDB, s: BeaconState, b: BeaconBlock) =
-  let stateJson = StringJsonWriter.encode(s, pretty = true)
-  writeFile(db.dataRoot / "BeaconState.json", stateJson)
+  Json.saveFile(db.dataRoot / "BeaconState.json", s, pretty = true)
   debug "State persisted"
 

beacon_chain/beacon_node.nim

@@ -1,8 +1,8 @@
 import
-  os, net, sequtils,
+  std_shims/os_shims, net, sequtils, options,
   asyncdispatch2, chronicles, confutils, eth_p2p, eth_keys,
-  spec/[beaconstate, datatypes, helpers, crypto], conf, time, fork_choice, ssz,
-  beacon_chain_db, validator_pool, mainchain_monitor,
+  spec/[beaconstate, datatypes, helpers, crypto, digest], conf, time,
+  fork_choice, ssz, beacon_chain_db, validator_pool, mainchain_monitor,
   sync_protocol, gossipsub_protocol, trusted_state_snapshots
 
 type
@@ -34,6 +34,7 @@ proc ensureNetworkKeys*(dataDir: string): KeyPair =
 proc init*(T: type BeaconNode, conf: BeaconNodeConf): T =
   new result
   result.config = conf
+
   result.db = BeaconChainDB.init(string conf.dataDir)
   result.keys = ensureNetworkKeys(string conf.dataDir)
 
@@ -41,12 +42,35 @@ proc init*(T: type BeaconNode, conf: BeaconNodeConf): T =
   address.ip = parseIpAddress("0.0.0.0")
   address.tcpPort = Port(conf.tcpPort)
   address.udpPort = Port(conf.udpPort)
+
   result.network = newEthereumNode(result.keys, address, 0, nil, clientId)
 
+  writeFile(string(conf.dataDir) / "beacon_node.address",
+            $result.network.listeningAddress)
+
+proc connectToNetwork(node: BeaconNode) {.async.} =
+  var bootstrapNodes = newSeq[ENode]()
+
+  for node in node.config.bootstrapNodes:
+    bootstrapNodes.add initENode(node)
+
+  let bootstrapFile = string node.config.bootstrapNodesFile
+  if bootstrapFile.len > 0:
+    for ln in lines(bootstrapFile):
+      bootstrapNodes.add initENode(string ln)
+
+  if bootstrapNodes.len > 0:
+    await node.network.connectToNetwork(bootstrapNodes)
+  else:
+    node.network.startListening()
+
 proc sync*(node: BeaconNode): Future[bool] {.async.} =
   let persistedState = node.db.lastFinalizedState()
   if persistedState.isNil or
      persistedState[].slotDistanceFromNow() > WEAK_SUBJECTVITY_PERIOD:
+    if node.config.stateSnapshot.isSome:
+      node.beaconState = node.config.stateSnapshot.get
+    else:
       node.beaconState = await obtainTrustedStateSnapshot(node.db)
   else:
     node.beaconState = persistedState[]
@@ -76,22 +100,19 @@ template findIt(s: openarray, predicate: untyped): int =
   res
 
 proc addLocalValidators*(node: BeaconNode) =
-  for validator in node.config.validatorKeys:
-    # 1. Parse the validator keys
-    let privKey = loadPrivKey(validator)
-    let pubKey = privKey.pubKey()
-    let randao = loadRandao(validator)
+  for validator in node.config.validators:
+    let
+      privKey = validator.privKey
+      pubKey = privKey.pubKey()
+      randao = validator.randao
 
-    # 2. Check whether the validators exist in the beacon state.
-    #    (Report a warning otherwise)
     let idx = node.beaconState.validator_registry.findIt(it.pubKey == pubKey)
     if idx == -1:
       warn "Validator not in registry", pubKey
     else:
-      # 3. Add the validators to node.attachedValidators
-      # TODO: Parse randao secret
       node.attachedValidators.addLocalValidator(idx, pubKey, privKey, randao)
 
+    info "Local validators attached ", count = node.attachedValidators.count
 
 proc getAttachedValidator(node: BeaconNode, idx: int): AttachedValidator =
   let validatorKey = node.beaconState.validator_registry[idx].pubkey
@@ -198,10 +219,33 @@ proc processBlocks*(node: BeaconNode) {.async.} =
     # Attestations are verified as aggregated groups
     node.attestations.add(getAttestationCandidate a, node.beaconState)
 
+var gPidFile: string
+proc createPidFile(filename: string) =
+  createDir splitFile(filename).dir
+  writeFile filename, $getCurrentProcessId()
+  gPidFile = filename
+  addQuitProc proc {.noconv.} = removeFile gPidFile
+
 when isMainModule:
   let config = BeaconNodeConf.load()
+  case config.cmd
+  of createChain:
+    let outfile = string config.outputStateFile
+    let initialState = get_initial_beacon_state(
+      config.chainStartupData.validatorDeposits,
+      config.chainStartupData.genesisTime,
+      Eth2Digest())
+    
+    Json.saveFile(outfile, initialState, pretty = true)
+    echo "Wrote ", outfile
+    quit 0
+
+  of noCommand:
     waitFor syncrhronizeClock()
+    createPidFile(string(config.dataDir) / "beacon_node.pid")
+
     var node = BeaconNode.init config
+    waitFor node.connectToNetwork()
 
     if not waitFor node.sync():
       quit 1

beacon_chain/conf.nim

@@ -1,18 +1,46 @@
 import
-  confutils/defs, spec/crypto, milagro_crypto, randao
+  os, options,
+  confutils/defs, milagro_crypto, json_serialization,
+  spec/[crypto, datatypes], randao, time
+
+export
+  json_serialization
 
 type
   ValidatorKeyPath* = distinct string
 
+  StartUpCommand* = enum
+    noCommand
+    createChain
+
+  ChainStartupData* = object
+    validatorDeposits*: seq[Deposit]
+    genesisTime*: Timestamp
+
+  PrivateValidatorData* = object
+    privKey*: ValidatorPrivKey
+    randao*: Randao
+
   BeaconNodeConf* = object
+    case cmd* {.
+      command
+      defaultValue: noCommand.}: StartUpCommand
+
+    of noCommand:
       dataDir* {.
-      desc: "The directory where nimbus will store all blockchain data.",
-      shorthand: "d",
+        desc: "The directory where nimbus will store all blockchain data."
+        shortform: "d"
         defaultValue: getConfigDir() / "nimbus".}: DirPath
 
       bootstrapNodes* {.
-      desc: "Specifies one or more bootstrap nodes to use when connecting to the network.",
-      shorthand: "b".}: seq[string]
+        desc: "Specifies one or more bootstrap nodes to use when connecting to the network."
+        longform: "bootstrapNode"
+        shortform: "b".}: seq[string]
+
+      bootstrapNodesFile* {.
+        desc: "Specifies a line-delimited file of bootsrap Ethereum network addresses"
+        shortform: "f"
+        defaultValue: "".}: FilePath
 
       tcpPort* {.
         desc: "TCP listening port".}: int
@@ -20,10 +48,26 @@ type
       udpPort* {.
         desc: "UDP listening port".}: int
 
-    validatorKeys* {.
+      validators* {.
+        required
         desc: "A path to a pair of public and private keys for a validator. " &
-            "Nimbus will automatically add the extensions .privkey and .pubkey.",
-      shorthand: "v".}: seq[ValidatorKeyPath]
+              "Nimbus will automatically add the extensions .privkey and .pubkey."
+        longform: "validator"
+        shortform: "v".}: seq[PrivateValidatorData]
+
+      stateSnapshot* {.
+        desc: "Json file specifying a recent state snapshot"
+        shortform: "s".}: Option[BeaconState]
+
+    of createChain:
+      chainStartupData* {.
+        desc: ""
+        shortform: "c".}: ChainStartupData
+
+      outputStateFile* {.
+        desc: "Output file where to write the initial state snapshot"
+        longform: "out"
+        shortform: "o".}: OutFilePath
 
 proc readFileBytes(path: string): seq[byte] =
   cast[seq[byte]](readFile(path))
@@ -34,8 +78,21 @@ proc loadPrivKey*(p: ValidatorKeyPath): ValidatorPrivKey =
 proc loadRandao*(p: ValidatorKeyPath): Randao =
   initRandao(readFileBytes(string(p) & ".randao"))
 
-proc parse*(T: type ValidatorKeyPath, input: TaintedString): T =
+proc parseCmdArg*(T: type ValidatorKeyPath, input: TaintedString): T =
   result = T(input)
   discard loadPrivKey(result)
   discard loadRandao(result)
 
+template mustBeFilePath(input: TaintedString) =
+  if not fileExists(string input):
+    raise newException(ValueError, "")
+
+template handledAsJsonFilename(T: untyped) {.dirty.} =
+  proc parseCmdArg*(_: type T, input: TaintedString): T =
+    input.mustBeFilePath
+    return Json.loadFile(string(input), T)
+
+handledAsJsonFilename BeaconState
+handledAsJsonFilename ChainStartupData
+handledAsJsonFilename PrivateValidatorData
+

beacon_chain/randao.nim

@@ -1,7 +1,7 @@
 import spec/[digest, helpers]
 
 type Randao* = object
-  seed: Eth2Digest
+  seed*: Eth2Digest
 
 const MaxRandaoLevels = 10000 # TODO: This number is arbitrary
 

beacon_chain/spec/crypto.nim

@@ -10,8 +10,11 @@
 # hashed out. This layer helps isolate those chagnes.
 
 import
-  milagro_crypto, hashes
-export milagro_crypto.`$`
+  hashes,
+  milagro_crypto, json_serialization
+
+export
+  json_serialization, milagro_crypto.`$`
 
 type
   ValidatorPubKey* = milagro_crypto.VerKey
@@ -38,3 +41,22 @@ func bls_verify*(
   # name from spec!
   # TODO domain!
   sig.verifyMessage(msg, pubkey)
+
+proc writeValue*(writer: var JsonWriter, value: ValidatorPubKey) {.inline.} =
+  writer.writeValue $value
+
+proc readValue*(reader: var JsonReader, value: var ValidatorPubKey) {.inline.} =
+  value = initVerKey reader.readValue(string)
+
+proc writeValue*(writer: var JsonWriter, value: ValidatorSig) {.inline.} =
+  writer.writeValue $value
+
+proc readValue*(reader: var JsonReader, value: var ValidatorSig) {.inline.} =
+  value = initSignature reader.readValue(string)
+
+proc writeValue*(writer: var JsonWriter, value: ValidatorPrivKey) {.inline.} =
+  writer.writeValue $value
+
+proc readValue*(reader: var JsonReader, value: var ValidatorPrivKey) {.inline.} =
+  value = initSigKey reader.readValue(string)
+

beacon_chain/spec/datatypes.nim

@@ -392,8 +392,8 @@ type
 
 when true:
   # TODO: Remove these once RLP serialization is no longer used
-  import nimcrypto, rlp
-  export append, read
+  import nimcrypto, rlp, json_serialization
+  export append, read, json_serialization
 
   proc append*(rlpWriter: var RlpWriter, value: ValidatorPubKey) =
     discard
@@ -412,3 +412,5 @@ when true:
 
   proc read*(rlp: var Rlp, T: type ValidatorSig): T {.inline.} =
     discard
+
+

beacon_chain/spec/digest.nim

@@ -20,9 +20,11 @@
 # In our code base, to enable a smooth transition, we call this function
 # `eth2hash`, and it outputs a `Eth2Digest`. Easy to sed :)
 
-import nimcrypto/[blake2, hash]
+import
+  nimcrypto/[blake2, hash], eth_common/eth_types_json_serialization
 
-export hash.`$`
+export
+  eth_types_json_serialization, hash.`$`
 
 type
   Eth2Digest* = MDigest[32 * 8] ## `hash32` from spec

beacon_chain/time.nim

@@ -4,11 +4,13 @@ import
   spec/datatypes
 
 type
-  Timestamp = uint64 # Unix epoch timestamp in millisecond resolution
+  Timestamp* = uint64 # Unix epoch timestamp in millisecond resolution
 
 var
   detectedClockDrift: int64
 
+template now*: auto = fastEpochTime()
+
 proc timeSinceGenesis*(s: BeaconState): Timestamp =
   Timestamp(int64(fastEpochTime() - s.genesis_time * 1000) -
             detectedClockDrift)

beacon_chain/validator_keygen.nim

@@ -1,36 +1,73 @@
-import os, ospaths, milagro_crypto, nimcrypto, ./spec/digest
+import
+  os, ospaths, strutils, strformat,
+  milagro_crypto, nimcrypto, json_serialization,
+  spec/[datatypes, digest, crypto], conf, randao, time, ssz,
+  ../tests/testutil
 
-proc writeFile(filename: string, content: openarray[byte]) =
-  var s = newString(content.len)
-  if content.len != 0:
-    copyMem(addr s[0], unsafeAddr content[0], content.len)
-  writeFile(filename, s)
+proc writeFile(filename: string, value: auto) =
+  Json.saveFile(filename, value, pretty = true)
+  echo &"Wrote {filename}"
 
-proc genKeys(path: string) =
-  let pk = newSigKey()
-  var randaoSeed: Eth2Digest
-  if randomBytes(randaoSeed.data) != sizeof(randaoSeed.data):
+proc genSingleValidator(path: string): (ValidatorPubKey,
+                                        ValidatorPrivKey,
+                                        Eth2Digest) =
+  var v: PrivateValidatorData
+  v.privKey = newSigKey()
+  if randomBytes(v.randao.seed.data) != sizeof(v.randao.seed.data):
     raise newException(Exception, "Could not generate randao seed")
 
-  createDir(parentDir(path))
-  let pkPath = path & ".privkey"
-  let randaoPath = path & ".randao"
-  writeFile(randaoPath, randaoSeed.data)
-  writeFile(pkPath, pk.getRaw())
-  echo "Generated privkey: ", pkPath
-  echo "Generated randao seed: ", randaoPath
+  writeFile(path, v)
+
+  return (v.privKey.pubKey(), v.privKey, v.randao.initialCommitment)
 
 proc printUsage() =
-  echo "Usage: validator_keygen <path>"
+  echo "Usage: validator_keygen <number-of-validators> <out-path>"
+
+# TODO: Make these more comprehensive and find them a new home
+type
+  Ether* = distinct int64
+  GWei* = distinct int64
+
+template eth*(x: SomeInteger): Ether = Ether(x)
+template gwei*(x: Ether): Gwei = Gwei(int(x) * 1000000000)
 
 proc main() =
-  if paramCount() != 1:
+  if paramCount() != 2:
     printUsage()
     return
 
-  let path = paramStr(1)
-  genKeys(path)
+  let totalValidators = parseInt paramStr(1)
+  if totalValidators < 64:
+    echo "The number of validators must be higher than ", EPOCH_LENGTH, " (EPOCH_LENGTH)"
+    echo "There must be at least one validator assigned per slot."
+    quit 1
 
+  let outPath = paramStr(2)
+
+  var startupData: ChainStartupData
+
+  for i in 1 .. totalValidators:
+    let (pubKey, privKey, randaoCommitment) =
+
+      genSingleValidator(outPath / &"validator-{i:02}.json")
+
+    let withdrawalCredentials = makeFakeHash(i)
+    let proofOfPossession = signMessage(privkey, hash_tree_root(
+      (pubKey, withdrawalCredentials, randaoCommitment)))
+
+    startupData.validatorDeposits.add Deposit(
+      deposit_data: DepositData(
+        value: MAX_DEPOSIT * GWEI_PER_ETH,
+        timestamp: now(),
+        deposit_parameters: DepositParameters(
+          pubkey: pubKey,
+          proof_of_possession: proofOfPossession,
+          withdrawal_credentials: withdrawalCredentials,
+          randao_commitment: randaoCommitment)))
+
+  startupData.genesisTime = now()
+
+  writeFile(outPath / "startup.json", startupData)
 
 when isMainModule:
   main()

beacon_chain/validator_pool.nim

@@ -25,6 +25,9 @@ type
 proc init*(T: type ValidatorPool): T =
   result.validators = initTable[ValidatorPubKey, AttachedValidator]()
 
+template count*(pool: ValidatorPool): int =
+  pool.validators.len
+
 proc addLocalValidator*(pool: var ValidatorPool,
                         idx: int,
                         pubKey: ValidatorPubKey,

tests/simulation/.gitignore

@@ -0,0 +1,2 @@
+*.json
+

tests/simulation/start.sh

@@ -0,0 +1,53 @@
+#!/bin/bash
+
+set -eu
+
+NUMBER_OF_VALIDATORS=99
+
+cd $(dirname "$0")
+SIMULATION_DIR=$PWD
+
+STARTUP_FILE="$SIMULATION_DIR/startup.json"
+SNAPSHOT_FILE="$SIMULATION_DIR/state_snapshot.json"
+
+cd $(git rev-parse --show-toplevel)
+ROOT_DIR=$PWD
+
+nim c beacon_chain/validator_keygen
+nim c beacon_chain/beacon_node
+
+if [ ! -f $STARTUP_FILE ]; then
+  beacon_chain/validator_keygen $NUMBER_OF_VALIDATORS "$SIMULATION_DIR"
+fi
+
+if [ ! -f $SNAPSHOT_FILE ]; then
+  beacon_chain/beacon_node createChain \
+    --chainStartupData:$STARTUP_FILE \
+    --out:$SNAPSHOT_FILE
+fi
+
+for i in $(seq 0 9); do
+  DATA_DIR=$SIMULATION_DIR/data-$i
+  BOOTSTRAP_NODES_FLAG=--bootstrapNodesFile:"$DATA_DIR/beacon_node.address"
+
+  if [[ "$i" == "0" ]]; then
+    BOOTSTRAP_NODES_FLAG=""
+  fi
+
+  beacon_chain/beacon_node \
+    --dataDir:"$DATA_DIR" \
+    --validator:"$SIMULATION_DIR/validator-${i}1.json" \
+    --validator:"$SIMULATION_DIR/validator-${i}2.json" \
+    --validator:"$SIMULATION_DIR/validator-${i}3.json" \
+    --validator:"$SIMULATION_DIR/validator-${i}4.json" \
+    --validator:"$SIMULATION_DIR/validator-${i}5.json" \
+    --validator:"$SIMULATION_DIR/validator-${i}6.json" \
+    --validator:"$SIMULATION_DIR/validator-${i}7.json" \
+    --validator:"$SIMULATION_DIR/validator-${i}8.json" \
+    --validator:"$SIMULATION_DIR/validator-${i}9.json" \
+    --tcpPort:5000$i \
+    --udpPort:5000$i \
+    --stateSnapshot:"$SNAPSHOT_FILE" \
+    $BOOTSTRAP_NODES_FLAG &
+done
+

tests/testutil.nim

@@ -17,7 +17,7 @@ func makeValidatorPrivKey(i: int): ValidatorPrivKey =
   var i = i + 1 # 0 does not work, as private key...
   copyMem(result.x[0].addr, i.addr, min(sizeof(result.x), sizeof(i)))
 
-func makeFakeHash(i: int): Eth2Digest =
+func makeFakeHash*(i: int): Eth2Digest =
   copyMem(result.data[0].addr, i.unsafeAddr, min(sizeof(result.data), sizeof(i)))
 
 func hackPrivKey(v: ValidatorRecord): ValidatorPrivKey =