Dynamic validators set. (#5366)

* Initial commit.

* Fix argument to be optional.

* Adopt options.md.

beacon_chain/conf.nim

@@ -161,6 +161,10 @@ type
       desc: "A directory containing validator keystores"
       name: "validators-dir" .}: Option[InputDir]
 
+    validatorsSource* {.
+      desc: "Remote Web3Signer URL that will be used as a source of validators"
+      name: "validators-source"}: Option[string]
+
     secretsDirFlag* {.
       desc: "A directory containing validator keystore passwords"
       name: "secrets-dir" .}: Option[InputDir]
@@ -875,6 +879,10 @@ type
       desc: "A directory containing validator keystores"
       name: "validators-dir" .}: Option[InputDir]
 
+    validatorsSource* {.
+      desc: "Remote Web3Signer URL that will be used as a source of validators"
+      name: "validators-source"}: Option[string]
+
     secretsDirFlag* {.
       desc: "A directory containing validator keystore passwords"
       name: "secrets-dir" .}: Option[InputDir]

beacon_chain/nimbus_validator_client.nim

@@ -90,6 +90,9 @@ proc initValidators(vc: ValidatorClientRef): Future[bool] {.async.} =
   var duplicates: seq[ValidatorPubKey]
   for keystore in listLoadableKeystores(vc.config, vc.keystoreCache):
     vc.addValidator(keystore)
+  let dynamicKeystores = await queryValidatorsSource(vc.config)
+  for keystore in dynamicKeystores:
+    vc.addValidator(keystore)
   return true
 
 proc initClock(vc: ValidatorClientRef): Future[BeaconClock] {.async.} =

beacon_chain/spec/eth2_apis/rest_remote_signer_calls.nim

@@ -78,6 +78,11 @@ proc getKeys*(): RestResponse[Web3SignerKeysResponse] {.
      meth: MethodGet, accept: "application/json" .}
   ## https://consensys.github.io/web3signer/web3signer-eth2.html#tag/Public-Key
 
+proc getKeysPlain*(): RestPlainResponse {.
+     rest, endpoint: "/api/v1/eth2/publicKeys",
+     meth: MethodGet, accept: "application/json" .}
+  ## https://consensys.github.io/web3signer/web3signer-eth2.html#tag/Public-Key
+
 proc signDataPlain*(identifier: ValidatorPubKey,
                     body: Web3SignerRequest): RestPlainResponse {.
      rest, endpoint: "/api/v1/eth2/sign/{identifier}",

beacon_chain/spec/keystore.nim

@@ -130,7 +130,7 @@ type
     Local, Remote
 
   RemoteKeystoreFlag* {.pure.} = enum
-    IgnoreSSLVerification
+    IgnoreSSLVerification, DynamicKeystore
 
   HttpHostUri* = distinct Uri
 

beacon_chain/validators/beacon_validators.nim

@@ -117,8 +117,8 @@ proc getValidator*(validators: auto,
 proc addValidators*(node: BeaconNode) =
   info "Loading validators", validatorsDir = node.config.validatorsDir(),
                 keystore_cache_available = not(isNil(node.keystoreCache))
-  let
+  let epoch = node.currentSlot().epoch
-    epoch = node.currentSlot().epoch
+
   for keystore in listLoadableKeystores(node.config, node.keystoreCache):
     let
       data = withState(node.dag.headState):
@@ -132,7 +132,33 @@ proc addValidators*(node: BeaconNode) =
         keystore.pubkey, index, epoch)
       gasLimit = node.consensusManager[].getGasLimit(keystore.pubkey)
 
-      v = node.attachedValidators[].addValidator(keystore, feeRecipient, gasLimit)
+      v = node.attachedValidators[].addValidator(keystore, feeRecipient,
+                                                 gasLimit)
+    v.updateValidator(data)
+
+  let dynamicStores =
+    try:
+      waitFor(queryValidatorsSource(node.config))
+    except CatchableError as exc:
+      warn "Unexpected error happens while polling validator's source",
+           error = $exc.name, reason = $exc.msg
+      default(seq[KeystoreData])
+
+  for keystore in dynamicStores:
+    let
+      data =
+        withState(node.dag.headState):
+          getValidator(forkyState.data.validators.asSeq(), keystore.pubkey)
+      index =
+        if data.isSome():
+          Opt.some(data.get().index)
+        else:
+          Opt.none(ValidatorIndex)
+      feeRecipient =
+        node.consensusManager[].getFeeRecipient(keystore.pubkey, index, epoch)
+      gasLimit = node.consensusManager[].getGasLimit(keystore.pubkey)
+      v = node.attachedValidators[].addValidator(keystore, feeRecipient,
+                                                 gasLimit)
     v.updateValidator(data)
 
 proc getValidator*(node: BeaconNode, idx: ValidatorIndex): Opt[AttachedValidator] =

beacon_chain/validators/keystore_management.nim

@@ -627,6 +627,70 @@ proc existsKeystore(keystoreDir: string,
       return true
   false
 
+proc queryValidatorsSource*(config: AnyConf): Future[seq[KeystoreData]] {.
+     async.} =
+  var keystores: seq[KeystoreData]
+  if config.validatorsSource.isNone() or
+     len(config.validatorsSource.get()) == 0:
+    return keystores
+
+  let vsource = config.validatorsSource.get()
+  logScope:
+    validators_source = vsource
+
+  let
+    httpFlags: HttpClientFlags = {}
+    prestoFlags = {RestClientFlag.CommaSeparatedArray}
+    socketFlags = {SocketFlags.TcpNoDelay}
+    client =
+      block:
+        let res = RestClientRef.new(vsource, prestoFlags,
+                                    httpFlags, socketFlags = socketFlags)
+        if res.isErr():
+          # TODO keep trying in case of temporary network failure
+          warn "Unable to resolve validator's source distributed signer address"
+          return keystores
+        res.get()
+    keys =
+      try:
+        let response = await getKeysPlain(client)
+        if response.status != 200:
+          warn "Remote validator's source responded with error",
+               error = response.status
+          return keystores
+
+        let res = decodeBytes(Web3SignerKeysResponse, response.data,
+                              response.contentType)
+        if res.isErr():
+          warn "Unable to obtain validator's source response",
+               reason = res.error
+          return keystores
+
+        res.get()
+      except RestError as exc:
+        warn "Unable to poll validator's source", reason = $exc.msg
+        return keystores
+      except CancelledError as exc:
+        debug "The polling of validator's source was interrupted"
+        raise exc
+      except CatchableError as exc:
+        warn "Unexpected error occured while polling validator's source",
+             error = $exc.name, reason = $exc.msg
+        return keystores
+
+  for pubkey in keys:
+    keystores.add(KeystoreData(
+      kind: KeystoreKind.Remote,
+      handle: FileLockHandle(opened: false),
+      pubkey: pubkey,
+      remotes: @[RemoteSignerInfo(
+        url: HttpHostUri(parseUri(vsource)),
+        pubkey: pubkey)],
+      flags: {RemoteKeystoreFlag.DynamicKeystore},
+      remoteType: RemoteSignerType.Web3Signer))
+
+  keystores
+
 iterator listLoadableKeys*(validatorsDir, secretsDir: string,
                            keysMask: set[KeystoreKind]): CookedPubKey =
   try:
@@ -1244,8 +1308,8 @@ proc saveKeystore*(
 
 proc importKeystore*(pool: var ValidatorPool,
                      validatorsDir: string,
-                     keystore: RemoteKeystore): ImportResult[KeystoreData]
+                     keystore: RemoteKeystore): ImportResult[KeystoreData] {.
-                    {.raises: [].} =
+     raises: [].} =
   let
     publicKey = keystore.pubkey
     keyName = publicKey.fsName
@@ -1253,9 +1317,9 @@ proc importKeystore*(pool: var ValidatorPool,
 
   # We check `publicKey`.
   let cookedKey = publicKey.load().valueOr:
-        return err(
+    return err(
-          AddValidatorFailure.init(AddValidatorStatus.failed,
+      AddValidatorFailure.init(AddValidatorStatus.failed,
-                                   "Invalid validator's public key"))
+                               "Invalid validator's public key"))
 
   # We check `publicKey` in memory storage first.
   if publicKey in pool:

beacon_chain/validators/validator_pool.nim

@@ -146,12 +146,16 @@ proc addRemoteValidator(pool: var ValidatorPool, keystore: KeystoreData,
     activationEpoch: FAR_FUTURE_EPOCH,
   )
   pool.validators[v.pubkey] = v
-  notice "Remote validator attached",
+  if RemoteKeystoreFlag.DynamicKeystore in keystore.flags:
-    pubkey = v.pubkey,
+    notice "Dynamic remote validator attached", pubkey = v.pubkey,
-    validator = shortLog(v),
+           validator = shortLog(v), remote_signer = $keystore.remotes,
-    remote_signer = $keystore.remotes,
+           initial_fee_recipient = feeRecipient.toHex(),
-    initial_fee_recipient = feeRecipient.toHex(),
+           initial_gas_limit = gasLimit
-    initial_gas_limit = gasLimit
+  else:
+    notice "Remote validator attached", pubkey = v.pubkey,
+           validator = shortLog(v), remote_signer = $keystore.remotes,
+           initial_fee_recipient = feeRecipient.toHex(),
+           initial_gas_limit = gasLimit
 
   validators.set(pool.count().int64)
 

docs/the_nimbus_book/src/options.md

@@ -33,6 +33,7 @@ The following options are available:
      --network                 The Eth2 network to join [=mainnet].
  -d, --data-dir                The directory where nimbus will store all blockchain data.
      --validators-dir          A directory containing validator keystores.
+     --validators-source       Remote Web3Signer URL that will be used as a source of validators.
      --secrets-dir             A directory containing validator keystore passwords.
      --wallets-dir             A directory containing wallet files.
      --web3-url                One or more execution layer Engine API URLs.