Add cli option for providing bootstrap and static peers by ENR (#1634)

* Add cli option for providing bootstrap and static peers by ENR

* Minor bootstrap and static peers loading clean-up

nimbus/config.nim

@@ -24,7 +24,7 @@ import
     confutils/std/net
   ],
   stew/shims/net as stewNet,
-  eth/[common, net/nat, p2p/bootnodes, p2p/enode],
+  eth/[common, net/nat, p2p/bootnodes, p2p/enode, p2p/discoveryv5/enr],
   "."/[db/select_backend,
     constants, vm_compile_info, version
   ],
@@ -278,6 +278,12 @@ type
       defaultValue: ""
       name: "bootstrap-file" }: InputFile
 
+    bootstrapEnrs {.
+      desc: "ENR URI of node to bootstrap discovery from. Argument may be repeated"
+      defaultValue: @[]
+      defaultValueDesc: ""
+      name: "bootstrap-enr" }: seq[enr.Record]
+
     staticPeers {.
       desc: "Connect to one or more trusted peers(as enode URL)"
       defaultValue: @[]
@@ -291,6 +297,12 @@ type
       defaultValue: ""
       name: "static-peers-file" }: InputFile
 
+    staticPeersEnrs {.
+      desc: "ENR URI of node to connect to as trusted peer. Argument may be repeated"
+      defaultValue: @[]
+      defaultValueDesc: ""
+      name: "static-peer-enr" }: seq[enr.Record]
+
     reconnectMaxRetry* {.
       desc: "Specifies max number of retries if static peers disconnected/not connected. " &
             "0 = infinite."
@@ -541,6 +553,13 @@ proc parseCmdArg(T: type EthAddress, p: string): T
 proc completeCmdArg(T: type EthAddress, val: string): seq[string] =
   return @[]
 
+proc parseCmdArg*(T: type enr.Record, p: string): T {.raises: [ValueError].} =
+  if not fromURI(result, p):
+    raise newException(ValueError, "Invalid ENR")
+
+proc completeCmdArg*(T: type enr.Record, val: string): seq[string] =
+  return @[]
+
 proc processList(v: string, o: var seq[string])
     =
   ## Process comma-separated list of strings.
@@ -560,11 +579,10 @@ proc parseCmdArg(T: type NetworkParams, p: string): T
 proc completeCmdArg(T: type NetworkParams, val: string): seq[string] =
   return @[]
 
-proc setBootnodes(output: var seq[ENode], nodeUris: openArray[string])
-    {.gcsafe, raises: [CatchableError].} =
+proc setBootnodes(output: var seq[ENode], nodeUris: openArray[string]) =
   output = newSeqOfCap[ENode](nodeUris.len)
   for item in nodeUris:
-    output.add(ENode.fromString(item).tryGet())
+    output.add(ENode.fromString(item).expect("valid hardcoded ENode"))
 
 iterator repeatingList(listOfList: openArray[string]): string
     =
@@ -679,39 +697,83 @@ proc getRpcFlags*(conf: NimbusConf): set[RpcFlag] =
 proc getWsFlags*(conf: NimbusConf): set[RpcFlag] =
   getRpcFlags(conf.wsApi)
 
-proc getBootNodes*(conf: NimbusConf): seq[ENode]
-    {.gcsafe, raises: [CatchableError].} =
+proc fromEnr*(T: type ENode, r: enr.Record): ENodeResult[ENode] =
+  let
+    # TODO: there must always be a public key, else no signature verification
+    # could have been done and no Record would exist here.
+    # TypedRecord should be reworked not to have public key as an option.
+    pk = r.get(PublicKey).get()
+    tr = r.toTypedRecord().expect("id in valid record")
+
+  if tr.ip.isNone():
+    return err(IncorrectIP)
+  if tr.udp.isNone():
+    return err(IncorrectDiscPort)
+  if tr.tcp.isNone():
+    return err(IncorrectPort)
+
+  ok(ENode(
+    pubkey: pk,
+    address: Address(
+      ip: ipv4(tr.ip.get()),
+      udpPort: Port(tr.udp.get()),
+      tcpPort: Port(tr.tcp.get())
+    )
+  ))
+
+proc getBootNodes*(conf: NimbusConf): seq[ENode] =
+  var bootstrapNodes: seq[ENode]
   # Ignore standard bootnodes if customNetwork is loaded
   if conf.customNetwork.isNone:
     case conf.networkId
     of MainNet:
-      result.setBootnodes(MainnetBootnodes)
+      bootstrapNodes.setBootnodes(MainnetBootnodes)
     of RopstenNet:
-      result.setBootnodes(RopstenBootnodes)
+      bootstrapNodes.setBootnodes(RopstenBootnodes)
     of RinkebyNet:
-      result.setBootnodes(RinkebyBootnodes)
+      bootstrapNodes.setBootnodes(RinkebyBootnodes)
     of GoerliNet:
-      result.setBootnodes(GoerliBootnodes)
+      bootstrapNodes.setBootnodes(GoerliBootnodes)
     of KovanNet:
-      result.setBootnodes(KovanBootnodes)
+      bootstrapNodes.setBootnodes(KovanBootnodes)
     of SepoliaNet:
-      result.setBootnodes(SepoliaBootnodes)
+      bootstrapNodes.setBootnodes(SepoliaBootnodes)
     else:
       # custom network id
       discard
 
-  # always allow custom boostrap nodes
-  # if it is set by user
+  # always allow bootstrap nodes provided by the user
   if conf.bootstrapNodes.len > 0:
-    result.append(conf.bootstrapNodes)
+    bootstrapNodes.append(conf.bootstrapNodes)
 
   # bootstrap nodes loaded from file might append or
   # override built-in bootnodes
-  loadBootstrapFile(string conf.bootstrapFile, result)
+  loadBootstrapFile(string conf.bootstrapFile, bootstrapNodes)
+
+  # Bootstrap nodes provided as ENRs
+  for enr in conf.bootstrapEnrs:
+    let enode = Enode.fromEnr(enr).valueOr:
+      fatal "Invalid bootstrap ENR provided", error
+      quit 1
+
+    bootstrapNodes.add(enode)
+
+  bootstrapNodes
 
 proc getStaticPeers*(conf: NimbusConf): seq[ENode] =
-  result.append(conf.staticPeers)
-  loadStaticPeersFile(string conf.staticPeersFile, result)
+  var staticPeers: seq[ENode]
+  staticPeers.append(conf.staticPeers)
+  loadStaticPeersFile(string conf.staticPeersFile, staticPeers)
+
+  # Static peers provided as ENRs
+  for enr in conf.staticPeersEnrs:
+    let enode = Enode.fromEnr(enr).valueOr:
+      fatal "Invalid static peer ENR provided", error
+      quit 1
+
+    staticPeers.add(enode)
+
+  staticPeers
 
 proc getAllowedOrigins*(conf: NimbusConf): seq[Uri] =
   for item in repeatingList(conf.allowedOrigins):