implement "net_nodeInfo" rpc

fixes #569

nimbus/rpc/common.nim

@@ -8,10 +8,22 @@
 # those terms.
 
 import
-  strutils, tables,
+  std/[strutils, tables],
   nimcrypto, eth/common as eth_common, stint, json_rpc/server,
-  eth/p2p,
-  ../config, hexstrings
+  eth/p2p, eth/p2p/enode,
+  ../config, ./hexstrings
+
+type
+  NodePorts = object
+    discovery: string
+    listener : string
+
+  NodeInfo = object
+    id    : string # UInt256 hex
+    name  : string
+    enode : string # Enode string
+    ip    : string # address string
+    ports : NodePorts
 
 proc setupCommonRPC*(node: EthereumNode, server: RpcServer) =
   server.rpc("web3_clientVersion") do() -> string:
@@ -33,3 +45,16 @@ proc setupCommonRPC*(node: EthereumNode, server: RpcServer) =
   server.rpc("net_peerCount") do() -> HexQuantityStr:
     let peerCount = uint node.peerPool.connectedNodes.len
     result = encodeQuantity(peerCount)
+
+  server.rpc("net_nodeInfo") do() -> NodeInfo:
+    let enode = toEnode(node)
+    result = NodeInfo(
+      id: node.discovery.thisNode.id.toHex,
+      name: NimbusIdent,
+      enode: $enode,
+      ip: $enode.address.ip,
+      ports: NodePorts(
+        discovery: $enode.address.udpPort,
+        listener: $enode.address.tcpPort
+      )
+    )