Update BlockChain to record NodeInfo (#95)

pkg/geth/node/node.go

@@ -0,0 +1,32 @@
+package node
+
+import (
+	"context"
+
+	"github.com/8thlight/vulcanizedb/pkg/core"
+	"github.com/ethereum/go-ethereum/p2p"
+	"github.com/ethereum/go-ethereum/rpc"
+)
+
+func Retrieve(client *rpc.Client) core.Node {
+	var info p2p.NodeInfo
+	node := core.Node{}
+	client.CallContext(context.Background(), &info, "admin_nodeInfo")
+	for protocolName, protocol := range info.Protocols {
+		if protocolName == "eth" {
+			protocolMap, _ := protocol.(map[string]interface{})
+			node.GenesisBlock = getAttribute(protocolMap, "genesis").(string)
+			node.NetworkId = getAttribute(protocolMap, "network").(float64)
+		}
+	}
+	return node
+}
+
+func getAttribute(protocolMap map[string]interface{}, protocol string) interface{} {
+	for key, val := range protocolMap {
+		if key == protocol {
+			return val
+		}
+	}
+	return nil
+}