[RPC] Expose node metadata

internal/hmyapi/README.md

@@ -10,6 +10,7 @@
 * [x] hmy_protocolVersion - check protocol version
 * [ ] net_version - get network id
 * [ ] net_peerCount - peer count
+* [x] hmy_getNodeMetadata - get node's version, bls key
 
 ### BlockChain info related
 * [ ] hmy_gasPrice - return min-gas-price

internal/hmyapi/harmony.go

@@ -6,6 +6,7 @@ import (
 
 	"github.com/ethereum/go-ethereum/common/hexutil"
 	"github.com/harmony-one/harmony/api/proto"
+	nodeconfig "github.com/harmony-one/harmony/internal/configs/node"
 )
 
 // PublicHarmonyAPI provides an API to access Harmony related information.
@@ -41,3 +42,18 @@ func (s *PublicHarmonyAPI) GasPrice(ctx context.Context) (*hexutil.Big, error) {
 	// TODO(ricl): add SuggestPrice API
 	return (*hexutil.Big)(big.NewInt(1)), nil
 }
+
+type NodeMetadata struct {
+	BLSPublicKey string `json:"blskey"`
+	Version      string `json:"version"`
+	NetworkType  string `json:"network"`
+}
+
+func (s *PublicHarmonyAPI) GetNodeMetadata() NodeMetadata {
+	cfg := nodeconfig.GetDefaultConfig()
+	return NodeMetadata{
+		cfg.ConsensusPubKey.SerializeToHexStr(),
+		nodeconfig.GetVersion(),
+		string(cfg.GetNetworkType()),
+	}
+}