implemented RPC as a service (#3)

commands/ingest/start.go

@@ -9,6 +9,7 @@ import (
 	"strconv"
 )
 
+// TODO: make this configurable via a config or parameter
 const connString = "postgres://postgres:[email protected]:15432/postgres?sslmode=disable"
 
 // StartCmd start ingest service

commands/rpc/rpc.go

@@ -15,4 +15,5 @@ var RpcCmd = &cobra.Command{
 }
 
 func init() {
+	RpcCmd.AddCommand(StartCmd)
 }

commands/rpc/start.go

@@ -0,0 +1,32 @@
+package rpc
+
+import (
+	"github.com/cometbft/rpc-companion/rpc"
+	"github.com/spf13/cobra"
+	"log"
+)
+
+// TODO: make this configurable via a config or parameter
+const connString = "postgres://postgres:[email protected]:15432/postgres?sslmode=disable"
+
+// StartCmd start RPC service
+var StartCmd = &cobra.Command{
+	Use:   "start",
+	Short: "Start RPC Service",
+	Long:  `The start command runs an instance of the RPC Service`,
+	Run: func(cmd *cobra.Command, args []string) {
+
+		//Instantiate a new Ingest Service
+		rpcSvc := rpc.NewService(connString)
+		err := rpcSvc.Serve()
+		if err != nil {
+			log.Fatalln("There's an error starting the RPC service:", err)
+		} else {
+			log.Println("Started RPC service...")
+		}
+
+	},
+}
+
+func init() {
+}

rpc/service.go

@@ -0,0 +1,98 @@
+package rpc
+
+import (
+	"encoding/json"
+	"fmt"
+	"github.com/cometbft/cometbft/rpc/jsonrpc/types"
+	"github.com/cometbft/rpc-companion/storage"
+	"log"
+	"net/http"
+	"strconv"
+)
+
+type Service struct {
+	Storage storage.IStorage
+}
+
+func NewService(connStr string) Service {
+
+	// Database
+	db := storage.PostgresStorage{
+		ConnectionString: connStr,
+	}
+
+	// Return an Ingest Service
+	return Service{
+		Storage: &db,
+	}
+}
+
+func (s *Service) Serve() error {
+
+	// Handler for the block endpoint
+	http.HandleFunc("/v1/block", s.handleBlock)
+
+	// Start the service
+	err := http.ListenAndServe(":8080", nil) // TODO: Make the port configurable
+	if err != nil {
+		return err
+	} else {
+		return nil
+	}
+}
+
+// Handles the '/v1/block' endpoint
+func (s *Service) handleBlock(writer http.ResponseWriter, request *http.Request) {
+	writer.Header().Set("Content-Type", "application/json")
+	conn, err := s.Storage.Connect()
+	defer conn.Close()
+	if err != nil {
+		log.Println("Error connecting to storage in handleBlock: ", err)
+		writer.WriteHeader(http.StatusInternalServerError)
+		writer.Write([]byte("Internal Server Error"))
+	} else {
+		if request.Method == "GET" {
+			h := request.URL.Query()["height"][0]
+			height, err := strconv.ParseInt(h, 10, 64)
+			if err != nil {
+				writer.WriteHeader(http.StatusBadRequest)
+				writer.Write([]byte("Bad Request. Invalid height"))
+			}
+			fmt.Printf("Block Request. Height: %v\n", height)
+			block, err := s.Storage.GetBlock(height)
+			if err != nil {
+				// TODO: If not records retrieved return a different status
+				log.Println("Error retrieving record from storage in handleBlock: ", err)
+				writer.WriteHeader(http.StatusInternalServerError)
+				writer.Write([]byte("Internal Server Error"))
+			}
+			// Return response
+			blockJSON, err := json.Marshal(block)
+			id := types.JSONRPCStringID("id")
+			if err != nil {
+				log.Println("Error marshalling block: ", err)
+				writer.WriteHeader(http.StatusInternalServerError)
+				writer.Write([]byte("Internal Server Error"))
+			} else {
+				RPCResponse := types.RPCResponse{
+					JSONRPC: "2.0",
+					ID:      id,
+					Result:  blockJSON,
+					Error:   nil,
+				}
+				resp, err := json.Marshal(RPCResponse)
+				if err != nil {
+					log.Println("Error marshalling RPCResponse: ", err)
+					writer.WriteHeader(http.StatusInternalServerError)
+					writer.Write([]byte("Internal Server Error"))
+				} else {
+					writer.WriteHeader(http.StatusOK)
+					writer.Write(resp)
+				}
+			}
+		} else {
+			writer.WriteHeader(http.StatusBadRequest)
+			writer.Write([]byte("Bad Request"))
+		}
+	}
+}