Add reverse peer assignment

core/Blockchain.go

@@ -1,6 +1,7 @@
 package core
 
 import (
+	"bytes"
 	"encoding/json"
 	"log"
 	"net/http"
@@ -10,6 +11,7 @@ import (
 
 // Blockchain struct
 type Blockchain struct {
+	Hostname            string
 	Blocks              []Block
 	PendingTransactions []Transaction
 	Peers               []string
@@ -38,10 +40,10 @@ func (bc *Blockchain) MineBlock() Block {
 }
 
 // NewBlockchain creates a new Blockchain
-func NewBlockchain() Blockchain {
+func NewBlockchain(hostname string) Blockchain {
 	log.Print("Creating Blockchain...")
 
-	blockchain := Blockchain{Blocks: make([]Block, 0), PendingTransactions: make([]Transaction, 0), Peers: make([]string, 0)}
+	blockchain := Blockchain{Hostname: hostname, Blocks: make([]Block, 0), PendingTransactions: make([]Transaction, 0), Peers: make([]string, 0)}
 
 	// Mine Genesis Block
 	blockchain.MineBlock()
@@ -77,6 +79,12 @@ func (bc *Blockchain) AddPeer(peer string) (resp *http.Response, err error) {
 	// Add Peer, if it is not already in the list
 	if !contains(bc.Peers, peer) {
 		bc.Peers = append(bc.Peers, peer)
+
+		var body []string
+		data, _ := json.Marshal(append(body, bc.Hostname))
+
+		log.Println("request http://" + peer + "/add_peers")
+		http.Post("http://"+peer+"/add_peers", "application/json", bytes.NewBuffer(data))
 	}
 	return resp, nil
 }

server/webserver.go

@@ -4,7 +4,9 @@ import (
 	"encoding/gob"
 	"encoding/json"
 	"log"
+	"net"
 	"net/http"
+	"os"
 
 	"github.com/garritfra/blockchain-project/core"
 )
@@ -17,7 +19,7 @@ func ServeHTTP(port string) {
 	gob.Register(core.Transaction{})
 	gob.Register(core.Blockchain{})
 
-	blockchain = core.NewBlockchain()
+	blockchain = core.NewBlockchain(getHostAddress() + port)
 
 	registerRouteHandlers()
 
@@ -27,6 +29,23 @@ func ServeHTTP(port string) {
 	}
 }
 
+func getHostAddress() string {
+	addrs, err := net.InterfaceAddrs()
+	if err != nil {
+		os.Stderr.WriteString("Oops: " + err.Error() + "\n")
+		os.Exit(1)
+	}
+
+	for _, a := range addrs {
+		if ipnet, ok := a.(*net.IPNet); ok && !ipnet.IP.IsLoopback() {
+			if ipnet.IP.To4() != nil {
+				return ipnet.IP.String()
+			}
+		}
+	}
+	return ""
+}
+
 func registerRouteHandlers() {
 	http.HandleFunc("/", handleListBlocks)
 	http.HandleFunc("/mine_block", handleMineBlock)