localnet: fix localnet by excluding self from persistent peers list (#6209)

Closes #6205

cmd/tendermint/commands/testnet.go

@@ -207,11 +207,11 @@ func testnetFiles(cmd *cobra.Command, args []string) error {
 
 	// Gather persistent peer addresses.
 	var (
-		persistentPeers string
+		persistentPeers = make([]string, 0)
 		err             error
 	)
 	if populatePersistentPeers {
-		persistentPeers, err = persistentPeersString(config)
+		persistentPeers, err = persistentPeersArray(config)
 		if err != nil {
 			_ = os.RemoveAll(outputDir)
 			return err
@@ -225,7 +225,14 @@ func testnetFiles(cmd *cobra.Command, args []string) error {
 		config.P2P.AddrBookStrict = false
 		config.P2P.AllowDuplicateIP = true
 		if populatePersistentPeers {
-			config.P2P.PersistentPeers = persistentPeers
+			persistentPeersWithoutSelf := make([]string, 0)
+			for j := 0; j < len(persistentPeers); j++ {
+				if j == i {
+					continue
+				}
+				persistentPeersWithoutSelf = append(persistentPeersWithoutSelf, persistentPeers[j])
+			}
+			config.P2P.PersistentPeers = strings.Join(persistentPeersWithoutSelf, ",")
 		}
 		config.Moniker = moniker(i)
 
@@ -256,18 +263,19 @@ func hostnameOrIP(i int) string {
 	return ip.String()
 }
 
-func persistentPeersString(config *cfg.Config) (string, error) {
-	persistentPeers := make([]string, nValidators+nNonValidators)
+// get an array of persistent peers
+func persistentPeersArray(config *cfg.Config) ([]string, error) {
+	peers := make([]string, nValidators+nNonValidators)
 	for i := 0; i < nValidators+nNonValidators; i++ {
 		nodeDir := filepath.Join(outputDir, fmt.Sprintf("%s%d", nodeDirPrefix, i))
 		config.SetRoot(nodeDir)
 		nodeKey, err := p2p.LoadNodeKey(config.NodeKeyFile())
 		if err != nil {
-			return "", err
+			return []string{}, err
 		}
-		persistentPeers[i] = p2p.IDAddressString(nodeKey.ID, fmt.Sprintf("%s:%d", hostnameOrIP(i), p2pPort))
+		peers[i] = p2p.IDAddressString(nodeKey.ID, fmt.Sprintf("%s:%d", hostnameOrIP(i), p2pPort))
 	}
-	return strings.Join(persistentPeers, ","), nil
+	return peers, nil
 }
 
 func moniker(i int) string {