tendermint testnet: Allow for better hostname control

CHANGELOG_PENDING.md

@@ -34,8 +34,11 @@
 - [p2p] [\#3463](https://github.com/tendermint/tendermint/pull/3463) Do not log "Can't add peer's address to addrbook" error for a private peer
 - [p2p] [\#3552](https://github.com/tendermint/tendermint/pull/3552) Add PeerBehaviour Interface (@brapse)
 - [rpc] [\#3534](https://github.com/tendermint/tendermint/pull/3534) Add support for batched requests/responses in JSON RPC
+- [cli] [\#3661](https://github.com/tendermint/tendermint/pull/3661) Add
+  `--hostname-suffix`, `--hostname` and `--random-monikers` options to `testnet`
+  cmd for greater peer address/identity generation flexibility.
 - [cli] \#3585 Add option to not clear address book with unsafe reset (@climber73)
-- [cli] [\#3160](https://github.com/tendermint/tendermint/issues/3160) Add `-config=<path-to-config>` option to `testnet` cmd (@gregdhill)
+- [cli] [\#3160](https://github.com/tendermint/tendermint/issues/3160) Add `--config=<path-to-config>` option to `testnet` cmd (@gregdhill)
 - [cs/replay] \#3460 check appHash for each block
 - [rpc] \#3362 `/dial_seeds` & `/dial_peers` return errors if addresses are incorrect (except when IP lookup fails)
 - [node] \#3362 returns an error if `persistent_peers` list is invalid (except when IP lookup fails)

cmd/tendermint/commands/testnet.go

@@ -27,8 +27,11 @@ var (
 
 	populatePersistentPeers bool
 	hostnamePrefix          string
+	hostnameSuffix          string
 	startingIPAddress       string
+	hostnames               []string
 	p2pPort                 int
+	randomMonikers          bool
 )
 
 const (
@@ -50,11 +53,17 @@ func init() {
 	TestnetFilesCmd.Flags().BoolVar(&populatePersistentPeers, "populate-persistent-peers", true,
 		"Update config of each node with the list of persistent peers build using either hostname-prefix or starting-ip-address")
 	TestnetFilesCmd.Flags().StringVar(&hostnamePrefix, "hostname-prefix", "node",
-		"Hostname prefix (node results in persistent peers list ID0@node0:26656, ID1@node1:26656, ...)")
+		"Hostname prefix (\"node\" results in persistent peers list ID0@node0:26656, ID1@node1:26656, ...)")
+	TestnetFilesCmd.Flags().StringVar(&hostnameSuffix, "hostname-suffix", "",
+		"Hostname suffix (\".xyz.com\" results in persistent peers list ID0@node0.xyz.com:26656, ID1@node1.xyz.com:26656, ...)")
 	TestnetFilesCmd.Flags().StringVar(&startingIPAddress, "starting-ip-address", "",
-		"Starting IP address (192.168.0.1 results in persistent peers list ID0@192.168.0.1:26656, ID1@192.168.0.2:26656, ...)")
+		"Starting IP address (\"192.168.0.1\" results in persistent peers list ID0@192.168.0.1:26656, ID1@192.168.0.2:26656, ...)")
+	TestnetFilesCmd.Flags().StringArrayVar(&hostnames, "hostname", []string{},
+		"Manually override all hostnames of validators and non-validators (use --hostname multiple times for multiple hosts)")
 	TestnetFilesCmd.Flags().IntVar(&p2pPort, "p2p-port", 26656,
 		"P2P Port")
+	TestnetFilesCmd.Flags().BoolVar(&randomMonikers, "random-monikers", false,
+		"Randomize the moniker for each generated node")
 }
 
 // TestnetFilesCmd allows initialisation of files for a Tendermint testnet.
@@ -76,6 +85,13 @@ Example:
 }
 
 func testnetFiles(cmd *cobra.Command, args []string) error {
+	if len(hostnames) > 0 && len(hostnames) != (nValidators+nNonValidators) {
+		return fmt.Errorf(
+			"testnet needs precisely %d hostnames (number of validators plus non-validators) if --hostname parameter is used",
+			nValidators+nNonValidators,
+		)
+	}
+
 	config := cfg.DefaultConfig()
 
 	// overwrite default config if set and valid
@@ -181,6 +197,7 @@ func testnetFiles(cmd *cobra.Command, args []string) error {
 		if populatePersistentPeers {
 			config.P2P.PersistentPeers = persistentPeers
 		}
+		config.Moniker = moniker(i)
 
 		cfg.WriteConfigFile(filepath.Join(nodeDir, "config", "config.toml"), config)
 	}
@@ -190,21 +207,23 @@ func testnetFiles(cmd *cobra.Command, args []string) error {
 }
 
 func hostnameOrIP(i int) string {
-	if startingIPAddress != "" {
-		ip := net.ParseIP(startingIPAddress)
-		ip = ip.To4()
-		if ip == nil {
-			fmt.Printf("%v: non ipv4 address\n", startingIPAddress)
-			os.Exit(1)
-		}
-
-		for j := 0; j < i; j++ {
-			ip[3]++
-		}
-		return ip.String()
+	if len(hostnames) > 0 && i < len(hostnames) {
+		return hostnames[i]
+	}
+	if startingIPAddress == "" {
+		return fmt.Sprintf("%s%d%s", hostnamePrefix, i, hostnameSuffix)
+	}
+	ip := net.ParseIP(startingIPAddress)
+	ip = ip.To4()
+	if ip == nil {
+		fmt.Printf("%v: non ipv4 address\n", startingIPAddress)
+		os.Exit(1)
 	}
 
-	return fmt.Sprintf("%s%d", hostnamePrefix, i)
+	for j := 0; j < i; j++ {
+		ip[3]++
+	}
+	return ip.String()
 }
 
 func persistentPeersString(config *cfg.Config) (string, error) {
@@ -220,3 +239,20 @@ func persistentPeersString(config *cfg.Config) (string, error) {
 	}
 	return strings.Join(persistentPeers, ","), nil
 }
+
+func moniker(i int) string {
+	if randomMonikers {
+		return randomMoniker()
+	}
+	if len(hostnames) > 0 && i < len(hostnames) {
+		return hostnames[i]
+	}
+	if startingIPAddress == "" {
+		return fmt.Sprintf("%s%d%s", hostnamePrefix, i, hostnameSuffix)
+	}
+	return randomMoniker()
+}
+
+func randomMoniker() string {
+	return cmn.HexBytes(cmn.RandBytes(8)).String()
+}