add --bootstrapper and cleanup readme

README.md

@@ -13,7 +13,7 @@ make
 ./dht-interop -b ../util/private_key.bin.bootstrapper.Wa
 ```
 
-`-b` means bootstrap mode.  In this example, the go program is always the bootstrap node, so `-b` is always required.
+`-b` means bootstrap mode.  In this example, the go program is always the bootstrap node, so `-b` is always required. (***TODO***:  eliminate this superfluous option)
 
 Note that the node ID of `dht-interop` is always `Qm...6aJ9oRuEzWa` because it is being read in from `../util/private_key.bin.bootstrapper.Wa` (a private key marshalled to X.509 generated by the program `util/private-key-gen`).  This is to keep the peer id of the bootstrap server stable across invocations.
 
@@ -36,17 +36,19 @@ node js-dht-test/index.js /ip4/127.0.0.1/tcp/5555/ipfs/QmehVYruznbyDZuHBV4vEHESp
 
 **Quick test**:  `cd pubsub` and then run `./test/test.sh`.  Requires Terminator (eg, `sudo apt-get install terminator`).  The rest of this section describes how to test manually.
 
-(**TODO**:  eliminate centralized bootstrapper; any peer should be able to bootstrap from any other peer and peers should be able to start in any order)
+(**TODO**:  maybe eliminate centralized bootstrapper; any peer could then bootstrap from any other peer and peers could start in any order; downside is the code will be more complex in all peers)
 
 **First terminal**:  Create the bootstrapper node
 
 ```
 cd pubsub
-./pubsub-interop -b ../util/private_key.bin.bootstrapper.Wa
+./pubsub-interop ../util/private_key.bin.bootstrapper.Wa --bootstrapper
 ```
 
 The bootstrapper creates a new libp2p node, subscribes to the shared topic string, spawns a go routine to emit any publishes to that topic, and then waits forever.
 
+(Note that the node ID of `pubsub-interop` is going to be `Qm...6aJ9oRuEzWa`.  Node IDs in libp2p are just public keys, and the public key `Qm...6aJ9oRuEzWa` is derived from the private key file `../util/private_key.bin.bootstrapper.Wa`.  That file is just an X.509 keypair generated by the included program `util/private-key-gen`).  We use fixed public/private keypairs for each node in this example to keep things simple.)
+
 **Second terminal**:  Create a go peer to connect to bootstrapper and publish on the topic
 
 ```
@@ -65,7 +67,7 @@ node index.js /ip4/127.0.0.1/tcp/5555/ipfs/QmehVYruznbyDZuHBV4vEHESpDevMoAovET6a
 
 This JS peer will accept lines of text typed on stdin, and publish them on the PubSub topic.
 
-(**TODO**:  JS peer should listen for connections on 6001 from new peers)
+(Note that the JS peer generates a new identity (public/private keypair) each time, and prints its public key to stdout.  This is a deficiency in the demo; to be consistent with the Go code it should accept a private key on the CLI.)
 
 **Fourth terminal**:  Creates a Rust peer to connect to the bootstrap node and then subscribe and publish on the topic:
 

pubsub/pubsub-interop.go

@@ -27,7 +27,7 @@ var ho host.Host
 var TopicName string = "RDEpsjSPrAZF9JCK5REt3tao"
 
 func parseArgs() (bool, string) {
-	usage := fmt.Sprintf("Usage: %s [-b] [PRIVATE_KEY]\n\n-b is bootstrap mode (creates DHT)\nPRIVATE_KEY is the path to a private key like '../util/private_key.bin'\n", os.Args[0])
+	usage := fmt.Sprintf("Usage: %s PRIVATE_KEY [--bootstrapper]\n\nPRIVATE_KEY is the path to a private key like '../util/private_key.bin'\n--bootstrapper to run in bootstrap mode (creates a DHT and listens for peers)\n", os.Args[0])
 	var bBootstrap bool = false
 	var privKeyFilePath string
 	var args []string = os.Args[1:]
@@ -35,11 +35,10 @@ func parseArgs() (bool, string) {
 		fmt.Printf("Error: wrong number of arguments\n\n%s", usage)
 		os.Exit(1)
 	}
-	if args[0] == "-b" {
+	privKeyFilePath = args[0]
+	if (len(args) == 2) && (args[1] == "--bootstrapper") {
 		bBootstrap = true
-		args = args[1:]
 	}
-	privKeyFilePath = args[0]
 	return bBootstrap, privKeyFilePath
 }