4.0 KiB
libp2p Demos
Demo 1: DHT Peer & Content with Go and JS Nodes
Directory: content-dht-provide-find
What it demonstrates: A new DHT is created by the Go program dht-interop. In a separate terminal or machine, a Node.js program connects to this DHT. One connected, each verifies that it can find the other's content via the DHT.
First terminal:
cd content-dht-provide-find
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.
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.
Second terminal: run the command printed out by dht-interop, replacing 127.0.0.1 with the IP of the server where dht-interop is listening. Example:
Running the Node.js program:
cd content-dht-provide-find/js-dht-test
npm install # first time only
node js-dht-test/index.js /ip4/127.0.0.1/tcp/5555/ipfs/QmehVYruznbyDZuHBV4vEHESpDevMoAovET6aJ9oRuEzWa
Demo 2: PubSub
Directory: pubsub
What it demonstrates: Two Go peers, one JS peer, and one Rust peer are all created and run a chat server using a shared PubSub topic. Typing text in any peer sends it to all the other peers.
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)
First terminal: Create the bootstrapper node
cd pubsub
./pubsub-interop -b ../util/private_key.bin.bootstrapper.Wa
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.
Second terminal: Create a go peer to connect to bootstrapper and publish on the topic
cd pubsub
./pubsub-interop ../util/private_key.bin.peer.Sk
This peer, which is not in bootstrapper mode, creates a node, subscribes to the shared topic string, spawns the same go routine, and then loops forever requesting user input and publishing each line to the topic.
Third terminal: Create a JS peer to connect to bootstrap and publish on topic
cd pubsub/js
npm install # first time only
node index.js /ip4/127.0.0.1/tcp/5555/ipfs/QmehVYruznbyDZuHBV4vEHESpDevMoAovET6aJ9oRuEzWa
This JS peer will fire off a hello message every few seconds, which the other two subscribing nodes can see.
Fourth terminal: Createa a Rust peer to connect to the bootstrap node and then subscribe and publish on the topic:
cd pubsub/rust
cargo run
The Rust peer starts up, listens on port 6002, and then dials the boostrap peer. (TODO: rust-libp2p#471) It is now subscribed to the same topic as the other peers.
If you return to the second, third or fourth terminals and type a message, the bootstrapper and the other 2 peers will all print your message.
In short, you have a chat app on a private libp2p network using PubSub.
Debugging Notes
JS To see debug messages from the Node.js program, use the DEBUG environment variable:
DEBUG="libp2p:floodsub*,libp2p:switch*,mss:*" node index.js [args...]
Go To see debug messages in Go programs, do this at runtime:
IPFS_LOGGING=debug ./pubsub-interop [args...]
TODO: describe custom instrumenting the local go code
If you instrument your go code with custom fmt.Println's, then revert back like this:
cd $GOPATH
go get -u ./...
Other useful commands:
go get -u github.com/libp2p/go-libp2p-kad-dht # fetch just Kad DHT repo
Acknowledgements: @jhiesey for DHT (content & peer routing) JS+Go interop, @stebalien for PubSub