working node discovery example using the iroh-gossip-discovery crate

.gitignore

@@ -2,3 +2,5 @@ target/
 *iroh-data
 */.sendme*
 /deploy-out
+.envrc
+.direnv

README.md

@@ -28,6 +28,10 @@ Use iroh through [extism]
 
 Experiment with [FROST] threshold signatures for iroh.
 
+### [gossip-node-discover](gossip-node-discover)
+
+Discover nodes via [iroh-gossip-discovery](https://crates.io/crates/iroh-gossip-discovery).
+
 ### [iroh-automerge](iroh-automerge)
 
 Iroh integration with [automerge]

flake.nix

@@ -0,0 +1,31 @@
+{
+  description = "A devShell example";
+
+  inputs = {
+    nixpkgs.url      = "github:NixOS/nixpkgs/nixos-unstable";
+    rust-overlay.url = "github:oxalica/rust-overlay";
+    flake-utils.url  = "github:numtide/flake-utils";
+  };
+
+  outputs = { self, nixpkgs, rust-overlay, flake-utils, ... }:
+    flake-utils.lib.eachDefaultSystem (system:
+      let
+        overlays = [ (import rust-overlay) ];
+        pkgs = import nixpkgs {
+          inherit system overlays;
+        };
+      in
+      with pkgs;
+      {
+        devShells.default = mkShell {
+          nativeBuildInputs = [
+            openssl
+            pkg-config
+            rust-bin.nightly.latest.default
+            rust-analyzer
+          ];
+          LIBCLANG_PATH = "${pkgs.libclang.lib}/lib";
+        };
+      }
+    );
+}

gossip-node-discover/README.md

@@ -0,0 +1,38 @@
+# gossip-node-discovery
+
+Discover nodes via [iroh-gossip-discovery](https://crates.io/crates/iroh-gossip-discovery).
+
+## node
+
+This binary will start an iroh endpoint and listen for NodeIds on the
+mDNS local discovery stream and also make an http request to a known
+server for it's NodeId. Once it gets one of these NodeId's it will
+subscribe to the [0u8; 32] topic Id and begin to send it's NodeId
+every 2 seconds. It also has a task that will listen for NodeId's that
+come on the gossip receiver stream and update a hashtable of known
+nodes.
+
+## whoami
+
+This is a simple http server that also subscribed to the gossip
+topic. `node` can hit this server if it can't find any seed NodeIds
+via mDNS.
+
+## Running the Demo
+
+If you are running locally and want to test via mDNS then just do:
+```
+cd node
+cargo run -- <name-of-node>
+```
+
+If you also want to test discovery using the `whoami` server do:
+```
+cd whoami
+cargo run
+```
+in another terminal
+```
+cd node
+cargo run -- <name-of-node>
+```