Add support for spawning peers, and monitoring the processes

default.nix

@@ -3,9 +3,10 @@
   pkgs,
   mixRelease,
   elixir,
+  fetchMixDeps,
 }: let
   pname = "frajtano";
-  pkg = mixRelease {
+  pkg = mixRelease rec {
     inherit pname;
     version = "0.0.1";
 
@@ -16,6 +17,18 @@
       filter = path: _type: baseNameOf path != "flake.nix" && baseNameOf path != "flake.lock";
     };
 
+    # Adapted from https://blog.eigenvalue.net/nix-rerunning-fixed-output-derivations/
+    # deps hash should change any time ./mix.lock changes, and not otherwise
+    mixFodDeps = let
+      deps = fetchMixDeps {
+        pname = "mix-deps-${pname}";
+        inherit version src;
+        sha256 = "sha256-4g5lUlr5+l+mNVp0InZkx6X31g2cckI8NNQp37QgBis=";
+      };
+      hash = builtins.substring 11 32 "${./mix.lock}";
+    in
+      deps.overrideAttrs (attrs: {name = "${deps.name}-${hash}";});
+
     ELIXIR_MAKE_CACHE_DIR = "/tmp/.elixir-make-cache";
     meta.mainProgram = pname;
   };
@@ -25,14 +38,24 @@
     file="$FRAJTANO_DIR/cookie"
     (umask 077; [ -f "$file" ] || ${pkgs.coreutils}/bin/head -c 128 /dev/urandom | ${pkgs.coreutils}/bin/base64 -w0 > "$file")
     export RELEASE_COOKIE=$(${pkgs.coreutils}/bin/cat "$file")
-    export RELEASE_NODE="frajtano-$(${pkgs.coreutils}/bin/whoami)@$(${pkgs.coreutils}/bin/cat /etc/hostname)"
+    [ -n $RELEASE_NODE ] || export RELEASE_NODE="frajtano-$(${pkgs.coreutils}/bin/whoami)@$(${pkgs.coreutils}/bin/cat /etc/hostname)"
     run() {
       exec ${lib.getExe pkg} "$@"
     }
 
+    list() {
+      for i in "$@"; do
+        echo "\"$i\", "
+      done
+    }
+
     case "''${1:-}" in
       assimilate)
-        run rpc ":ok = \"$(echo -n "$2" | ${pkgs.coreutils}/bin/base64)\" |> Base.decode64!() |> Frajtano.Agent.add_peer()"
+        run rpc ":ok = \"$(echo -n "$2" | ${pkgs.coreutils}/bin/base64)\" |> Base.decode64!() |> Frajtano.Agent.assimilate()"
+      ;;
+      spawn)
+        shift
+        run rpc ":ok = Frajtano.Agent.spawn_peer({\"/usr/bin/env\", [$(list "$@")]})"
       ;;
       socket)
         echo $FRAJTANO_DIR/agent.sock
@@ -42,4 +65,9 @@
       ;;
     esac
   '';
-in pkgs.symlinkJoin { name = pname; paths = [ script pkg ]; meta.mainProgram = pname; }
+in
+  pkgs.symlinkJoin {
+    name = pname;
+    paths = [script pkg];
+    meta.mainProgram = pname;
+  }