bisq2: add webcam support (#440945)

pkgs/by-name/bi/bisq2/package.nix

@@ -1,8 +1,7 @@
 {
-  stdenvNoCC,
+  stdenv,
   lib,
   makeBinaryWrapper,
-  runtimeShell,
   fetchurl,
   makeDesktopItem,
   copyDesktopItems,
@@ -10,11 +9,18 @@
   jdk23,
   dpkg,
   writeShellScript,
-  bash,
   tor,
   zip,
   gnupg,
   coreutils,
+
+  # Used by the bundled webcam-app
+  libv4l,
+
+  # Used by the testing package bisq2-webcam-app
+  callPackage,
+  socat,
+  unzip,
 }:
 
 let
@@ -44,8 +50,18 @@ let
       hash = "sha256-PrRYZLT0xv82dUscOBgQGKNf6zwzWUDhriAffZbNpmI=";
     };
   };
+
+  binPath = lib.makeBinPath [
+    coreutils
+    tor
+  ];
+
+  libraryPath = lib.makeLibraryPath [
+    stdenv.cc.cc
+    libv4l
+  ];
 in
-stdenvNoCC.mkDerivation rec {
+stdenv.mkDerivation (finalAttrs: rec {
   inherit version;
 
   pname = "bisq2";
@@ -137,21 +153,11 @@ stdenvNoCC.mkDerivation rec {
 
     install -D -m 777 ${bisq-launcher ""} $out/bin/bisq2
     substituteAllInPlace $out/bin/bisq2
-    wrapProgram $out/bin/bisq2 --prefix PATH : ${
-      lib.makeBinPath [
-        coreutils
-        tor
-      ]
-    }
+    wrapProgram $out/bin/bisq2 --prefix PATH : ${binPath} --prefix LD_LIBRARY_PATH : ${libraryPath}
 
     install -D -m 777 ${bisq-launcher "-Dglass.gtk.uiScale=2.0"} $out/bin/bisq2-hidpi
     substituteAllInPlace $out/bin/bisq2-hidpi
-    wrapProgram $out/bin/bisq2-hidpi --prefix PATH : ${
-      lib.makeBinPath [
-        coreutils
-        tor
-      ]
-    }
+    wrapProgram $out/bin/bisq2-hidpi --prefix PATH : ${binPath} --prefix LD_LIBRARY_PATH : ${libraryPath}
 
     for n in 16 24 32 48 64 96 128 256; do
       size=$n"x"$n
@@ -162,6 +168,15 @@ stdenvNoCC.mkDerivation rec {
     runHook postInstall
   '';
 
+  # The bisq2.webcam-app package is for maintainers to test scanning QR codes.
+  passthru.webcam-app = callPackage ./webcam-app.nix {
+    inherit
+      jdk
+      libraryPath
+      ;
+    bisq2 = finalAttrs.finalPackage.out;
+  };
+
   meta = {
     description = "Decentralized bitcoin exchange network";
     homepage = "https://bisq.network";
@@ -176,4 +191,4 @@ stdenvNoCC.mkDerivation rec {
       "aarch64-linux"
     ];
   };
-}
+})

pkgs/by-name/bi/bisq2/webcam-app.nix

@@ -0,0 +1,56 @@
+# bisq2 contains a separate Java app which is used to scan Bitcoin Lightning QR codes.
+# bisq2 communicates with the webcam app via a local TCP connection using a simple one-way protocol.
+# Since the webcam app dynamically loads native code, this package is for maintainers to test QR code scanning without having to spend bitcoin to execute a trade.
+# This package is exposed as an attribute of the bisq2 package; bisq2.webcam-app.
+{
+  stdenv,
+  lib,
+  makeBinaryWrapper,
+  jdk,
+  writeShellScript,
+  unzip,
+  bisq2,
+  socat,
+  libraryPath,
+}:
+
+let
+  version = "1.0.0";
+
+  launcher = writeShellScript "bisq2-webcam-app-launcher" ''
+    ${socat}/bin/socat TCP-LISTEN:8000,keepalive,fork STDIO &
+    socat_pid=$!
+    LD_LIBRARY_PATH=${libraryPath} "${lib.getExe jdk}" -classpath @out@/lib/app/webcam-app-${version}-all.jar:${bisq2}/lib/app/* bisq.webcam.WebcamAppLauncher "$@"
+    kill $socat_pid
+  '';
+in
+stdenv.mkDerivation rec {
+  inherit version;
+
+  pname = "bisq2-webcam-app";
+  src = bisq2;
+  dontUnpack = true;
+
+  nativeBuildInputs = [
+    makeBinaryWrapper
+    unzip
+  ];
+
+  buildPhase = ''
+    # Extract the webcam app from Bisq2.
+
+    unzip ${bisq2}/lib/app/desktop.jar 'webcam-app/*'
+    unzip webcam-app/webcam-app-1.0.0.zip
+  '';
+
+  installPhase = ''
+    runHook preInstall
+
+    mkdir -p $out/lib/app $out/bin
+    cp webcam-app-${version}-all.jar $out/lib/app/
+    install -D -m 777 ${launcher} $out/bin/bisq2-webcam-app
+    substituteAllInPlace $out/bin/bisq2-webcam-app
+
+    runHook postInstall
+  '';
+}