nixos/anbox: init module

Co-authored-by: Luke Adams <luke.adams@belljar.io>
Co-authored-by: Volth <volth@webmaster.ms>
Co-authored-by: Jörg Thalheim <Mic92@users.noreply.github.com>
Co-authored-by: Edward Tjörnhammar <ed@cflags.cc>
Co-authored-by: Gabriel Ebner <gebner@gebner.org>

nixos/modules/module-list.nix

@@ -873,6 +873,7 @@
   ./tasks/trackpoint.nix
   ./tasks/powertop.nix
   ./testing/service-runner.nix
+  ./virtualisation/anbox.nix
   ./virtualisation/container-config.nix
   ./virtualisation/containers.nix
   ./virtualisation/docker.nix

nixos/modules/virtualisation/anbox.nix

@@ -0,0 +1,144 @@
+{ config, lib, pkgs, ... }:
+
+with lib;
+
+let
+
+  cfg = config.virtualisation.anbox;
+  kernelPackages = config.boot.kernelPackages;
+  addrOpts = v: addr: pref: name: {
+    address = mkOption {
+      default = addr;
+      type = types.str;
+      description = ''
+        IPv${toString v} ${name} address.
+      '';
+    };
+
+    prefixLength = mkOption {
+      default = pref;
+      type = types.addCheck types.int (n: n >= 0 && n <= (if v == 4 then 32 else 128));
+      description = ''
+        Subnet mask of the ${name} address, specified as the number of
+        bits in the prefix (<literal>${if v == 4 then "24" else "64"}</literal>).
+      '';
+    };
+  };
+
+in
+
+{
+
+  options.virtualisation.anbox = {
+
+    enable = mkEnableOption "Anbox";
+
+    image = mkOption {
+      default = pkgs.anbox.image;
+      example = literalExample "pkgs.anbox.image";
+      type = types.package;
+      description = ''
+        Base android image for Anbox.
+      '';
+    };
+
+    extraInit = mkOption {
+      type = types.lines;
+      default = "";
+      description = ''
+        Extra shell commands to be run inside the container image during init.
+      '';
+    };
+
+    ipv4 = {
+      container = addrOpts 4 "192.168.250.2" 24 "Container";
+      gateway = addrOpts 4 "192.168.250.1" 24 "Host";
+
+      dns = mkOption {
+        default = "1.1.1.1";
+        type = types.string;
+        description = ''
+          Container DNS server.
+        '';
+      };
+    };
+  };
+
+  config = mkIf cfg.enable {
+
+    assertions = singleton {
+      assertion = versionAtLeast (getVersion config.boot.kernelPackages.kernel) "4.18";
+      message = "Anbox needs user namespace support to work properly";
+    };
+
+    environment.systemPackages = with pkgs; [ anbox ];
+
+    boot.kernelModules = [ "ashmem_linux" "binder_linux" ];
+    boot.extraModulePackages = [ kernelPackages.anbox ];
+
+    services.udev.extraRules = ''
+      KERNEL=="ashmem", NAME="%k", MODE="0666"
+      KERNEL=="binder*", NAME="%k", MODE="0666"
+    '';
+
+    virtualisation.lxc.enable = true;
+    networking.bridges.anbox0.interfaces = [];
+    networking.interfaces.anbox0.ipv4.addresses = [ cfg.ipv4.gateway ];
+
+    networking.nat = {
+      enable = true;
+      internalInterfaces = [ "anbox0" ];
+    };
+
+    systemd.services.anbox-container-manager = let
+      anboxloc = "/var/lib/anbox";
+    in {
+      description = "Anbox Container Management Daemon";
+
+      environment.XDG_RUNTIME_DIR="${anboxloc}";
+
+      wantedBy = [ "multi-user.target" ];
+      after = [ "systemd-udev-settle.service" ];
+      preStart = let
+        initsh = let
+          ip = cfg.ipv4.container.address;
+          gw = cfg.ipv4.gateway.address;
+          dns = cfg.ipv4.dns;
+        in
+        pkgs.writeText "nixos-init" (''
+          #!/system/bin/sh
+          setprop nixos.version ${config.system.nixos.version}
+
+          # we don't have radio
+          setprop ro.radio.noril yes
+          stop ril-daemon
+
+          # speed up boot
+          setprop debug.sf.nobootanimation 1
+        '' + cfg.extraInit);
+        initshloc = "${anboxloc}/rootfs-overlay/system/etc/init.goldfish.sh";
+      in ''
+        mkdir -p ${anboxloc}
+        mkdir -p $(dirname ${initshloc})
+        [ -f ${initshloc} ] && rm ${initshloc}
+        cp ${initsh} ${initshloc}
+        chown 100000:100000 ${initshloc}
+        chmod +x ${initshloc}
+      '';
+
+      serviceConfig = {
+        ExecStart = ''
+          ${pkgs.anbox}/bin/anbox container-manager \
+            --data-path=${anboxloc} \
+            --android-image=${cfg.image} \
+            --container-network-address=${cfg.ipv4.container.address} \
+            --container-network-gateway=${cfg.ipv4.gateway.address} \
+            --container-network-dns-servers=${cfg.ipv4.dns} \
+            --use-rootfs-overlay \
+            --privileged
+        '';
+      };
+    };
+  };
+
+}