feat: add drone (ArduPilot SITL + Gazebo) simulation

.gitignore

@@ -10,6 +10,9 @@
 # pixi
 .pixi/
 
+# native builds
+.native/
+
 # Python
 .mypy_cache
 __pycache__
@@ -22,6 +25,13 @@ gazebo/install
 gazebo/build
 gazebo/log
 
+# drone stuff
+gazebo/eeprom.bin
+gazebo/logs/
+gazebo/terrain/
+gazebo/dumpcore.sh_arducopter.*.out
+gazebo/dumpstack.sh_arducopter.*.out
+
 # sim create tests
 cli/gazebo/create/tests
 

cli/cli.py

@@ -10,7 +10,7 @@
 from .output import die, info
 from .paths import GAZEBO_WORKSPACE_DIR
 
-_GAZEBO_SUBCOMMANDS = frozenset({"clean", "create", "update", "auth"})
+_GAZEBO_SUBCOMMANDS = frozenset({"clean", "create", "update", "auth", "setup-drone"})
 
 
 def _build_gazebo_parser(subparsers: argparse._SubParsersAction) -> tuple:
@@ -60,6 +60,11 @@ def _build_gazebo_parser(subparsers: argparse._SubParsersAction) -> tuple:
 
     gsubs.add_parser("auth", help="Configure dashboard API key for OnShape access")
 
+    gsubs.add_parser(
+        "setup-drone",
+        help="Build ArduPilot SITL + ardupilot_gazebo plugin (one-time, for 'sim gazebo drone')",
+    )
+
     return gazebo, gsubs, create_p
 
 
@@ -204,6 +209,11 @@ def _dispatch_gazebo(args, create_p) -> None:
     elif args.command == "auth":
         cmd_auth()
 
+    elif args.command == "setup-drone":
+        from .gazebo.ardupilot import setup as ardupilot_setup
+
+        ardupilot_setup()
+
 
 if __name__ == "__main__":
     main()

cli/gazebo/ardupilot.py

@@ -0,0 +1,238 @@
+"""ArduPilot SITL + ardupilot_gazebo plugin setup for the drone simulation.
+
+Builds both from source into `.native/` (gitignored), separate from the
+Docker image build - run once via `sim gazebo setup-drone`.
+"""
+
+from __future__ import annotations
+
+import getpass
+import os
+import subprocess
+from pathlib import Path
+
+from ..output import die, info, run_step
+from ..paths import ARDUPILOT_DIR, ARDUPILOT_GAZEBO_DIR
+
+ARDUPILOT_REPO = "https://github.com/ArduPilot/ardupilot.git"
+ARDUPILOT_REF = "Copter-4.3.7"
+
+# Copter-4.3.7 pins modules/waf at a 2019-era commit that still uses the
+# `imp` module, removed in Python 3.12 (Ubuntu 24.04's default python3).
+# waf is only a host-side build tool - it isn't part of the firmware - so
+# it's safe to move just this submodule forward to the commit later
+# ArduPilot releases (e.g. Copter-4.6.2) use, which supports Python 3.12.
+ARDUPILOT_WAF_COMMIT = "35eadbb64e2052099a853b571e507c33032b392c"
+
+ARDUPILOT_GAZEBO_REPO = "https://github.com/ArduPilot/ardupilot_gazebo.git"
+
+ARDUCOPTER_BIN = ARDUPILOT_DIR / "build" / "sitl" / "bin" / "arducopter"
+ARDUPILOT_GAZEBO_BUILD_DIR = ARDUPILOT_GAZEBO_DIR / "build"
+ARDUPILOT_GAZEBO_PLUGIN = ARDUPILOT_GAZEBO_BUILD_DIR / "libArduPilotPlugin.so"
+
+
+def is_installed() -> bool:
+    """Whether ArduCopter SITL and the ardupilot_gazebo plugin are already built"""
+    return ARDUCOPTER_BIN.is_file() and ARDUPILOT_GAZEBO_PLUGIN.is_file()
+
+
+def _run(command: list[str], *, cwd: Path, env: dict[str, str] | None = None) -> None:
+    result = subprocess.run(command, cwd=cwd, env=env, check=False)  # noqa: S603
+    if result.returncode != 0:
+        raise subprocess.CalledProcessError(result.returncode, command)
+
+
+def _clone_ardupilot() -> None:
+    if ARDUPILOT_DIR.is_dir():
+        info(f"ArduPilot already cloned at {ARDUPILOT_DIR}")
+        return
+    ARDUPILOT_DIR.parent.mkdir(parents=True, exist_ok=True)
+    _run(
+        [
+            "git",
+            "clone",
+            "--recurse-submodules",
+            "--branch",
+            ARDUPILOT_REF,
+            ARDUPILOT_REPO,
+            str(ARDUPILOT_DIR),
+        ],
+        cwd=ARDUPILOT_DIR.parent,
+    )
+
+
+_BUILD_APT_PACKAGES = [
+    "build-essential",
+    "ccache",
+    "g++",
+    "gawk",
+    "git",
+    "make",
+    "wget",
+    "python3-dev",
+    "python3-pip",
+    "libtool-bin",
+    "rsync",
+]
+
+# empy is pinned: newer empy (4.x) changed its API and breaks ArduPilot's
+# waf build scripts, which still use the old empy 3.3.4 templating API.
+_BUILD_PIP_PACKAGES = [
+    "future",
+    "lxml",
+    "pymavlink",
+    "pyserial",
+    "ptyprocess",
+    "pexpect",
+    "setuptools<81",  # older ArduPilot build scripts need the legacy pkg_resources module
+    "empy==3.3.4",
+]
+
+
+def _install_ardupilot_prereqs() -> None:
+    """Install just what's needed to configure/build SITL and generate MAVLink headers.
+
+    ArduPilot's own Tools/environment_install/install-prereqs-ubuntu.sh (as
+    pinned at ARDUPILOT_REF) predates Ubuntu 24.04 "noble" support and also
+    pulls in a large MAVProxy/wxPython/SFML stack only needed for its
+    graphical GCS console - `sim gazebo drone` runs the `arducopter` binary
+    directly (not sim_vehicle.py/MAVProxy), so none of that is needed here.
+    """
+    _run(["sudo", "apt-get", "update"], cwd=ARDUPILOT_DIR)
+    _run(
+        ["sudo", "apt-get", "install", "-y", "--no-install-recommends", *_BUILD_APT_PACKAGES],
+        cwd=ARDUPILOT_DIR,
+    )
+    _run(
+        ["pip3", "install", "--break-system-packages", *_BUILD_PIP_PACKAGES],
+        cwd=ARDUPILOT_DIR,
+    )
+
+    env = os.environ.copy()
+    user = env.get("USER") or getpass.getuser()
+    _run(["sudo", "usermod", "-a", "-G", "dialout", user], cwd=ARDUPILOT_DIR)
+
+
+def _pin_waf_for_python312() -> None:
+    waf_dir = ARDUPILOT_DIR / "modules" / "waf"
+    result = subprocess.run(  # noqa: S603
+        ["git", "rev-parse", "HEAD"], cwd=waf_dir, capture_output=True, text=True, check=False
+    )
+    if result.stdout.strip() == ARDUPILOT_WAF_COMMIT:
+        info("modules/waf already pinned to the Python 3.12-compatible commit")
+        return
+    _run(["git", "fetch", "--depth", "1", "origin", ARDUPILOT_WAF_COMMIT], cwd=waf_dir)
+    _run(["git", "checkout", ARDUPILOT_WAF_COMMIT], cwd=waf_dir)
+
+
+# ARDUPILOT_REF predates GCC 13 (Ubuntu 24.04's default): some files rely on
+# standard headers transitively including <cstdint>/<cstring>, which newer
+# libstdc++ no longer does. Each entry adds a missing include right before
+# an existing one, purely a header fix with no behavior change. Extend this
+# list if `./waf copter` hits more "does not name a type" errors.
+_GCC13_HEADER_FIXES: list[tuple[str, str, str]] = [
+    (
+        "libraries/AP_HAL_SITL/CANSocketIface.cpp",
+        "#include <linux/can/raw.h>",
+        "#include <cstdint>",
+    ),
+]
+
+
+def _patch_gcc13_headers() -> None:
+    for rel_path, anchor, missing_include in _GCC13_HEADER_FIXES:
+        path = ARDUPILOT_DIR / rel_path
+        text = path.read_text()
+        if missing_include in text:
+            continue
+        path.write_text(text.replace(anchor, f"{anchor}\n{missing_include}", 1))
+
+
+def _build_arducopter() -> None:
+    if ARDUCOPTER_BIN.is_file():
+        info(f"ArduCopter SITL already built at {ARDUCOPTER_BIN}")
+        return
+    _pin_waf_for_python312()
+    _patch_gcc13_headers()
+    _run(["./waf", "configure", "--board", "sitl"], cwd=ARDUPILOT_DIR)
+    _run(["./waf", "copter"], cwd=ARDUPILOT_DIR)
+    if not ARDUCOPTER_BIN.is_file():
+        die(f"Build finished but {ARDUCOPTER_BIN} was not produced")
+
+
+def _clone_ardupilot_gazebo() -> None:
+    if ARDUPILOT_GAZEBO_DIR.is_dir():
+        info(f"ardupilot_gazebo already cloned at {ARDUPILOT_GAZEBO_DIR}")
+        return
+    ARDUPILOT_GAZEBO_DIR.parent.mkdir(parents=True, exist_ok=True)
+    _run(
+        ["git", "clone", ARDUPILOT_GAZEBO_REPO, str(ARDUPILOT_GAZEBO_DIR)],
+        cwd=ARDUPILOT_GAZEBO_DIR.parent,
+    )
+
+
+_GAZEBO_PLUGIN_APT_PACKAGES = [
+    "libgstreamer1.0-dev",
+    "libgstreamer-plugins-base1.0-dev",
+]
+
+# ardupilot_gazebo's CMakeLists.txt calls ament_package(), which needs catkin_pkg
+# (to parse package.xml) on whatever python ROS2's ament_cmake_core invokes.
+_GAZEBO_PLUGIN_PIP_PACKAGES = ["catkin_pkg"]
+
+
+def _build_ardupilot_gazebo_plugin() -> None:
+    if ARDUPILOT_GAZEBO_PLUGIN.is_file():
+        info(f"ardupilot_gazebo plugin already built at {ARDUPILOT_GAZEBO_PLUGIN}")
+        return
+    _run(["sudo", "apt-get", "update"], cwd=ARDUPILOT_GAZEBO_DIR)
+    _run(
+        [
+            "sudo",
+            "apt-get",
+            "install",
+            "-y",
+            "--no-install-recommends",
+            *_GAZEBO_PLUGIN_APT_PACKAGES,
+        ],
+        cwd=ARDUPILOT_GAZEBO_DIR,
+    )
+    _run(
+        ["pip3", "install", "--break-system-packages", *_GAZEBO_PLUGIN_PIP_PACKAGES],
+        cwd=ARDUPILOT_GAZEBO_DIR,
+    )
+    env = os.environ.copy()
+    env["GZ_VERSION"] = "harmonic"
+    _run(
+        ["cmake", "-B", "build", "-DCMAKE_BUILD_TYPE=RelWithDebInfo"],
+        cwd=ARDUPILOT_GAZEBO_DIR,
+        env=env,
+    )
+    _run(
+        ["cmake", "--build", "build", "--parallel", str(os.cpu_count() or 1)],
+        cwd=ARDUPILOT_GAZEBO_DIR,
+        env=env,
+    )
+    if not ARDUPILOT_GAZEBO_PLUGIN.is_file():
+        die(f"Build finished but {ARDUPILOT_GAZEBO_PLUGIN} was not produced")
+
+
+def setup() -> None:
+    """Clone and build ArduPilot SITL (ArduCopter) and the ardupilot_gazebo plugin"""
+    if is_installed():
+        info("ArduPilot SITL + ardupilot_gazebo plugin are already set up")
+        info(f"  {ARDUCOPTER_BIN}")
+        info(f"  {ARDUPILOT_GAZEBO_PLUGIN}")
+        return
+
+    try:
+        run_step("Cloning ArduPilot", _clone_ardupilot)
+        run_step("Installing ArduPilot build prerequisites", _install_ardupilot_prereqs)
+        run_step("Building ArduCopter SITL (this takes a while)", _build_arducopter)
+        run_step("Cloning ardupilot_gazebo", _clone_ardupilot_gazebo)
+        run_step("Building ardupilot_gazebo plugin", _build_ardupilot_gazebo_plugin)
+    except subprocess.CalledProcessError as error:
+        die(f"Command failed with exit code {error.returncode}: {' '.join(error.cmd)}")
+
+    info("ArduPilot SITL + ardupilot_gazebo plugin are ready")
+    info("Run 'sim gazebo drone' to launch the drone simulation")

cli/gazebo/launch.py

@@ -15,6 +15,41 @@
 _ANSI_RE = re.compile(r"\x1B\[[0-9;]*[mK]")
 
 
+def _robot_type(robot_name: str) -> str | None:
+    from .create.registry import load_robots_json
+
+    entry = next((e for e in load_robots_json() if e["name"] == robot_name), None)
+    return entry.get("type") if entry else None
+
+
+def _configure_ardupilot_env(robot_name: str, env: dict[str, str]) -> None:
+    """For ArduPilot-type robots, point Gazebo at the plugin/models built by
+    `sim gazebo setup-drone` and expose the SITL binary path to the launch file."""
+    if _robot_type(robot_name) != "ardupilot":
+        return
+
+    from . import ardupilot
+
+    if not ardupilot.is_installed():
+        die(
+            "ArduPilot SITL + ardupilot_gazebo plugin are not built yet.\n"
+            "        Run: sim gazebo setup-drone"
+        )
+
+    for var, paths in (
+        (
+            "GZ_SIM_RESOURCE_PATH",
+            [ardupilot.ARDUPILOT_GAZEBO_DIR / "models", ardupilot.ARDUPILOT_GAZEBO_DIR / "worlds"],
+        ),
+        ("GZ_SIM_SYSTEM_PLUGIN_PATH", [ardupilot.ARDUPILOT_GAZEBO_BUILD_DIR]),
+    ):
+        existing = [p for p in env.get(var, "").split(":") if p]
+        additions = [str(p) for p in paths if str(p) not in existing]
+        env[var] = ":".join(additions + existing)
+
+    env["ARDUCOPTER_BIN"] = str(ardupilot.ARDUCOPTER_BIN)
+
+
 def in_pixi() -> bool:
     return bool(os.environ.get("PIXI_PROJECT_ROOT") or os.environ.get("CONDA_PREFIX"))
 
@@ -180,6 +215,7 @@ def build_and_launch(robot_name: str, *, build_only: bool = False, no_build: boo
     launch = not build_only
     env = os.environ.copy()
     render_prefix = _configure_force_vnc_rendering(env)
+    _configure_ardupilot_env(robot_name, env)
     bringup_pkg, description_pkg, launch_file_name = _validate_robot_layout(robot_name)
 
     if build:

cli/paths.py

@@ -33,6 +33,10 @@ def _find_repo_root() -> Path:
 NATIVE_ENV_PREFIX = NATIVE_ENVS / "ros_env"
 NATIVE_CONTROL_WS = NATIVE_BUILD_DIR / "gz_ros2_control_ws"
 
+# ArduPilot SITL + ardupilot_gazebo plugin, built by `sim gazebo setup-drone`
+ARDUPILOT_DIR = NATIVE_BUILD_DIR / "ardupilot"
+ARDUPILOT_GAZEBO_DIR = NATIVE_BUILD_DIR / "ardupilot_gazebo"
+
 MACOS_SOURCE_FILES = GAZEBO_WORKSPACE_DIR / "sim_common" / "macos"
 MACOS_MAMBA_ROOT = NATIVE_BUILD_DIR / "mamba"
 MACOS_ROS_BASE = NATIVE_BUILD_DIR / "ros_base"

docker/docker-compose-gpu.yml

@@ -14,5 +14,5 @@ services:
 
     command: >-
       bash -lc 'set -e;
-      python3 -m venv .venv && source .venv/bin/activate && pip install -e . && \
+      python3 -m venv .venv && source .venv/bin/activate && pip install -e . &&
       exec sleep infinity'

docker/docker-compose.yml

@@ -15,6 +15,7 @@ services:
 
     environment:
       DISPLAY: "${DISPLAY:-:0}"
+      XAUTHORITY: "${XAUTHORITY:-}"
       VNC_PORT: "${VNC_PORT:?VNC_PORT must be set, see docker/.env}"
       NOVNC_PORT: "${NOVNC_PORT:?NOVNC_PORT must be set, see docker/.env}"
       ROSBRIDGE_PORT: "${ROSBRIDGE_PORT:?ROSBRIDGE_PORT must be set, see docker/.env}"

docs.config.json

@@ -31,7 +31,8 @@
                     "label": "Robot Packages",
                     "slug": "gazebo/robot-packages"
                 },
-                { "label": "Joint GUI", "slug": "gazebo/joint-gui" }
+                { "label": "Joint GUI", "slug": "gazebo/joint-gui" },
+                { "label": "Drone (ArduPilot SITL)", "slug": "gazebo/drone" }
             ]
         },
         {