[N/a] fix for launching the driver without the gripper (#534)

## Change Overview

Having recently gotten access to a gripperless spot, I discovered some bugs that came from not correctly passing the gripperless parameter to SpotWrapper (this resulted in the robot trying to access gripper related servers and hanging). 

## Testing Done

- [x] driver now launches on a gripperless robot. Ran some simple trigger services to stand, sit, move arm, etc.

spot_driver/spot_driver/launch/spot_launch_helpers.py

@@ -3,7 +3,7 @@
 import logging
 import os
 from enum import Enum
-from typing import Any, Dict, List, Optional, Tuple
+from typing import Any, Dict, List, Literal, Optional, Tuple
 
 import yaml
 from launch.actions import DeclareLaunchArgument
@@ -13,6 +13,16 @@
 COLOR_END = "\33[0m"
 COLOR_YELLOW = "\33[33m"
 
+# The following constants are parameters we are interested in pulling from our config yaml file
+_USERNAME: Literal["username"] = "username"
+_PASSWORD: Literal["password"] = "password"
+_HOSTNAME: Literal["hostname"] = "hostname"
+_CERTIFICATE: Literal["certificate"] = "certificate"
+_PORT: Literal["port"] = "port"
+_CAMERAS_USED: Literal["cameras_used"] = "cameras_used"
+_GRIPPERLESS: Literal["gripperless"] = "gripperless"
+
+
 IMAGE_PUBLISHER_ARGS = [
     "depth_registered_mode",
     "publish_point_clouds",
@@ -151,16 +161,16 @@ def get_login_parameters(config_file_path: str) -> Tuple[str, str, str, Optional
 
     ros_params = get_ros_param_dict(config_file_path)
     # only set username/password/hostname if they were not already set as environment variables.
-    if not username and "username" in ros_params:
-        username = ros_params["username"]
-    if not password and "password" in ros_params:
-        password = ros_params["password"]
-    if not hostname and "hostname" in ros_params:
-        hostname = ros_params["hostname"]
-    if not port and "port" in ros_params:
-        port = ros_params["port"]
-    if not certificate and "certificate" in ros_params:
-        certificate = ros_params["certificate"]
+    if not username and _USERNAME in ros_params:
+        username = ros_params[_USERNAME]
+    if not password and _PASSWORD in ros_params:
+        password = ros_params[_PASSWORD]
+    if not hostname and _HOSTNAME in ros_params:
+        hostname = ros_params[_HOSTNAME]
+    if not port and _PORT in ros_params:
+        port = ros_params[_PORT]
+    if not certificate and _CERTIFICATE in ros_params:
+        certificate = ros_params[_CERTIFICATE]
     if (not username) or (not password) or (not hostname):
         raise ValueError(
             "One or more of your login credentials has not been specified! Got invalid values of "
@@ -177,6 +187,15 @@ def default_camera_sources(has_arm: bool, gripperless: bool) -> List[str]:
     return camera_sources
 
 
+def get_gripperless(ros_params: Dict[str, Any]) -> bool:
+    """Read the ros parameters to get the value of the gripperless parameter. Defaults to False if not set."""
+    gripperless = False
+    if _GRIPPERLESS in ros_params:
+        if isinstance(ros_params[_GRIPPERLESS], bool):
+            gripperless = ros_params[_GRIPPERLESS]
+    return gripperless
+
+
 def get_camera_sources_from_ros_params(ros_params: Dict[str, Any], has_arm: bool) -> List[str]:
     """Get the list of cameras to stream from. This will be taken from the parameters in the config yaml if it exists
     and contains valid cameras. If this list contains invalid cameras, fall back to the default of all cameras.
@@ -191,13 +210,10 @@ def get_camera_sources_from_ros_params(ros_params: Dict[str, Any], has_arm: bool
     Returns:
         List[str]: List of cameras the driver will stream from.
     """
-    gripperless = False
-    if "gripperless" in ros_params:
-        if isinstance(ros_params["gripperless"], bool):
-            gripperless = ros_params["gripperless"]
+    gripperless = get_gripperless(ros_params)
     default_sources = default_camera_sources(has_arm, gripperless)
-    if "cameras_used" in ros_params:
-        camera_sources = ros_params["cameras_used"]
+    if _CAMERAS_USED in ros_params:
+        camera_sources = ros_params[_CAMERAS_USED]
         if isinstance(camera_sources, List):
             # check if the user inputted any camera that's not in the default sources.
             invalid_cameras = [cam for cam in camera_sources if cam not in default_sources]
@@ -235,6 +251,7 @@ def spot_has_arm(config_file_path: str, spot_name: str) -> bool:
     """
     logger = logging.getLogger("spot_driver_launch")
     username, password, hostname, port, certificate = get_login_parameters(config_file_path)
+    gripperless = get_gripperless(get_ros_param_dict(config_file_path))
     spot_wrapper = SpotWrapper(
         username=username,
         password=password,
@@ -243,5 +260,6 @@ def spot_has_arm(config_file_path: str, spot_name: str) -> bool:
         cert_resource_glob=certificate,
         robot_name=spot_name,
         logger=logger,
+        gripperless=gripperless,
     )
     return spot_wrapper.has_arm()

spot_driver/spot_driver/spot_ros2.py

@@ -405,6 +405,7 @@ def __init__(self, parameter_list: Optional[typing.List[Parameter]] = None, **kw
                 continually_try_stand=self.continually_try_stand.value,
                 rgb_cameras=self.rgb_cameras.value,
                 cert_resource_glob=self.certificate,
+                gripperless=self.gripperless,
             )
             if not self.spot_wrapper.is_valid:
                 return