prevent calling ros::init without name; use node_name command option instead of namespace

[furushchev]

Currently launching naoqi_driver_node without --namespace option causes mis-registering node name to ros master.

e.g. when launching by roslaunch pepper_bringup pepper_full.launch (ros_naoqi_driver is executed without --namespace option and under ns="pepper_robot"), the node name of ros_naoqi_driver is shown as //pepper_robot and ROS master cannot resolve address of this illegal ros node name.

$ rostopic info /cmd_vel
Type: geometry_msgs/Twist

Publishers: 
 * /teleop_twist_joy (http://133.11.216.136:44116/)
 * /pepper_1444291883382908575 (http://133.11.216.136:54125/) (Note: This is from pepper-interface.l)

Subscribers: 
 * //pepper_robot (unknown address //pepper_robot)  # this is invalid for ROS

Looking more deeply, I found that the value of command line option --namespace(https://github.com/ros-naoqi/naoqi_driver/blob/master/src/external_registration.cpp#L45) is passed to ros::init (https://github.com/ros-naoqi/naoqi_driver/blob/master/src/ros_env.hpp#L92) whose name must NOT be empty, so I added exception handler.
Also I'd like to point out that argument name --namespace is inappropriate and it is better to rename it to --node_name because the value of this option is passed to ros::init.

[k-okada]

k-okada@9425caa is another implementation for this issue.

[vrabaud]

why not using the ROS variable __name
http://wiki.ros.org/Remapping%20Arguments#Special_keys
http://wiki.ros.org/roscpp/Overview/Initialization%20and%20Shutdown#Initializing_the_roscpp_Node

[furushchev]

@vrabaud Thanks for advice. I agree that using __name is better. I fixed.

[vrabaud]

no need for that line anymore right ?

[vrabaud]

@furushchev , node_name is not a command line argument anymore right ? As we use the __name from ROS (that the launch file will implicitly set).
Therefore, there is no need for all_desc right ?

[Karsten1987]

as far as I know, there is no real API for fetching the __name parameter without calling ros::init.

That being said, here is a little function which parses the argc/argv pair for the __name argument.

std::string filterName( int argc, char** argv )
{ 
  for (size_t i=0; i<argc; ++i)
  {
    std::string arg(argv[i]);
    size_t pos = arg.find(":=");
    if (arg.substr(0,pos) == "__name")
    {
      return arg.substr(pos+2);
    } 
  } 
  return "";
} 

[furushchev]

@vrabaud Yes. It is actually hidden option, that's why I use 2 options_descriptions: desc for command line options (they are shown when with argument -h/--help), and all_desc (desc + node_name just for enabling external parser of __name)
Option node_name is not shown on --help.

[furushchev]

ping

[furushchev]

ping

[k-okada]

i think this PR contains two different things, to prevent error when no
namespace is given, and enable to change nodename (and use them for
namespace)
we should create two different PR for each of them.

◉ Kei Okada

On Fri, Oct 30, 2015 at 10:57 AM, Furushchev notifications@github.com
wrote:

ping

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[Karsten1987]

The PR got merged, so there is an official ros method ros::getROSArg now to parse any ROS argument.
Have a look at here ros/ros_comm@5db2088

[vrabaud]

Does that PR still make sense ? Please rebase first.

[Karsten1987]

ping?

[k-okada]

i think we can use #58 for
this issue, using command option instead of namespace may big change so we
need more discussion.

◉ Kei Okada

On Fri, Jan 8, 2016 at 4:28 PM, Karsten Knese notifications@github.com
wrote:

ping?

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