add more commands

[dirk-thomas]

This PR adds some more commands:

• Add the command ros2 msg with the verbs list, package, packages, and show
• Add the command ros2 srv with the verbs list, package, packages, and show
• Add the command ros2 run

The CI builds are again not really saying much (beside that the linter tests for the new code are passing):

• Linux
• Linux-aarch64
• macOS
• Windows

Ready for review.

[mikaelarguedas]

is it on purpose that none of the new packages run the pep257 test ?

[dirk-thomas]

Yes, pep257 linting is provided by a flake8 plugin.

[mikaelarguedas]

I don't think we ever installed this plugin because not available from debian packages (only via pip like import-order). Can't find any trace of it in the ci scripts either... Is there a PR I missed that was adding it ?

[dirk-thomas]

Should we install flake8-docstrings in the CI jobs then (as we do for flake8-import-order)? Or should we add pep257 tests explicitly?

[mikaelarguedas]

flake8-docstrings is not available via apt so I'd lean towards using pep257 explicitely as we do everywhere else. But I don't feel very strongly about it.

[dirk-thomas]

Sounds good to me. I will add them for all packages in this repo.

[dirk-thomas]

I updated this PR and created #5 for the already merged packages.

[mikaelarguedas]

That's pretty cool!

While testing a few things surprised me:

• ros2 msg:
  • ros2 msg show expects "PackageName MessageName" but ros2 msg list gives me "PackageName/MessageName". So that means we cant copy paste the result of list to use show. It both differ from rosmsg in ros1 and is less convenient
• ros2 run
  • run doesn't complete executable name so I need to know the package and the name to be able to run a node.
  • if I pick an executable it cannot find it:

$ros2 run examples_rclcpp_minimal_publisher examples_rclcpp_minimal_publisher_lambda
No executable found

Same terminal

$ examples_rclcpp_minimal_publisher_lambda
Publishing: [Hello, world! 0]
Publishing: [Hello, world! 1]

[dirk-thomas]

ros2 run looks in the package specific libexec folder (<prefix>/share/lib/<pkgname>) for executables. Since non of our current packages installs any executables there you won't get any completion result.

Regarding ros2 msg: I usually prefer to pass information atomically. Otherwise e.g. your completion list for the combined argument would be extremely long. So I am not sure if we should change it to be the same as in ROS 1 or update the ros2 msg list output to print both parts (the package name and message name) separately.

[dirk-thomas]

Updated. See https://github.com/ros2/ros2cli/pull/3/files#diff-c2d4477e31b61377c91386997085d179R24 and https://github.com/ros2/ros2cli/pull/3/files#diff-c351f7ddc76367ae3cf77f70feede99cR24

[mikaelarguedas]

Great! thanks foor iterating on this, lgtm

[mikaelarguedas]

Note: I tried to install my executables in lib but couldn't get them to run No executable found. Also not sure how we should install ament_python packages now, but all this can be discussed/addressed after beta2

[dirk-thomas]

Did you install the executables in lib (which is the wrong location) or lib/<pkgname>? When I tried the code it worked for the later location.

[wjwwood]

I got it to work with this patch to demo_nodes_cpp:

diff --git a/demo_nodes_cpp/CMakeLists.txt b/demo_nodes_cpp/CMakeLists.txt
index 0e4f484..f6b0034 100644
--- a/demo_nodes_cpp/CMakeLists.txt
+++ b/demo_nodes_cpp/CMakeLists.txt
@@ -22,7 +22,7 @@ function(custom_executable subfolder target)
     "rcutils"
     "std_msgs")
   install(TARGETS ${target}
-    DESTINATION bin)
+    DESTINATION lib/${PROJECT_NAME})
 endfunction()

 # Tutorials of Publish/Subscribe with Topics

[wjwwood]

lgtm, with one error case that could be handled better

[wjwwood]

What if this is None?

[wjwwood]

I get this:

% ros2 run taco talker
Failed to load entry point 'service': No module named 'ros2service.command.service'
Traceback (most recent call last):
  File "/Users/william/ros2_ws/install/bin/ros2", line 11, in <module>
    load_entry_point('ros2cli', 'console_scripts', 'ros2')()
  File "/Users/william/ros2_ws/build/ros2cli/ros2cli/cli.py", line 64, in main
    rc = extension.main(parser=parser, args=args)
  File "/Users/william/ros2_ws/build/ros2run/ros2run/command/run.py", line 50, in main
    executable_name=args.executable_name)
  File "/Users/william/ros2_ws/build/ros2run/ros2run/api/__init__.py", line 45, in get_executable_path
    paths = get_executable_paths(node=node, package_name=package_name)
  File "/Users/william/ros2_ws/build/ros2run/ros2run/api/__init__.py", line 30, in get_executable_paths
    base_path = os.path.join(prefix_path, 'lib', package_name)
  File "/usr/local/Cellar/python3/3.6.0/Frameworks/Python.framework/Versions/3.6/lib/python3.6/posixpath.py", line 78, in join
    a = os.fspath(a)
TypeError: expected str, bytes or os.PathLike object, not NoneType

[dirk-thomas]

Fixed: 1232edf609ceaef883221a503ec35a34b6343731

[wjwwood]

Now it says No executable found, which to be more accurate, the package was not found. It would be better if it said that.

% ros2 run taco talker
No executable found