Test initializing parameters from command line

[sloretz]

Requires #272
Connects to ros2/rclcpp#488

This adds tests for parameters initialized via the command line arg __params:=/path/to/yaml.file

[wjwwood]

41a5dcc 👍

[mikaelarguedas]

lgtm,

I pushed a few nitpicks on init_params_via_yaml_mikael_review feel free to cherry-pick whatever is appropriate

a3687e2: alphabetical dependency order in package.xml
f36e85d: remove unused include
d2b7b76: call unused python loop control variable '_' for readability
4b8c886: reduce test tiemout, I have not see this test take more than a couple seconds on my machine so I supposed that using the default 60 second timeout should be enough
568a6d1: use some negative values for double testing

[sloretz]

@mikaelarguedas merged your branch into this one; thanks for the fixes!

[sloretz]

Limited CI to test if windows issue is fixed:

[sloretz]

Another rebuild to check if windows issue is fixed

[sloretz]

One more windows CI attempt

[sloretz]

Yet another windows CI attempt

[sloretz]

All platforms CI testing this package

• Linux
• Linux-aarch64
• macOS
• Windows

Major changes since review

[sloretz]

@mikaelarguedas here's a summary of the changes to this PR

1. Added custom NamedTemporaryFile class to util to work around issue with tempfile.NamedTemporaryFile() on windows
   • A temporary file on windows can't be opened by another process without closing it, but it can't be closed without being deleted. The workaround is to create a temporary directory with a normal file inside, then delete the whole directory on __exit__().
2. Got rid of asycnio and coroutines.
   • I was having trouble debugging the next issue, so I rewrote the tests using subprocess and threading
3. Every helper executable starts with a different node name
   • I'm not sure what the real bug is, but I don't have time to get to root cause right now. Here's what I know.
     • Every test does the following:
       1. spawns an executable with service server /initial_params_node/get_parameters
       2. creates a client for that service
       3. calls wait_for_service()
       4. calls the service and checks values of parameters returned
       5. destroys the client
       6. shuts down the executable
     • The first test to run passes, but the second test never gets a response from the service server.
     • The issue seems to be lower level than rclpy. The second test's client handle is in the wait set but never becomes ready. I did not check with wireshark to see if the request was actually sent.
     • It's definitely a race condition, adding time.sleep(1) after calling wait_for_service() but before calling the service in the second test solves the issue.
     • Reusing the same client for all tests does not solve the issue.
     • Giving each test a different node name (and therefor a different service name) works around the issue

[dirk-thomas]

The naming of this custom class is kind of confusing. It is the same as the one from the Python library but it behaves differently (doesn't return a file handle but the name). Therefore I would suggest to rename it to something more "custom" to avoid confusion.

[sloretz]

TemporaryFileWithContent in deb5998

[dirk-thomas]

I'm not sure what the real bug is, but I don't have time to get to root cause right now.

Please ticket this problem to investigate it in the future.

[sloretz]

Please ticket this problem to investigate it in the future.

ros2/ros2#502

[wjwwood]

lgtm, though I wonder if this could not have been done in rclcpp itself. But maybe there's a reason I missed. Also, why a new package and not just in test_rclcpp (maybe the dependency on rclpy)? Will this package also test the python API in the same way?

[wjwwood]

Seems like an unused dependency?

[sloretz]

@wjwwood The intent was to combine test_cli_remapping with testing parameters into test_cli, but #268 was merged first. I'll leave launch as a dependency for the moment and add it as a note to a ticket to combine the two test packages.

[sloretz]

Follow up ticket #279

[dirk-thomas]

The tests introduced in this PR are failing on the Windows debug nightly: https://ci.ros2.org/view/nightly/job/nightly_win_deb/906/