[ros2component] Add tests for ros2component

[BMarchi]

As the title says, this PR adds tests for the ros2component cli. It's lacking tests for the standalone verb and opensplice is returning a different code error that needs further investigation.
I wasn't able to separate all the verbs because the container is kept alive for every test case and I'm not sure if we can rerun the container each time a test is run.

• Linux
• Arch
• OSX

[hidmic]

@BMarchi consider splitting this test into multiple launch tests, each can then setup the fixture appropriately e.g. preload components into the container before testing unload or list.

[BMarchi]

Something to notice is that these tests don't run with opensplice. It always hangs for almost all verb conditions which ends up failing every test. I suggest to create an issue for opensplice only.

[hidmic]

Left some comments!

[hidmic]

@BMarchi if you check container output, you don't even have to publish.

[BMarchi]

I can't see why I don't have to publish, can you explain? The container process is the one who gets the output

[hidmic]

I mean you can simply check the output the container generates on component load, no need for the component to generate extra output or even have any logic beyond these tests' purposes.

[BMarchi]

Currently I'm dealing with the standalone verb extension. There's an issue with launch regarding the process that runs the standalone verb in opensplice . It just ignores the sigint signal, which escalates to sigterm and leaves the process alive. For fastrtps I had to resend a sigint signal in the except portion here so it can kill the process properly. I'm still investigating this behavior.

[BMarchi]

I wasn't able to find out the reason of why standalone tests are finishing without killing the process launched. For FastRTPS I was able to wipe out the processes by re sending the SIGINT signal here when a keyboard interrupt ocurrs, making sure that the process is still alive before sending it again. But for opensplice, the process is always alive (it's ignoring the SIGINT signal completely).