generate_artifacts verb

[mikaelarguedas]

Python implementation of #82

Includes commits from #106 until it is merged.
Only third commit is relevant 5136c7d.

How to test it:

Generate the artifacts for /talker2 and all the identities in sample_policy.xml:

mkdir -p /tmp/sros2_demo && cd /tmp/sros2_demo
svn checkout https://github.com/ros2/sros2/trunk/sros2/test/policies
ros2 security generate_artifacts -k demo_keys -n /talker2 -p /tmp/sros2_demo/policies/sample_policy.xml

Run:

export ROS_SECURITY_ENABLE=true
export ROS_SECURITY_STRATEGY=Enforce
export ROS_SECURITY_ROOT_DIRECTORY=/tmp/sros2_demo/demo_keys
ros2 run demo_nodes_py listener &
ros2 run demo_nodes_cpp talker

killing the talker and running the following should also work:

ros2 run demo_nodes_cpp talker __node:=talker2

this should fail:

ros2 run demo_nodes_cpp talker __node:=talker3

The sros2 tutorial should still work as well

[mjcarroll]

Tested locally 👍, but haven't reviewed the code yet.

[mjcarroll]

Will also cover #106:

• Linux
• Linux-aarch64
• macOS
• Windows

[mikaelarguedas]

thanks @mjcarroll for the express reviews! 💯 🙇‍♂️

If you merge this and close #106, can you please "Create a merge commit" rather than "Squash and merge" to keep the commits separated?

Thanks!

[mjcarroll]

Helps that you were at the top of the inbox this morning. Will do after @ross-desmond gets a chance to comment on #106 (but I'm not anticipating any issues)