The client (NUC or Fixed Node) side of setting up an AERPAW experiment. Runs after the machine is re-imaged via PXE and controls downloading, running, and saving results from experiments. Also capable, under limited circumstances, of going out and getting barbeque sandwiches for the team.
A minimal web server (aerpawNodeControl.py) listens for HTTP GET requests on port 1887 (the year NCSU was founded, naturally). Basic workflow is
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Fetch the container. When an experiment is created, a user-supplied container is made available to the AERPAW reservation system. This is a tar file and is created by the user, in their own personal development server somewhere, doing a "docker save".
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Start the container running. Whatever the user specified as the ENTRYPOINT parameter will begin executing. An area of disk storage will be provided to the running container and mounted as "/data". As a good rule of thumb, don't write more than a few hundred gigabytes here without checking with the operations people first.
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Whether the container has finished running or not, the "emitDataVolume" command can be used to copy that container's private data filesystem directory back (as a tar file)
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Finally, even if the container has ceased running, call the "killContainer" command to shut down (if needed) and delete the container. A "docker prune" will be done to clean up any residue left behind. It's good to get in the habit of using this - if you're loading multiple containers and then running them all in one flight then disk space could run out otherwise.
/v1/fetchContainer/ContainerNameGoesHere - loads a snapshot of the desired container into the local docker
/v1/startContainer/ContainerNameGoesHere - starts the specified container running (docker run). Caution: if your container starts your experiment in the background (such as
ENTRYPOINT["myExperiment.sh &"]
(notice the ampersand?) then the container will exit immediately and it will be hard to know
when your experiment has completed. It's a good idea to not do that.
/v1/emitDataVolume/ContainerNameGoesHere - returns the contents of the directory that was mounted to the running container as /data. The contents of the resulting tar file is returned
as the HTTP payload (right after the header and the mandatory blank line, naturally).
/v1/deleteDataVolume/ContainerNameGoesHere - deletes the filesystem directory used for
the /data mount point. Handy for freeing up disk space if you're going to run more than one
experiment before landing and re-imaging the device.
/v1/killContainer/ContainerNameGoesHere - brings a swift and violent death to a running container and deletes all traces of it. It's the Sigourney Weaver Option.
This is one last line of text to test the switchover to rsa keys.