labwork-docker

This is a thin shim of code around a submission system. It starts Docker containers for each student's submission in an isolated container, build and runs them.

Installation of the Docker container

If you want to use the Docker container as it is built by the CI system, you can simply:

$ docker pull ghcr.io/johndoe31415/labwork-docker:master

Then you can tag it as 'labwork' so it's automatically found by the binary:

$ docker tag ghcr.io/johndoe31415/labwork-docker:master labwork

Building the Docker container

To build the Docker container yourself:

$ docker build docker -t labwork

To verify that the build was successful:

$ docker image ls labwork
REPOSITORY   TAG       IMAGE ID       CREATED        SIZE
labwork      latest    6e10dc886c2f   2 months ago   1.22GB

Submission file

The submission file has the following constraints:

It needs to be a .tar.gz archive
It needs to contain a "labwork" subdirectory which contains the submission
A build script may be present for compiling code
A run script must be present for running code. The run script receives an API endpoint as its first command line parameters and one or more additional command line parameters which are the exercises that it should query the labwork server for. The build script is called exactly once, the run script may be called multiple times.
The permissions of build and run need to be set appropriately (chmod +x).

An example labwork.tar.gz is included which answers a trivial assignment and which can be used as a stub for implementing more sophisticated clients.

Testing locally with network access

The run-testcases script is used to validate labwork submission files. It creates a Docker container, copies the .tar.gz file into it and executes it. When running untrusted code, the network connection is deliberately severed, but for testing purposes you can simply activate network access and direct your Docker container against a publicly available solution server.

You'll find an example solution file in labwork.tar.gz. To test this out against a public server at https://submissions.labserver.com/foobar/, you can simply execute:

$ ./run-testcases -n -a labwork01 -c 1889d4db-c5cc-4e47-80aa-48b3ff9bac3d -u https://submissions.labserver.com/foobar/ labwork.tar.gz
1 instances finished, 0 timed out. Collecting results.
labwork.tar.gz (064d78b5caa101765c58aad860ed7eef658601b4b50514b1b5a076701474ddd8): exit returncode 0
labwork/
labwork/run
labwork/build
labwork/my_solution.py
No build needed in this case (Python), this file is just an example.

Skipping build step, no 'build' file or not marked executable.
Do not know how to handle type: histogram
Do not know how to handle type: histogram
Do not know how to handle type: histogram
Do not know how to handle type: histogram
Do not know how to handle type: histogram
Do not know how to handle type: histogram
Do not know how to handle type: histogram
Do not know how to handle type: caesar_cipher
Do not know how to handle type: caesar_cipher
Do not know how to handle type: caesar_cipher
Do not know how to handle type: caesar_cipher
Do not know how to handle type: caesar_cipher
Do not know how to handle type: caesar_cipher
Do not know how to handle type: caesar_cipher
4 known assignments, 14 unknown.
Passed: 4. Failed: 0

You'll see that we executed the labwork01 exercise using client ID 1889d4db-c5cc-4e47-80aa-48b3ff9bac3d against https://submissions.labserver.com/foobar/. The handler only supports the simple strcat handler, other handlers are not implemented.

Testing with a proper CI/CD pipeline

The ideal way to build the artifact you need to hand in as your labwork is to have a custom pipeline that builds it automatically for every change in the code. This way, you can ensure that you're meeting all format criteria (e.g., permissions inside the .tar.gz archive, script layout). I can highly recommend you take a look at this. @arne-kapell has prepared a pipeline that already does this and which can be reused by everyone. Take a look at the documentation here. Note that this is not my code and I can give no warranties.

License

GNU GPL-3.