xsiftx

xsiftx is a program to run scripts against edx-platform data for a course or all courses and then writing that to the grade book s3 bucket to show up on the instructor dashboard.

The scripts can be anything that is executable and just need to output the filename they want to use as the first line, and the file contents as the rest. ie: student_report_20140207.csv name,datum johnsmith,things . . .

Sample usage to use the copy file sifter would something like: xsiftx -v /edx/app/edxapp/venvs/edxapp -e /edx/app/edxapp/edx-platform copy_file ~/test.jpg This would copy the test.jpg to every course available on the local LMS.

Writing sifters

Place whatever executable you like in the sifters folder in the repository and it will be added to the list of sifters for use in the command.

The expectations of sifters are that the first line output is the filename to use, and everything else on stdout is the file to upload to the dashboard.

You can write to stderr without consequence if neccessary, and returning anything but 0 will cause the upload to be aborted. Command is run with the following arguments: <sifter> edx_venv_path edx_platform_path course_id [extra_arg, extra_arg,....]

If you choose to write a sifter in python, there is a convenience function for loading into the edx-platform virtual environment and assuming the django settings inside the LMS. For examples that use this take a look at the content_statisics or future_grade_dump sifters. The notable lines are:

from xsiftx.tools import enter_lms
enter_lms(sys.argv[1], sys.argv[2])

As you can see, this basically allows you to write a django management command as though it were inside the platform without having to incoporate it directly into the code base.

This does require that GRADE_DOWNLOADS are turned on in your edx-platform install to show up. Sample settings for lms.env.json would look like:

    "GRADES_DOWNLOAD": {
        "BUCKET": "my-sample-bucket", 
        "ROOT_PATH": "term/grades", 
        "STORAGE_TYPE": "S3"
    },

with the following FEATURE flags set in that same file:

"ALLOW_COURSE_STAFF_GRADE_DOWNLOADS": true, 
"ENABLE_S3_GRADE_DOWNLOADS": true,

LTI Web Interface

There is now an LTI Web interface and service inside xsiftx for allowing course staff to run their own sifters on demand via a course component. It is quite simple to setup, and adds a lot of flexibility. The application offers fine grained access control to limit what sifters can be run by which users with a simple yaml based configuration file. It also uses celery to asynchronously manage jobs and the number of jobs that can be running at any given time.

To setup, create a configuration file at /etc/xsiftx.yml (or ~/.xsiftx.yml) and something similar to:

# LTI Test config
# The path to edx platform, defaults are shown below and if you have the same
# paths, they don't need to be specified
edx_venv_path: "/edx/app/edxapp/venvs/edxapp"
edx_platform_path: "/edx/app/edxapp/edx-platform"
flask_secret_key: "some_crazy_long_randomized_string_for_securing_client_cookies"
# What celery backend to use, redis is probably simplest,
# but rabbit works just as well
CELERY_BROKER_URL: "redis://"
CELERY_RESULT_BACKEND: "redis://"
# Here we define ACLs.  The key and secret are needed by the course team
# to add the LTI component to their courseware. Instructions at:
# http://ca.readthedocs.org/en/latest/exercises_tools/lti_component.html
consumers:
  - key: "testing"
    secret: "super_secret"
      allowed_sifters:
        - 'test_sifters'

So the course staff (instructor, course staff, or global staff) will only have access to run the "test_sifters" sifter with the above config.

To run the LTI application, use your favorite wsgi application server with xsiftx.web:app. For uwsgi, that would be something like uwsgi --http :5000 -w xsiftx.web:app, for gunicorn it would be: gunicorn xsiftx.web:app -b 0.0.0.0:5000. You will also need to start your celery worker to process jobs with something like: celery --app=xsiftx.lti worker -l info and you should be good to go. For production, you will want to put these into some type of startup file, and the application still needs to run on a system with edx-platform installed and the user running the workers will need access to the configuration files and code repository. You will likely also want to specify the number of workers allowed to run.

Sifters provided

Several sifters are provided in this repository:

• dump_grades -- dumps grades of all students to a CSV file. The grades can both be the aggregated grades (as defined by the edX graders configuration) or raw grades (un-aggregated grades for individual problems). Being able to dump raw grades can be very helpful to instructors who are debugging edX graders configurations.

• content_statistics -- dumps a CSV file with course content usage statistics, including, information about each module in the course, how many times it has been accessed, and now many times it has been attempted (for problems).

• copy_file -- Copies any arbitrary local file into the data download section

• xqanalyze -- Generates a zip file of CSVs where each CSV is a problem and each row in the CSV is a students response to that question. Applies only to capa problems.

• compute_grades -- Doesn't generate a report but does calculate grades for a course and stores them in the SQL data store for use by legacy dashboard actions.

• remote_grades -- Posts a course's grades to a remote gradebook specified in the the course's XML and as defined by the edx-platform feature flag REMOTE_GRADEBOOK_URL. It optionally takes an assignment name, but will post grades for every assignment if one isn't specified.

Adding additional sifters

In addition to the provided sifters, you can add additional sifters via a couple methods. The command searches for executable files first in the installation, then at a system location /usr/local/share/xsiftx/sifters, then in a user directory ~/sifters, then in your current directory $(cwd)/sifters, and finally by an environment variable SIFTER_DIR. The order of preference is first to last from above, so if you have a sifter with the same name in SIFTER_DIR and ~/sifters, the one in SIFTER_DIR would be what is called by xsiftx.