How to Modify an Instrument Autoreduction Configuration Page

Note

This document is a draft. If you use the instructions, please consider correcting/improving them.

Instrument scientists can set up a form where Web Monitor users with staff status can modify the autoreduction script for the instrument. The web form lets the instrument scientists change parameter values in the autoreduction script and create a new version on the analysis cluster at

/SNS/<instrument>/shared/autoreduce/reduce_<instrument>.py

from where it is fetched by the postprocessing agent during autoreduction. Here is an example of the form for the instrument CNCS (can only be viewed by logged in users with staff or superuser status).

How to add a parameter to the configuration page

The following describes how an instrument scientist can add new parameters to an existing autoreduction configuration form. The instrument CNCS will be used as an example.

1. When the instrument scientist submits new parameter values in Web Monitor, a message containing a dictionary of key-value pairs is sent to the post-processing agent. The post-processing agent replaces the template variables (e.g. ${motor_names}) in reduce_<instrument>.py.template with values from the dictionary and writes a new version of reduce_<instrument>.py. To add a new parameter, first add the template variable to the template script:

On the analysis cluster, modify the template Python script for the instrument

/SNS/<instrument>/shared/autoreduce/reduce_<instrument>.py.template

to define the new templated variable and the logic using it, e.g.:

Motor_names="${motor_names}"
...
elog=ExperimentLog()
elog.setSERotOptions(Motor_names)

2. Add an entry with instrument, a parameter key/name and default value to the reduction properties model in the database using the Django administrative interface.

3. Make the parameter part of the configuration form by adding it as a field (e.g. FloatField) to the class ReductionConfigurationCNCSForm found in forms.py.

4. Make the parameter visible on the web page by adding the parameter and a descriptive label to the HTML template used to display the form in configuration_cncs.html.

5. Create a pull request to https://github.com/neutrons/data_workflow/tree/next.

6. When the change has been merged, a new release of Web Monitor should be created in GitHub. Once the release is available, work with the DevOps team to deploy the new release into production, see the deployment instructions.

How to test changes locally

Set up a local instance of Web Monitor by following the build instructions.

How to test in the test environment

TODO