Sub-Apps and Reconfiguring exsting apps

Sub-Apps are a term we use for providing variants of existing apps. They act as a child to the existing parent application. That is, they inheret all the options and scripts from the existing application and override some or all of options.

You may want to do this to provide variants of existing apps.

In fact, this is how the bc_desktop application works. Open OnDemand ships the base app and sites provide sub apps with configurations specific to their site.

The way it works is this: Let’s say you have an existing application in /var/www/ood/apps/sys/my_app.

You have 2 options for supplying sub-app overrides.

  • Place new form.yml files in /etc/ood/config/apps/my_app.

  • OR provide new form.yml files in /var/www/ood/apps/sys/my_app/local.

There are pros and cons to each scheme. With the former, you sperate the overriedes (the sub-apps) and the actuall app. The subapps residing in /etc/ood and the actual apps residing in /var/www. This would allow you to update one without having to update the other.

With latter scheme you keep the overrides with the main application itself. This has the benefit of having everything in the same place, perhaps a git repository so that the apps (the main app and the sub-app) get updated together.

Quick Launch Apps

Quick launch apps are a special version of Sub-Apps that have all their from options with hard coded values. Indeed, they’re not really options at all as users will not be able to choose anything.

Let’s see an example for my_app.

Here we have the regularly defined form for this application and it has choices for the account to use and the amount of cores to request.

# /var/www/ood/apps/sys/my_app/form.yml

# the cluster(s) this app can submit jobs to.
cluster: "owens"

# 'form' is a list of form choices for this app. Here we're allowing users to set
# the account and the number of cores they want to request for this job.
  - bc_account
  - cores

This will allow users to choose their account and cores.

However, if we use preset values, users only need to click the icon to submit the job. That is, they will not be given the form to fill out choices, they will simply submit the job directly with the values that the administrator has chosen for them.

# /var/www/ood/apps/sys/my_app/local/preset.yml
# or
# /etc/ood/config/apps/my_app/preset.yml

# the cluster(s) this app can submit jobs to.
cluster: "owens"

# this form has values set in the attributes section for all form items.
# so users will submit a job with account abc123 and request 1 core without
# being presented with any choice.
  - bc_account
  - cores
    value: 'abc123'
    value: 1

Now users will be presented with both variants. My App and My App: preset. The system used the name preset based on the name of the file.