Enabling App Development

There are three steps to enabling app development:

  1. The PUN must have the config set so the app root looks to the path in the user’s home directory, or whatever per-user path dev apps should reside. This is configurable in the nginx_stage, though the default template string can be used as is.
  2. The Dashboard app needs to be informed that developer mode is enabled for the user, in order to show the Develop dropdown. By default, the Dashboard does this based on the existence of the path specified by OOD_DEV_APPS_ROOT which is set by taking the parent path of the interpolated value of app_root for dev apps (see the example nginx_stage.yml config file). There are also other options for configuring the Dashboard at the bottom of this page.
  3. Specify the development host, if it will differ from the default host for the shell app by setting it in OOD_DEV_SSH_HOST environment variable for the dashboard in the file /etc/ood/config/apps/dashboard/env. When developing apps, it is necessary to have access to the same versions of Ruby and NodeJS that are running on the OnDemand node. If the default ssh host is not the OnDemand node, then setting OOD_DEV_SSH_HOST to a host developers can ssh to with the same Software Collection (SCL) packages will help.

In OnDemand 1.3, the app root for a dev app was set in the PUN config to '~%{owner}/%{portal}/dev/%{name}'. This means for a user with the home directory /home/efranz in a default OnDemand install the root directory for the dev apps would be /home/efranz/ondemand/dev. If a user did mkdir -p ~/ondemand/dev and reloaded the Dashboard app, the Develop dropdown would appear and users could deploy apps in their home directory and launch them.

In OnDemand 1.4, the app root for a dev app has been changed to '/var/www/ood/apps/dev/%{owner}/gateway/%{name}'. So for user efranz this would be /var/www/ood/apps/dev/efranz/gateway/. To enable efranz to develop apps, the administrator can then do the following:

sudo mkdir -p /var/www/ood/apps/dev/efranz
cd /var/www/ood/apps/dev/efranz
sudo ln -s /home/efranz/ondemand/dev gateway

Then a user can create the dev directory in their home directory i.e. /home/efranz/ondemand/dev.

If you want to revert to the previous functionality of 1.3, where every user can run dev apps in their home directory, use the second example mapping here in the /etc/ood/config/nginx_stage.yml config file. If you do this, it is recommended that you treat the node that OnDemand is running on as a login node, as you are effectively giving those users shell access by letting them run arbitrary code on the OnDemand node (of course the UID of the processes are still their regular user UID).

By default the Dashboard will assume it is running in “Developer mode” if the dev apps root directory exists (specified by the environment variable OOD_DEV_APPS_ROOT). If you want to change this behavior, these are the options:

Table 8 Dashboard configuration for app development
Action Result
Set OOD_APP_DEVELOPMENT=1 in /etc/ood/config/apps/dashboard/env Developer mode will always be enabled in the Dashboard providing a Develop Dropdown. This can help with discoverability, as user’s do not need to create the dev root directory prior to seeing the Develop dropdown. This only makes sense if every user can develop apps.
Set Configuration.app_development_enabled to true based on one or more Ruby statements in /etc/ood/config/apps/dashboard/initializers/ood.rb

Code in the initializer runs as the user. This code also has access to the ood_support library in which we provide some helper classes to work with User’s and Groups.

If you want to restrict app development mode to group membership, you could do this:

Configuration.app_development_enabled = OodSupport::Process.groups.include?(
  OodSupport::Group.new(name: "devgrp")

Or if you know the id of the group, this will avoid reading the /etc/group file:

Configuration.app_development_enabled = Process.groups.include?(5014)

Or a specific user list:

Configuration.app_development_enabled = %w(
  bgohar efranz bmcmichael


The way app development is enabled is a bit clunky. We will be exploring other options to reduce the load on the admin in supporting app developers in the future. If you have any thoughts or ideas please share them on our Discourse instance.