# Customization Overview¶

OnDemand’s configuration is stored in the environment, which can be modified using a hierarchy of config files. Configuration files are rooted in /etc/ood. Assets that should be publicly available (such as a favicon or logo image) are placed under /var/www/ood/public.

These are three files that directly affect the environment or functionality of the Per-User NGINX (PUN) processes:

• /etc/ood/config/nginx_stage.yml
• YAML file to override default configuration for the PUN. You can set environment variables via key-value pairs in the mapping pun_custom_env. You can specify a list of environment variables set in /etc/ood/profile to pass through to the PUN by defining the sequence pun_custom_env_declarations.
• An example of both of these uses may be found in nginx_stage_example.yml. Variables set here are set for all OnDemand applications.
• /etc/ood/config/apps/$APP/env • replace $APP above with the name of the app directory deployed to /var/www/ood/apps/sys
• Used to provide application specific config
• env files do not override values set by prior methods.
• /etc/ood/config/apps/$APP/initializers/ood.rb • replace $APP above with the name of the app directory deployed to /var/www/ood/apps/sys
• Modify Rails application behavior using Ruby code. Since this is application code environment variables can be set, removed.
• This method is specific to Ruby on Rails applications: Activejobs, Dashboard, and Job Composer. You can add multiple initializer files in this directory and they will be loaded in alphabetical order

This file affects the starting of the PUN, and is the appropriate place to change the software collections loaded:

• /etc/ood/profile

• Sourced as root prior to starting the PUN

• If exists, this file is sourced instead of the default at /opt/ood/nginx_stage/etc/profile by /opt/ood/nginx_stage/sbin/nginx_stage script when running as root, prior to launching the PUN.

• You should source /opt/ood/nginx_stage/etc/profile in your custom /etc/ood/profile if you add one to load the correct software collections.

• Environment variables set here are not guarenteed to remain set in the PUNs unless those environment variables are added to the YAML sequence pun_custom_env_declarations in /etc/ood/config/nginx_stage.yml. Here is a list of environment variables guarenteed to be preserved when NGINX starts:

• PATH
• LD_LIBRARY_PATH
• X_SCLS
• MANPATH
• PCP_DIR
• PERL5LIB
• PKG_CONFIG_PATH
• PYTHONPATH
• XDG_DATA_DIRS
• SCLS RUBYLIB