VScaler: HPCoD Horizon Integration

The Horizon specific Vscaler modifications are present in bitbucket repo : https://bitbucket.org/bostonhpc/vscaler-openhpc at path : vscaler-openhpc/HPC-on-Demand/horizon-contents/

The script at path vscaler-openhpc/Dockerfiles/horizon/template-overrides.j2 lists the steps required to integrate changes present in the repo with a bare bones Horizon installation on centos.

Basic tutorial about how dashboards work in Django and Horizon is present at https://docs.openstack.org/horizon/latest/contributor/tutorials/dashboard.html

Vscaler modification to Horizon consists of 1 Vscaler dashboard with 3 panel groups : HPC, Deep Learning and Big Data, with individual panels inside each panel groups.

The Big Data Panel is just Sahara Dashboard, with its allegiances changed. By default Sahara panelgroup is registered under Project dashboard, we just changed it to be registered under our custom Vscaler dashboard. Also, all the urls present in the Sahara code were modified with awk/sed to point under '/vscaler'.

The HPC and Deep Learning panel groups consist of a table shown on index page, with list of clusters and a workflow, which is just a multi-part form that creates a cluster. The original yaml scripts were converted into json objects and then made to fit in a nested json, which represents the whole cluster in 1 object, instead of many. This final json is passed to Horizon backend when the form is submitted, which in turn calls the Heat API and actually creates the cluster