Simply run node index to run node server. This will also generate angular configuration file and place it in client folder.
Configuration file is angular constant service with key value pairs for certain node env variables.
Process of injecting these values is done by gulp command: config.
Reference: https://medium.com/@kudresov/a-better-way-to-inject-environmental-variables-in-angular-d3b2d01a3c5e
gulp config takes config.json as default config and generates angular constant service.
It will inject all the configs from config.json.
If you want to override some of the value from the config or add new ones, add them to enviromental variables and
constants in configureSetup (gulpfile.js).