Compiling AngularJS interface

NodeJS version should be >=12.0.0 and <=12.14.1 (tested, but probably works on anything >=12).

As root:

On Ubuntu:

   Install nodejs version 12 from: https://www.digitalocean.com/community/tutorials/how-to-install-node-js-on-ubuntu-18-04

On Debian based systems:

   apt-get install nodejs

On Redhat based systems:

   curl --silent --location https://rpm.nodesource.com/setup_6.x | bash -
   yum install nodejs

Then:

   cd /opt/enswitch/current/web
   npm install
   npm install -g bower
   npm install -g gulp
   ln -s /usr/bin/nodejs /usr/local/bin/node
   bower --allow-root install
   gulp build

Apache can now serve from /opt/enswitch/current/web/dist/.

Alternatively you can run a development version using "gulp serve". You should use the URL on port 3000, and allow access to it through the firewall.