Grafana-server Init Failed: Could not find config defaults, make sure homepath command line parameter is set or working directory is homepath

This error is, I think,  a generic error.
In my case, the problem was that the postgresql server was not accepting the connection that the grafana server required.

Adding the homepath did help as it generated the actual error which was causing the issue:
/usr/sbin/grafana-server --pidfile=/var/run/grafana-server.pid --config=/etc/grafana/grafana.ini --homepath=/usr/share/grafana cfg:default.paths.data=/var/lib/grafana cfg:default.paths.logs=/var/log/grafana cfg:default.paths.plugins=/var/lib/grafana/plugins