In short, I finally got it to work.
In long I redid many things.
It seems the openhabian script succeeds to auto-install InfluxDB and Grafana, but it did not setup the users and their password.
It seems another issue was how to define localhost URL.
I believe the above 2 reasons are why autosetup script fails.
Finally your mentioned of http access was also missing (I previously followed an other tutorial which did not include that step).
I noticed whenever I ran sudo service influx status, there was no POST record.
After adding it, it seemed to work.
I might make a new tutorial one day, seeing as both influx and grafana are at much newer versions.
Quick follow-up question.
Can I use influxdb persist with a default strategy? (Example to save all items periodically).
Will the influxdb be used to re-set item states on reboot for example?
I previously had such a setup but I was not using influx, I was using the apache log file based persist (can’t remember the name).