Yes, you can find their repo here. It is MIT Licensed so should work about the same as Apache License, but it won’t be Apache.
I hate when these companies bury their “community” editions on their website.
They do mention it on pages where they describe their proprietary Cloud and Enterprise options that InfluxDB itself is open source. And it is part of most of the Linux Distro package management systems.
I personally run their Docker image from Docker Hub.
And like I said before, I mainly brought it up as an example to look at, not as an alternative to Graphite, though if you find it worth consideration I’ll consider my comment doubly useful.