Apparently Pi-hole works on Armbian Orange Pi, so this is next step...
CoreElec is a Kodi JeOS with an Entware opkg package manager. Of course Kodi TV boxes are very popular and offer more hardware resources than Raspberry Pi for less price !
Issues highlighted don't just apply to CoreElec install, but to generic minimal OSes and to Docker install with minimal Alpine (5MB) base.
The main problem is that CoreElec is a read only OS and thus the /opt package installs are symlinked to the writeable /storage/.opt directory.
The other problem is that Docker install needs additional scripts, and Pi-hole 4.0 install on CoreElec Docker might not be possible yet. The Debian base for Docker is 120-130MB compared with the 50 MB Pi-hole itself, so this is not very efficient on a minimal OS anyway.
The idea of Docker with the usual OS distro base defeats the purpose of "lightweight and portable" and makes Docker more like a stunted VM !
I recall that the Pi-hole Docker Dev @diginc stated in another thread earlier that he abandoned his Alpine base effort because its use of musl instead of glibc caused incompatibilities. Don't know if any recent version upgrade for Pi-hole or Alpine can correct it.
Can we do Pihole install on this hardware with CoreElec OS ( Amlogic S905 1.5 Ghz quadcore aarch64 with Mali 450 pentacore 750 MHz GPU, and 1 GB RAM / 8 GB flash.)
Maybe the install.pi-hole.net script needs to be slightly modified ?
Regarding why the docker is only Debian, I'll add to your correct comment about musl libc adding some compatibility issues in the past. There's usually technical fixes to incompatibilities when you can control all pieces of the tech stack, the real reason was more stability and ease of developing updates. Focusing on Debian allowed me to make a single more usable / stable image.
That said, I have first hand experience waiting for my full image to download & extract on a RBPi and it's fairly excruciatingly long compared to a full blown x86 server's time with the exact same image size (due to hardware difference). At some point the Alpine image will be revisited, I don't think we're quite there yet, but I'll see about getting some focus on it for the future.
I did download Pi-hole on my Docker running on CoreElec v8.95.2 and their Linuxserver.io v1.0.5 but I don't know what version!
Also the GUI appears minimal- apart from ipv4/6 and web port 80 settings, and the password with the warning about port 53 to be open, I could only change the default DNS settings and check port 443 (I changed the password and checked port 443.)
I believe that image is a repackage of the official latest v4.0, other users of the same image reported problems using it. When looking into the reports I suspected they were because coreelec's docker was an older unofficial install but unfortunately I do not have the actual hardware to look into their problems.