All, I am running a smarthome with fhem.de since 2012 and I am looking to move to HA for years now, but I am still with fhem because of many existing devices which are not supported by HA e.g. FS20 switches, FHT-80 thermostats among others.
Anyway as I already have my whole setup running on a x86-based Gigabyte Mini-PC with Ubuntu Server and other docker images (evcc.io, Z2M, Mosquitto, Homebridge, …), I am running HA as a docker image, too. I understand, that supervisor mode and the addon store is not supported in this setup or even not possible. As I am new to HA, I am interested in the “why”? And do you have any suggestions for me what you would do in my place if you want to use components that are only available in the addon store? Thanks in advance
Like…?
You can use addons running HA as a container, only that you have to manage them manually. Supervised mode will install, uninstall and back them up easily through HA itself.
Advanced installation methods will give you for more info.
Home Assistant Container is one of several official installation methods that allows you to run a docker-based version of Home Assistant on a Linux distro of your choice. You can install whatever other docker-based applications you want.
Home Assistant Supervised is an installation method that runs a docker-based version of Home Assistant exclusively on Debian and incorporates a Supervisor container that serves as a system manager. Addons are docker-based applications but designed to work exclusively with Supervisor; they don’t work with Home Assistant Container (which has no Supervisor).
In addition, if you install other docker containers, Supervisor will detect them. Certain docker-based applications (Portainer, Watchtower, etc) will cause Supervisor to mark your system as Unsupported, meaning your system is no longer eligible for official support from the development team, or Unhealthy which prevents you from upgrading until you fix the incompatibility.
Home Assistant OS is an installation method that is like Home Assistant Supervised but comes with its own streamlined operating system. This is the most popular installation method.
Correcting based on what Taras said. Running on Docker you cannot have HA addons. The closest you can get is by running containers that mimic the functions of addons, if possible.
There are very, very few add-ons that you can’t find an equivalent stand-alone docker container for. If you already know docker then it shouldn’t be much of an issue for you.
e.g. the openWakeWord, or did I miss something or understood it wrong? As said I am quite new to HA, but want to stay 
You can load a container for that.
https://community.home-assistant.io/t/loading-a-custom-wake-word-in-docker-compose/645081
Thanks, all, for your replies. With your feedback and what I realized in another thread, the code below is a very first step to go. At least I can see the “addons” in the left panel. I will now investigate how to interact with them … and I will surely look deeper into @tom_l s hint
panel_iframe:
portainer:
title: 'Portainer'
url: 'http://192.168.2.222:9000'
icon: mdi:docker
evcc:
title: 'evcc'
url: 'http://192.168.2.222:7070'
icon: mdi:docker