Runtime environment

When the Supervisor starts your app, it sets up the container with a few things your code can count on. This page lists them.

Variable	Contents
SUPERVISOR_TOKEN	The token of your app, for the Supervisor API and the Home Assistant Core API proxy. Unique per app.
HASSIO_TOKEN	The same token, under its old name. Use SUPERVISOR_TOKEN in new code.
TZ	The time zone of the system, like Europe/Amsterdam.

Your own variables from environment in config.yaml are added too. With legacy: true, the top-level options that are a string or a number are also passed as variables.

The base images use S6 overlay, which keeps the environment of the container in a separate place. Scripts that start with #!/command/with-contenv bashio (or with-contenv bash) get these variables; other scripts started by S6 may not. See the container environment.

Path	Contents
/data	The private, persistent storage of your app. Read and write, included in backups.
/data/options.json	The options of the user, validated against your schema. Written before every start.

Folders you map with map are mounted at these paths, unless you set a different path:

Type	Path
homeassistant_config	/homeassistant
app_config	/config
all_app_configs	/app_configs
local_apps	/local_apps
ssl	/ssl
share	/share
media	/media
backup	/backup

Mapped folders are read-only unless you set read_only: false.

Depending on other keys in config.yaml, the Supervisor mounts more:

Key	Mounted
tmpfs: true	/tmp as tmpfs, in memory
host_ipc: false	A private /dev/shm, in memory
audio: true	/etc/pulse/client.conf, /run/audio, and /etc/asound.conf
devicetree: true	/device-tree
gpio: true	/sys/class/gpio, on systems that support it
udev: true	/run/udev, read-only
kernel_modules: true	/lib/modules, read-only
host_dbus: true	/run/dbus, read-only
journald: true	/var/log/journal and /run/log/journal, read-only
docker_api: true	/run/docker.sock, read-only, only with protection mode off

Unless you set host_network, your app runs on an internal network, 172.30.32.0/23, together with the Supervisor and the other apps. Home Assistant Core is reachable from it too.

Name	What it is
supervisor	The Supervisor, with its API. Always 172.30.32.2. hassio is an alias.
homeassistant	Home Assistant Core. It runs on the host network and is reachable at 172.30.32.1, the gateway of the internal network.
{repository}-{slug}	Another app, like core-mosquitto or local-hello-world.

The host name of your own container is your app ID with _ replaced by -. With host_uts: true, it is the host name of the host instead.

supervisor and hassio are added to the hosts file of your container, so they also work on the host network. An app on the host network is still registered by name in the internal DNS, pointing to the gateway 172.30.32.1, so other apps reach it by name as well.

Ingress requests always come from the Supervisor, 172.30.32.2.

The Home Assistant base images use S6 overlay as their init system, with /init as the entrypoint. Set init: false in config.yaml so Docker does not add its own init process in front of it. See Run services with S6 overlay.