Home Assistant

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Revision as of 23:30, 4 January 2022 by imported>Krav (add example config for containerized version)

Home Assistant is an open source home automation software that puts local control and privacy first. Powered by a worldwide community of tinkerers and DIY enthusiasts.

Installation methods

Upstream has defined several installation methods which they are willing to support. The NixOS module is not one of them. When you find a problem you can still report it upstream, if you are certain that the issue is relevant to upstream supported installation methods as well. If not, or if in doubt, please open an isssue on the nixpkgs issue tracker or visit the NixOS Home-Automation (#nixos-homeautomation:lossy.network) Matrix room.

Virtual machine

You could run your Home Assistant in a virtual machine, with your NixOS host providing the hypervisor.

TODO: add example configuration

OCI container

You could run your Home Assistant in any kind of container runtime

Example Configuration

Adding the following to your `configuration.nix` will bring up home-assistant listening on `:8123` on the host interface.

{  
  virtualisation.oci-containers = {
    backend = "podman";
    containers.homeassistant = {
      volumes = [ "home-assistant:/config" ];
      environment.TZ = "Europe/Berlin";
      image = "ghcr.io/home-assistant/home-assistant:stable";
      extraOptions = [ 
        "--network=host" 
        "--device /dev/ttyACM0:/dev/ttyACM0"  # Example, change this to match your own hardware
      ];
    };
  };
}


NixOS Module

You could run home-assistant using the NixOS module system at services-home-assistant. As of 2021-11-28 we have roughly 70% of component dependencies packaged. There are two major ways of running home-assistant using the module system.

Declarative configuration

Set up your home-assistant by configuring the services.home-assistant.config attribute set as if it were your home-assistant YAML configuration. The module parses the root and platforms level to automatically discover integrations used and will add them to your home-assistant package. The following is a minimal starting configuration, that has all the dependencies that are required to complete the initial configuration flow, that creates your first user.

{

  services.home-assistant = {
    enable = true;
    # Good starting config, that will get you through the configuration
    # flow, that has a hard dependency on a few components.
    #
    # Components might not actually have YAML configuration, but
    # mentioning them in the configuration will get their dependencies
    # loaded.
    config = {
      # https://www.home-assistant.io/integrations/default_config/
      default_config = {};
      # https://www.home-assistant.io/integrations/esphome/
      esphome = {};
      # https://www.home-assistant.io/integrations/met/
      met = {};
    };
  };
}
Note: Sometimes configuration is only possible via Integrations, in that case the integration itself must be prepared in your declarative configuration. e.g. for WLED integration support: services.home-assistant.config.wled = {} ; is required

Reusing existing YAML configuration

The module also supports passing it an existing configuration, however that comes with certain drawbacks. For example we cannot automatically detect the components, that your configuration requires. In that scenario you will need to resolve dependencies manually using the packages extraComponents parameter. Also you will be unable to reuse configuration values between parts of your NixOS configuration. A barebones setup to get you started may look like this:

{
  services.home-assistant = {
    enable = true;
    # Pass the path to the directory where your configuration.yaml
    # resides, /var/lib/hass might be a good location.
    configDir = /var/lib/hass;
    # Override the package to handle dependency management manually
    package = (pkgs.home-assistant.override {
      # https://github.com/NixOS/nixpkgs/blob/master/pkgs/servers/home-assistant/component-packages.nix
      extraComponents = [
        "default_config"
        "esphome"
        "met"
      ];
      extraPackages = py: with py; [
        # Are you using a database server for your recorder?
        # https://www.home-assistant.io/integrations/recorder/
        #mysqlclient
        #psycopg2

      ];
    }).overrideAttrs (oldAttrs: {
      # Don't run package tests, they take a long time
      doInstallCheck = false;
    });
  };
}

You may find the following script helpful. It looks up missing dependencies from the home-assistant.service systemd unit journal: https://gist.github.com/AngryAnt/74c047a2b8438517c822ffdd9663aa57

Running a recent version using an overlay

Home Assistant is a fast-paced open source project, that currently features one major release every month, and a handful of minor ones in between. Firmwares and API endpoints tend to change from time to time, so Home Assistant and its bindings need to keep up to keep things work. The version we provide at the branch off is just a snapshot in time, and does not receive any updates, because there would just be too many dependencies to backport. But with NixOS it is still possible to use the version in nixpkgs/unstable by creating an overlay and using the module from nixos-unstable.

let
  # Track NixOS unstable via nix-channel, or replace it with something like niv at your own discretion
  # nix-channel --add http://nixos.org/channels/nixos-unstable nixos-unstable
  unstable = import <nixos-unstable> {};
in
{
  nixpkgs.overlays = [
    (self: super: {
      inherit (unstable) home-assistant;
    })
  ];

  disabledModules = [
    "services/misc/home-assistant.nix"
  ];

  imports = [
    <nixos-unstable/nixos/modules/services/misc/home-assistant.nix>
  ];
}

Snippets

Reverse Proxying with nginx

If you run a public Home Assistant instance it is a good idea to enable SSL/TLS. The following configuration generates a certificate using letsencrypt:

  services.home-assistant.config.http = {
    server_host = "::1";
    trusted_proxies = [ "::1" ];
    use_x_forwarded_for = true;
  };

  services.nginx = {
    recommendedProxySettings = true;
    virtualHosts."home.example.com" = {
      forceSSL = true;
      enableACME = true;
      extraConfig = ''
        proxy_buffering off;
      '';
      locations."/" = {
        proxyPass = "http://[::1]:8123";
        proxyWebsockets = true;
      };
    };
  };

Using PostgreSQL

Home Assistant supports PostgreSQL as a database backend for, among other things, its logger and history components. It's a lot more scalable and typically provides faster response times than the SQLite database, that is used by default.

Remember to make backups of your database, for Home Assistant is becoming more and more stateful and has moved away from a completely declarative YAML configuration for new and core components.

Also note that when overridding the package you may want to disable install checks as they tend to take a long time to complete.

  services.home-assistant = {
    package = (pkgs.home-assistant.override {
      extraPackages = py: with py; [ psycopg2 ];
    }).overrideAttrs (oldAttrs: {
      doInstallCheck = false;
    });
    config.recorder.db_url = "postgresql://@/hass";
  };

  services.postgresql = {
    enable = true;
    ensureDatabases = [ "hass" ];
    ensureUsers = [{
      name = "hass";
      ensurePermissions = {
        "DATABASE hass" = "ALL PRIVILEGES";
      };
    }];
  };

Add custom lovelace modules

There are many useful and pretty lovelace components out there that you might want to integrate into your dashboards. Some of them are packaged up inside NUR repositories.

Usually you would install these into /var/lib/hass/www, but that comes with issues on NixOS, as their internal webserver does not follow symlinks. You could then think about exposing that directory over your webserver, but you'll notice that your webserver user has no permissions to enter the home assistant users state directory, which is due to proper hardening on the home-assistant.service.

let
  # https://nur.nix-community.org/repos/mweinelt/
  nur = import (builtins.fetchTarball "https://github.com/mweinelt/nur-packages/archive/master.tar.gz") {};

  mkLovelaceModule = name: {
    # https://www.home-assistant.io/lovelace/dashboards-and-views/#resources
    url = "/local/${name}.js?${nur.hassLovelaceModules."${name}".version}";
    type = "module";
  };
in {
  # Install lovelace components into temporary directory that can be
  # served by nginx.
  systemd.tmpfiles.rules = [
    "d /run/hass 0700 nginx nginx"
    "L+ /run/hass/mini-graph-card.js - - - - ${nur.hassLovelaceModules.mini-graph-card}/mini-graph-card-bundle.js"
    "L+ /run/hass/mini-media-player.js - - - - ${nur.hassLovelaceModules.mini-media-player}/mini-media-player-bundle.js"
    "L+ /run/hass/multiple-entity-row.js - - - - ${nur.hassLovelaceModules.multiple-entity-row}/multiple-entity-row.js"
  ];

  # Instruct home-assistant to load these resources in the lovelace frontend
  services.home-assistant.config.lovelace = {
    resources = [
      (mkLovelaceModule "mini-graph-card") # https://github.com/kalkih/mini-graph-card
      (mkLovelaceModule "mini-media-player") # https://github.com/kalkih/mini-media-player
      (mkLovelaceModule "multiple-entity-row") # https://github.com/benct/lovelace-multiple-entity-row
    ];
  };

  services.nginx.virtualHosts."home.example.com" = {
    locations."/local/" = {
      alias = "/run/hass/";
    };
  };
}

Add custom components

In order to install a custom component, you have to place it in /var/lib/hass/custom_components. This can be achieved using systemd tmpfiles like so (for sonoff custom component):

  systemd.tmpfiles.rules = [
    "C /var/lib/hass/custom_components/sonoff - - - - ${sources.sonoff-lan}/custom_components/sonoff"
    "Z /var/lib/hass/custom_components 770 hass hass - -"
  ];

Example configurations

- Mic92's config

Misc

Run Home Assistant from GitHub repository

When developing Home Assistant for some test dependencies additional libraries are needed. A nix-shell expression for this is available here.