nixpkgs/nixos/modules/services/misc/home-assistant.nix
Martin Weinelt f41349d30d
nixos/home-assistant: Restart systemd unit on restart service
Home-assistant through its `--runner` commandline flag supports sending
exit code 100 when the `homeassistant.restart` service is called.

With `RestartForceExitStatus` we can listen for that specific exit code
and restart the whole systemd unit, providing an actual clean restart
with fresh processes. Additional treat exit code 100 as a successful
termination.
2021-05-03 00:21:25 +02:00

350 lines
13 KiB
Nix

{ config, lib, pkgs, ... }:
with lib;
let
cfg = config.services.home-assistant;
# cfg.config != null can be assumed here
configJSON = pkgs.writeText "configuration.json"
(builtins.toJSON (if cfg.applyDefaultConfig then
(recursiveUpdate defaultConfig cfg.config) else cfg.config));
configFile = pkgs.runCommand "configuration.yaml" { preferLocalBuild = true; } ''
${pkgs.remarshal}/bin/json2yaml -i ${configJSON} -o $out
# Hack to support custom yaml objects,
# i.e. secrets: https://www.home-assistant.io/docs/configuration/secrets/
sed -i -e "s/'\!\([a-z_]\+\) \(.*\)'/\!\1 \2/;s/^\!\!/\!/;" $out
'';
lovelaceConfigJSON = pkgs.writeText "ui-lovelace.json"
(builtins.toJSON cfg.lovelaceConfig);
lovelaceConfigFile = pkgs.runCommand "ui-lovelace.yaml" { preferLocalBuild = true; } ''
${pkgs.remarshal}/bin/json2yaml -i ${lovelaceConfigJSON} -o $out
'';
availableComponents = cfg.package.availableComponents;
usedPlatforms = config:
if isAttrs config then
optional (config ? platform) config.platform
++ concatMap usedPlatforms (attrValues config)
else if isList config then
concatMap usedPlatforms config
else [ ];
# Given a component "platform", looks up whether it is used in the config
# as `platform = "platform";`.
#
# For example, the component mqtt.sensor is used as follows:
# config.sensor = [ {
# platform = "mqtt";
# ...
# } ];
useComponentPlatform = component: elem component (usedPlatforms cfg.config);
# Returns whether component is used in config
useComponent = component:
hasAttrByPath (splitString "." component) cfg.config
|| useComponentPlatform component;
# List of components used in config
extraComponents = filter useComponent availableComponents;
package = if (cfg.autoExtraComponents && cfg.config != null)
then (cfg.package.override { inherit extraComponents; })
else cfg.package;
# If you are changing this, please update the description in applyDefaultConfig
defaultConfig = {
homeassistant.time_zone = config.time.timeZone;
http.server_port = cfg.port;
} // optionalAttrs (cfg.lovelaceConfig != null) {
lovelace.mode = "yaml";
};
in {
meta.maintainers = teams.home-assistant.members;
options.services.home-assistant = {
enable = mkEnableOption "Home Assistant";
configDir = mkOption {
default = "/var/lib/hass";
type = types.path;
description = "The config directory, where your <filename>configuration.yaml</filename> is located.";
};
port = mkOption {
default = 8123;
type = types.int;
description = "The port on which to listen.";
};
applyDefaultConfig = mkOption {
default = true;
type = types.bool;
description = ''
Setting this option enables a few configuration options for HA based on NixOS configuration (such as time zone) to avoid having to manually specify configuration we already have.
</para>
<para>
Currently one side effect of enabling this is that the <literal>http</literal> component will be enabled.
</para>
<para>
This only takes effect if <literal>config != null</literal> in order to ensure that a manually managed <filename>configuration.yaml</filename> is not overwritten.
'';
};
config = mkOption {
default = null;
# Migrate to new option types later: https://github.com/NixOS/nixpkgs/pull/75584
type = with lib.types; let
valueType = nullOr (oneOf [
bool
int
float
str
(lazyAttrsOf valueType)
(listOf valueType)
]) // {
description = "Yaml value";
emptyValue.value = {};
};
in valueType;
example = literalExample ''
{
homeassistant = {
name = "Home";
latitude = "!secret latitude";
longitude = "!secret longitude";
elevation = "!secret elevation";
unit_system = "metric";
time_zone = "UTC";
};
frontend = {
themes = "!include_dir_merge_named themes";
};
http = { };
feedreader.urls = [ "https://nixos.org/blogs.xml" ];
}
'';
description = ''
Your <filename>configuration.yaml</filename> as a Nix attribute set.
Beware that setting this option will delete your previous <filename>configuration.yaml</filename>.
<link xlink:href="https://www.home-assistant.io/docs/configuration/secrets/">Secrets</link>
are encoded as strings as shown in the example.
'';
};
configWritable = mkOption {
default = false;
type = types.bool;
description = ''
Whether to make <filename>configuration.yaml</filename> writable.
This only has an effect if <option>config</option> is set.
This will allow you to edit it from Home Assistant's web interface.
However, bear in mind that it will be overwritten at every start of the service.
'';
};
lovelaceConfig = mkOption {
default = null;
type = with types; nullOr attrs;
# from https://www.home-assistant.io/lovelace/yaml-mode/
example = literalExample ''
{
title = "My Awesome Home";
views = [ {
title = "Example";
cards = [ {
type = "markdown";
title = "Lovelace";
content = "Welcome to your **Lovelace UI**.";
} ];
} ];
}
'';
description = ''
Your <filename>ui-lovelace.yaml</filename> as a Nix attribute set.
Setting this option will automatically add
<literal>lovelace.mode = "yaml";</literal> to your <option>config</option>.
Beware that setting this option will delete your previous <filename>ui-lovelace.yaml</filename>
'';
};
lovelaceConfigWritable = mkOption {
default = false;
type = types.bool;
description = ''
Whether to make <filename>ui-lovelace.yaml</filename> writable.
This only has an effect if <option>lovelaceConfig</option> is set.
This will allow you to edit it from Home Assistant's web interface.
However, bear in mind that it will be overwritten at every start of the service.
'';
};
package = mkOption {
default = pkgs.home-assistant.overrideAttrs (oldAttrs: {
doInstallCheck = false;
});
defaultText = literalExample ''
pkgs.home-assistant.overrideAttrs (oldAttrs: {
doInstallCheck = false;
})
'';
type = types.package;
example = literalExample ''
pkgs.home-assistant.override {
extraPackages = ps: with ps; [ colorlog ];
}
'';
description = ''
Home Assistant package to use. By default the tests are disabled, as they take a considerable amout of time to complete.
Override <literal>extraPackages</literal> or <literal>extraComponents</literal> in order to add additional dependencies.
If you specify <option>config</option> and do not set <option>autoExtraComponents</option>
to <literal>false</literal>, overriding <literal>extraComponents</literal> will have no effect.
Avoid <literal>home-assistant.overridePythonAttrs</literal> if you use <literal>autoExtraComponents</literal>.
'';
};
autoExtraComponents = mkOption {
default = true;
type = types.bool;
description = ''
If set to <literal>true</literal>, the components used in <literal>config</literal>
are set as the specified package's <literal>extraComponents</literal>.
This in turn adds all packaged dependencies to the derivation.
You might still see import errors in your log.
In this case, you will need to package the necessary dependencies yourself
or ask for someone else to package them.
If a dependency is packaged but not automatically added to this list,
you might need to specify it in <literal>extraPackages</literal>.
'';
};
openFirewall = mkOption {
default = false;
type = types.bool;
description = "Whether to open the firewall for the specified port.";
};
};
config = mkIf cfg.enable {
networking.firewall.allowedTCPPorts = mkIf cfg.openFirewall [ cfg.port ];
systemd.services.home-assistant = {
description = "Home Assistant";
after = [ "network.target" ];
preStart = optionalString (cfg.config != null) (if cfg.configWritable then ''
cp --no-preserve=mode ${configFile} "${cfg.configDir}/configuration.yaml"
'' else ''
rm -f "${cfg.configDir}/configuration.yaml"
ln -s ${configFile} "${cfg.configDir}/configuration.yaml"
'') + optionalString (cfg.lovelaceConfig != null) (if cfg.lovelaceConfigWritable then ''
cp --no-preserve=mode ${lovelaceConfigFile} "${cfg.configDir}/ui-lovelace.yaml"
'' else ''
rm -f "${cfg.configDir}/ui-lovelace.yaml"
ln -s ${lovelaceConfigFile} "${cfg.configDir}/ui-lovelace.yaml"
'');
serviceConfig = let
# List of capabilities to equip home-assistant with, depending on configured components
capabilities = [
# Empty string first, so we will never accidentally have an empty capability bounding set
# https://github.com/NixOS/nixpkgs/issues/120617#issuecomment-830685115
""
] ++ (unique (optionals (useComponent "bluetooth_tracker" || useComponent "bluetooth_le_tracker") [
# Required for interaction with hci devices and bluetooth sockets
# https://www.home-assistant.io/integrations/bluetooth_le_tracker/#rootless-setup-on-core-installs
"CAP_NET_ADMIN"
"CAP_NET_RAW"
] ++ lib.optionals (useComponent "emulated_hue") [
# Alexa looks for the service on port 80
# https://www.home-assistant.io/integrations/emulated_hue
"CAP_NET_BIND_SERVICE"
] ++ lib.optionals (useComponent "nmap_tracker") [
# https://www.home-assistant.io/integrations/nmap_tracker#linux-capabilities
"CAP_NET_ADMIN"
"CAP_NET_BIND_SERVICE"
"CAP_NET_RAW"
]));
in {
ExecStart = "${package}/bin/hass --runner --config '${cfg.configDir}'";
ExecReload = "${pkgs.coreutils}/bin/kill -HUP $MAINPID";
User = "hass";
Group = "hass";
Restart = "on-failure";
RestartForceExitStatus = "100";
SuccessExitStatus = "100";
KillSignal = "SIGINT";
# Hardening
AmbientCapabilities = capabilities;
CapabilityBoundingSet = capabilities;
DeviceAllow = [
"char-ttyACM rw"
"char-ttyAMA rw"
"char-ttyUSB rw"
];
DevicePolicy = "closed";
LockPersonality = true;
MemoryDenyWriteExecute = true;
NoNewPrivileges = true;
PrivateTmp = true;
PrivateUsers = false; # prevents gaining capabilities in the host namespace
ProtectClock = true;
ProtectControlGroups = true;
ProtectHome = true;
ProtectHostname = true;
ProtectKernelLogs = true;
ProtectKernelModules = true;
ProtectKernelTunables = true;
ProtectProc = "invisible";
ProcSubset = "pid";
ProtectSystem = "strict";
RemoveIPC = true;
ReadWritePaths = let
# Allow rw access to explicitly configured paths
cfgPath = [ "config" "homeassistant" "allowlist_external_dirs" ];
value = attrByPath cfgPath [] cfg;
allowPaths = if isList value then value else singleton value;
in [ "${cfg.configDir}" ] ++ allowPaths;
RestrictAddressFamilies = [
"AF_UNIX"
"AF_INET"
"AF_INET6"
] ++ optionals (useComponent "bluetooth_tracker" || useComponent "bluetooth_le_tracker") [
"AF_BLUETOOTH"
];
RestrictNamespaces = true;
RestrictRealtime = true;
RestrictSUIDSGID = true;
SupplementaryGroups = [ "dialout" ];
SystemCallArchitectures = "native";
SystemCallFilter = [
"@system-service"
"~@privileged"
];
UMask = "0077";
};
path = [
"/run/wrappers" # needed for ping
];
};
systemd.targets.home-assistant = rec {
description = "Home Assistant";
wantedBy = [ "multi-user.target" ];
wants = [ "home-assistant.service" ];
after = wants;
};
users.users.hass = {
home = cfg.configDir;
createHome = true;
group = "hass";
uid = config.ids.uids.hass;
};
users.groups.hass.gid = config.ids.gids.hass;
};
}