Improving the LIFX Day & Dusk functionality

My docker-lifx-daydusk project attempts to solve two usability concerns with the Day & Dusk functionality built-into the LIFX app: it does not require a connection to the LIFX Cloud and it provides more configurable options for each scheduled transition event.

Supported Platforms

The lifx-daydusk image is supported on the following platforms:

• amd64: 64-bit Intel or AMD processors including Intel-based Synology or QNAP NAS devices.
• arm64v8: 64-bit Arm processors including Raspberry Pi 3 Model B/B+ and Raspberry Pi 4.

Docker will automatically download the correct image based on the archiecture upon which it is running.

Usage

LIFX discovery requires UDP broadcast access to your local network in order to successfully discover bulbs. This can be achieved using the --net=host flag. Currently this image will not work if you are using Docker for Mac or Docker for Windows.

The following command will start the container with the required configuration:

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docker run \
  --detach \
  --name=daydusk \
  --net=host \
  -e PUID=<UID> \
  -e PGID=<GID> \
  -e TZ=<Time Zone> \
  -v /path/to/config/:/config/ \
  djelibeybi/lifx-daydusk:develop

Parameters

The following parameters can be specified on the command-line when executing docker run to start the container:

• --net=host: Shares host networking with container¹. (required)
• -e TZ: for timezone information e.g. -e TZ=Europe/London (required)
• -v /path/to/config/:/config/ - Required: see below for details.
• -e PGID: for GroupID - see below for explanation
• -e PUID: for UserID - see below for explanation

IMPORTANT: You must set a valid TZ value otherwise the container timezone will be set to UTC and your events may fire at the wrong time.

Creating the daydusk.yml configuration file

The sample docker run command above maps the local /path/to/config directory to the /config directory inside the container. You should change /path/to/config to an actual directory on your host system and you must create at least the daydusk.yml file in this directory.

NOTE: the sample-daydusk.yml matches the default LIFX Day & Dusk configuration exactly including powering on the specified bulbs at the start of each event.

Syntax

The daydusk.yml file consists of one or more named events that define the time to start the transition, the end state of the bulbs, the duration of the transition and whether the bulbs should turn on automatically before the transition starts or turn off automatically after the transition ends.

In the example below, the event named wakeup will fire at 6:30am on Saturday and Sunday to trigger the bulbs to power on in whatever state they were in when they were previously powered off and then begin a 30 minute transition to 80% brightness at 4000 kelvin:

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daydusk:
  schedules:
    wakeup:
      days:
        - SATURDAY
        - SUNDAY
      hour: 6
      minute: 30
      brightness: 0.8
      kelvin: 4000
      duration: 1800
      power: ON

Multiple events can be included within the file, using the following syntax:

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daydusk:
  schedules:
     wakeup:
     ...

     day:
     ...

     evening:
     ...

     nighttime:
     ...

Note the opening daydusk: and schedules: only appear once at the beginning of the file. You can validate your YAML syntax online at http://www.yamllint.com/.

There is no limit to the number of events, though each event will add additional time to process when the container starts. To change the events, use docker stop to shut down the running container, modify the daydusk.yml file and then run docker start to start the container back up again.

The following table documents each parameter and all parameters are required for each event:

The sample-daydusk.yml file contains four events that replicate the default LIFX Day & Dusk times, brightness and kelvin values as well as the transition duration and power state changes.

Specifying bulbs for each event

The reference field is used to determine which bulbs will be targeted for each event. If an event does not contain a reference field, all discovered bulbs will be used. The reference field can be specified in any of the following formats on a per-event basis, i.e. you can chose to use one method for an event and a different method for another.

Currently, no validation is performed to ensure the serial numbers are valid or if any specified files exist. Likewise, no validation of the provided filters is performed, so it’s possible for a filter to return no results or unexpected results if misconfigured.

The available formats are:

A single serial number:

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reference: d073d5000001

A list of serial numbers:

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reference:
  - d073d5000001
  - d073d5000002

A file that contains a list of serial numbers (one per line):

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reference: file:/config/bulbs.conf

A filter² that is dynamically evaluated on each run based on bulb-specific data:

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reference: match:group_name=bedroom

The Photons Core documentation maintains a list valid filters that can be used with this option. Multiple filters can be combined using an ampersand, e.g. match:group_name=bedroom&power=on would match all bulbs in the group named bedroom that are currently powered on.

Using the PUID and PGID environment variables

Mounting volumes by using the -v parameter in the docker run command can cause permissions issues between the host and the container.

To avoid this issue, determine the uid and gid of the user that owns the /path/to/config directory on the host and provide those values via the PUID and PGID environment variables available for the docker run command.

You can use the following command on the host system to determine the correct PUID and PGID values, taking care to replace /path/to/config with the actual directory path on the host:

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$ ls -ldn /path/to/config | awk '{print "PUID="$3" and PGID="$4}'
PUID=501 and PGID=20

Alternatively, use the id command to get the appropriate uid and gid values for a specific user:

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$ id username
uid=501(username) gid=20(staff) groups=20(staff)

Acknowledgements

• oznu for docker-homebridge upon which the multi-arch support for this repo and image is slightly mostly derived.
• delfick for photons-core upon which my code depends and for providing additional pointers on using Photons for configuration validation.