Plate Handler

Links Plate Recognizer's Stream API to Home Assistant.

• Receive notifications when plates are spotted.
• Associate names with plates.
• Automatic logbook entries and events for spotted plates.

Setup

If you're using Docker Compose, set up plate-handler as a service:

version: 3.1
services:
  plate-handler:
    container_name: plate-handler
    image: adamjernst/plate-handler:latest
    restart: unless-stopped
    # plate-handler connects to Home Assistant on port 8123;
    # plate-recognizer connects to plate-handler via webhook
    # on port 8402. Host networking is the simplest way to
    # allow this, but custom networks would be more secure.
    network_mode: "host"
    volumes:
      - /var/plate-handler:/data
      - /PATH_TO_HOME_ASSISTANT_CONFIG/www/plates:/plates
    environment:
      ACCESS_TOKEN: "generate-in-home-assistant"
      NOTIFY_DEVICE: mobile_app_bobs_iphone
      PLATES_URL: "https://yoursite.ui.nabu.casa/local/plates/"

Generate the ACCESS_TOKEN value using the Long-Lived Access Tokens section at the bottom of your Home Assistant Profile page.

NOTIFY_DEVICE should be set to mobile_app_ followed by the name of your mobile device, as described in the Home Assistant documentation:

[Your device name is found] in the App Configuration menu of the [Home Assistant app] sidebar and defaults to the name specified in the General>About within the iOS Settings app or under About>Phone in Android settings (with spaces and non-alphanumeric characters replaced by underscores).

For example, if your iPhone is called "Bob's iPhone", NOTIFY_DEVICE should be set to mobile_app_bobs_iphone.

PLATES_URL is optional. If set, it must point to a publicly accessible URL that contains images of plates. See "Images" below.

HOST can optionally be set to the hostname and port used to connect to the Home Assistant API. If unset, it defaults to localhost:8123.

Configuring Plate Recognizer Stream

You must use the webhook_target setting in Plate Recognizer Stream's config.ini file. By default the webhook listens on port 8402 at the path /webhook/. An example configuration:

[cameras]
  [[camera-1]]
    active = yes
    url = rtsp://user:pass@192.168.1.2:554/
    name = LPR

    webhook_target = http://localhost:8402/webhook/
    webhook_image = yes
    webhook_image_type = original

Volumes

/data is used to store a SQLite database with names for plates and the times those plates were spotted. This can be mapped to any path on the host machine. The example Compose configuration above shows a bind mount to /var/plate-handler.

/plates is used to store images of plates, if the PLATES_URL environment variable is set. See "Images" below.

Images

Home Assistant has support for hosting files, which can be used to include an image of the license plate with notifications. To enable image notifications:

Create a www/plates subdirectory in your Home Assistant config directory. For example:

# mkdir -p /PATH_TO_HOME_ASSISTANT_CONFIG/www/plates

Map /plates to the www/plates directory. This is already done in the sample Docker Compose configuration above; you just need to substitute the correct path to your configuration directory:

...
    volumes:
      - /PATH_TO_HOME_ASSISTANT_CONFIG/www/plates:/plates

Set the PLATES_URL environment variable to a publicly accessible URL representing the plates directory. This is also already done in the sample Docker Compose configuration above, but you must substitute the URL for your site. Assuming you use Home Assistant Cloud, the URL will look something like this:

    environment:
      PLATES_URL: "https://yoursite.ui.nabu.casa/local/plates/"

Device Groups

To send notifications to more than one device, create a notification group.

For example, add the following to your Home Assistant configuration.yaml file to create a group called ALL_DEVICES:

notify:
  - name: ALL_DEVICES
    platform: group
    services:
      - service: mobile_app_bobs_iphone
      - service: mobile_app_lindas_iphone

After editing configuration.yaml, restart Home Assistant via Configuration → Server Controls → Restart.

Set the NOTIFY_DEVICE environment variable to the name of your group, e.g. ALL_DEVICES.

Potential Future Improvements

• Create a Home Assistant Add-on to streamline setup.
• Android notification support.
• Better logbook entries.
• MMC (Make, Model, Color) support.
• Allow muting notifications for a particular plate.