Data_template, divide into variables

Configuration
1

Hi!
I am trying to implement a automation script that allow me to more or less call all hass services from MQTT without needing to design an automation for each service.

My first try was this:

- alias: 'MQTT service'
  trigger:
    platform: mqtt
    topic: "ha/service/+"
  action:
    service_template: "{{ trigger.topic.split('/')[-1] }}"
    data_template:
      entity_id: "{{ trigger.payload }}"

That makes it possible for example to light a hass connected light by sending a mqtt message with

topic: "ha/service/light.turn_on
payload: “light.mylight”

But that is quite limited to only sending entity_id:s. I would like to do the same by sending a Json instead like:

topic: "ha/service/light.turn_on
payload: “{ entity_id: light.mylight, brightness: 48 }”

Tried different things but always fails, anyone with ideas?

2

No one with ideas?

failed attempts that I have tried:

data_template: "{{ trigger.payload_json }}"

data_template:
      variables: "{{ trigger.payload_json }}"