openhab-pythonrule-engine

OpenHAB python rule engine

A Python 3.x rule engine for OpenHAB. This rule engine allows you to define rules using Python 3.x.

Please note that OpenHAB username/password authentication (basic authentication) must be activated. To do so, open API security settings and enable the advanced setting Allow Basic Authentication.

To run this software, you can use Docker or the PIP package manager, as shown below

Docker approach

sudo docker run -e openhab_uri=http://192.168.1.17:8080 -e user=me -e pwd=secret -v /etc/openhab2/automation/rules/python:/rules grro/pythonrule_engine 

PIP approach

sudo pip install openhab-pythonrule-engine

sudo pyrule --command listen --openhab_uri http://localhost:8080 --python_rule_directory /etc/openhab2/automation/rules/python --user me --pwd secret

In this case, the rules engine connects to the Openhab instance running on the local machine on port 8080. Also, the /etc/openhab2/automation/rules/python directory is used to search for python-based rules

If you are using a systemd-based Linux distribution, you can use the register command to register and start the rule engine as a systemd entity. This automatically starts the rule engine at boot time. Starting the Rule Engine manually with the listen command is no longer necessary.

sudo pyrule --command register --openhab_uri http://localhost:8080 --python_rule_directory /etc/openhab2/automation/rules/python --user me --pwd secret

Rules

To trigger a rule method, the @when decorator must be used. Currently the conditions listed below are supported

condition	example	description
cron	@when('Time cron */1 * * * *')	fires based on cron expression
item state change	@when('Item PhoneLisaLastSeen changed')	fires when the specified Item's State changes
item command	@when('Item SelectDoorCam received command ON') @when('Item SelectDoorCam received command OFF')	fires when the specified Item receives a Command

Example: my_rule.py (located within /etc/openhab2/automation/rules/python)

from openhab_pythonrule_engine.condition import when
from openhab_pythonrule_engine.item_registry import ItemRegistry


@when("Time cron */1 * * * *") # each minute
@when("Item PhoneLisaLastSeen changed")
@when("Item PhoneTimLastSeen changed")
def update_presence_based_on_phone_seen(item_registry: ItemRegistry):
    last_time_present = item_registry.get_state_as_datetime('LastDateTimePresence')
    for phone_name in item_registry.get_group_membernames('Phones'):
        last_seen = item_registry.get_state_as_datetime(phone_name)
        print(last_seen)
        if last_seen > last_time_present:
            last_time_present = last_seen
    item_registry.set_state('LastDateTimePresence', last_time_present)

# uncomment the code below for local debugging
#item_registry = ItemRegistry.new_singleton(openhab_uri="http://192.168.1.27:8080/", user="xxx", pwd="secret")
#update_presence_based_on_phone_seen(item_registry)

If the rule method defines a (single!) argument, the item_registry object is automatically injected. The item_registry object provides methods for getting and setting the item state. When setting the state, the data value is automatically converted to the item-specific data type