Azure Event Hub


The Azure Event Hub integration allows you to hook into the Home Assistant event bus and send events to Azure Event Hub or to a Azure IoT Hub.

First time setup

This assumes you already have a Azure account. Otherwise create a Free account here.

You need to create a Event Hub namespace and a Event Hub in that namespace, you can follow this guide. Alternatively you can directly deploy an ARM template with the namespace and the Event Hub from here.

You must then create a Shared Access Policy for the Event Hub with ‘Send’ claims or use the RootManageAccessKey from your namespace (this key has additional claims, including managing the event hub and listening, which are not needed for this purpose), for more details on the security of Event Hubs go here.

Once you have the name of your namespace, instance, Shared Access Policy and the key for that policy, you can setup the integration itself.

The alternative approach is to use a connection string, this can be retrieved in the same way as the Shared Access Policy and this can also be gotten for a device in an IoT Hub (Event Hub-compatible connection string).

The final thing to consider is how often you want the integration to send messages in a batch to your hub, this is set with the send_interval, with a default of 5 seconds. The other thing to look at is what the maximum delay you want to use, since this component runs in a asynchronous way there is no guarantee that the sending happens exactly on time, so depending on your semantics you might want messages discarded. The actual check of the time happens with max_delay plus send_interval, so that even with a long send_interval the semantics are the same.

Configuration

Add the following lines to your configuration.yaml file:

# Example configuration.yaml entry
azure_event_hub:
  event_hub_namespace: NAMESPACE_NAME
  event_hub_instance_name: EVENT_HUB_INSTANCE_NAME
  event_hub_sas_policy: SAS_POLICY_NAME
  event_hub_sas_key: SAS_KEY
  filter:
    include_domains:
    - homeassistant
    - light
    - media_player

Configuration Variables

event_hub_namespacestring(Exclusive)

The name of your Event Hub namespace.

event_hub_instance_namestring(Exclusive)

The name of your Event Hub instance.

event_hub_sas_policystring(Exclusive)

The name of your Shared Access Policy.

event_hub_sas_keystring(Exclusive)

The key for the Shared Access Policy.

event_hub_connection_stringstring(Exclusive)

The connection string to your event hub.

send_intervalinteger(Optional, default: 5)

The interval in seconds should events be sent to the Event Hub.

max_delayinteger(Optional, default: 30)

The time in seconds after which a message is to be discarded.

filtermapRequired

Filter domains and entities for Event Hub. (Configure Filter)

Default:

Includes all entities from all domains

include_domainslist(Optional)

List of domains to include (e.g., light).

exclude_domainslist(Optional)

List of domains to exclude (e.g., light).

include_entity_globslist(Optional)

Include all entities matching a listed pattern (e.g., sensor.weather_*).

exclude_entity_globslist(Optional)

Exclude all entities matching a listed pattern (e.g., sensor.weather_*).

include_entitieslist(Optional)

List of entities to include (e.g., light.attic).

exclude_entitieslist(Optional)

List of entities to include (e.g., light.attic).

Not filtering domains or entities will send every event to Azure Event Hub, thus taking up a lot of space.
Event Hubs have a retention time of at most 7 days, if you do not capture or use the events they are deleted automatically from the Event Hub, the default retention is 1 day.

Configure Filter

By default, no entity will be excluded. To limit which entities are being exposed to Azure Event Hub, you can use the filter parameter.

# Example filter to include specified domains and exclude specified entities
azure_event_hub:
  event_hub_namespace: NAMESPACE_NAME
  event_hub_instance_name: EVENT_HUB_INSTANCE_NAME
  event_hub_sas_policy: SAS_POLICY_NAME
  event_hub_sas_key: SAS_KEY
  filter:
    include_domains:
      - alarm_control_panel
      - light
    include_entity_globs:
      - binary_sensor.*_occupancy
    exclude_entities:
      - light.kitchen_light

Filters are applied as follows:

  1. No includes or excludes - pass all entities
  2. Includes, no excludes - only include specified entities
  3. Excludes, no includes - only exclude specified entities
  4. Both includes and excludes:
    • Include domain and/or glob patterns specified
      • If domain is included, and entity not excluded or match exclude glob pattern, pass
      • If entity matches include glob pattern, and entity does not match any exclude criteria (domain, glob pattern or listed), pass
      • If domain is not included, glob pattern does not match, and entity not included, fail
    • Exclude domain and/or glob patterns specified and include does not list domains or glob patterns
      • If domain is excluded and entity not included, fail
      • If entity matches exclude glob pattern and entity not included, fail
      • If entity does not match any exclude criteria (domain, glob pattern or listed), pass
    • Neither include or exclude specifies domains or glob patterns
      • If entity is included, pass (as #2 above)
      • If entity include and exclude, the entity exclude is ignored

Advanced configuration

This is what the configuration will look like when using a connection string directly, instead of the four parameters. It also shows how to set the send_interval and max_delay to something other than the default. This means once every minute the integration will connect to your hub and send messages, but the messages have to be less than 65 seconds old at the time of sending for them to be counted (send_interval + max_delay).

# Connection string config with non-defaults for send_interval and max_delay
azure_event_hub:
  event_hub_connection_string: CONNECTION_STRING
  send_interval: 60
  max_delay: 5

Using the data in Azure

There are a number of ways to stream the data that comes into the Event Hub into storages in Azure, the easiest way is to use the built-in Capture function and this allows you to capture the data in Azure Blob Storage or Azure Data Lake store, details here.

Other storages in Azure (and outside) are possible with a Azure Stream Analytics job, for instance for Cosmos DB, Azure SQL DB, Azure Table Storage, custom writing to Azure Blob Storage and Topic and Queues.

On the analytical side, Event Hub can be directly fed into Azure Databricks Spark, Azure Time Series Insights and Microsoft Power BI.

The final way to use the data in Azure is to connect a Azure Function to the Event Hub using the Event Hub trigger binding.