Creating a trigger that transmits messages to a Cloud Functions function from an Yandex IoT Core registry or device topic
Create a trigger for a Yandex IoT Core device or registry topic and process message copies using the Yandex Cloud Functions function.
Warning
The trigger must be in the same cloud as the registry or device whose topic it reads messages from.
Getting started
To create a trigger, you need:
-
A function that the trigger will invoke. If you do not have a function:
-
(Optional) A Dead Letter Queue where messages that could not be processed by a function will be redirected. If you do not have a queue, create one.
-
Service accounts with rights to invoke the function and (optionally) write messages to the Dead Letter Queue. You can use the same service account or different ones. If you do not have a service account, create one.
- Registry or device from whose topics the trigger will receive message copies. If you have neither:
Creating a trigger
Note
The trigger is initiated within 5 minutes of being created.
-
In the management console
, select the folder where you want to create a trigger. -
Select Cloud Functions.
-
In the left-hand panel, select
-
Click Create trigger.
-
Under Basic settings:
- Enter a name and description for the trigger.
- In the Type field, select
IoT Core (device)
. - In the Launched resource field, select
Function
.
-
Under IoT Core message settings, specify the registry, device, and MQTT topic to create a trigger for. When creating a trigger for a registry topic, you do not need to specify a device or an MQTT topic. If no MQTT topic is set, the trigger fires for all registry or device topics.
-
Under Function settings, select a function and specify:
- Function version tag.
- Service account to invoke the function under.
-
(Optional) Under Repeat request settings:
- In the Interval field, specify the time after which the function will be invoked again if the current attempt fails. The values may range from 10 to 60 seconds. The default value is 10 seconds.
- In the Number of attempts field, specify the number of invocation retries before the trigger moves a message to the Dead Letter Queue. The values may range from 1 to 5. The default value is 1.
-
(Optional) Under Dead Letter Queue settings, select the dead letter queue and the service account with write permissions for this queue.
-
Click Create trigger.
If you do not have the Yandex Cloud command line interface yet, install and initialize it.
The folder specified in the CLI profile is used by default. You can specify a different folder using the --folder-name
or --folder-id
parameter.
To create a trigger that invokes a function, run this command:
yc serverless trigger create internet-of-things \
--name <trigger_name> \
--registry-id <registry_ID> \
--device-id <device_ID> \
--mqtt-topic '$devices/<device_ID>/events' \
--batch-size <message_batch_size> \
--batch-cutoff <maximum_wait_time> \
--invoke-function-id <function_ID> \
--invoke-function-service-account-id <service_account_ID> \
--retry-attempts 1 \
--retry-interval 10s \
--dlq-queue-id <dead_letter_queue_ID> \
--dlq-service-account-id <service_account_ID>
Where:
--name
: Trigger name.--registry-id
: Registry ID.--device-id
: Device ID. If you are creating a trigger for a registry topic, you can omit this parameter.--mqtt-topic
: MQTT topic you want to create a trigger for. This is an optional parameter. If this parameter is skipped, the trigger fires for all registry or device topics.
--batch-size
: Size of the message batch from MQTT topics. This is an optional parameter. The values may range from 1 to 10. The default value is 1.--batch-cutoff
: Maximum waiting time. This is an optional parameter. The values may range from 1 to 60 seconds. The default value is 1 second. The trigger groups messages for a period not exceedingbatch-cutoff
and sends them to a function. The number of messages cannot exceedbatch-size
.
--invoke-function-id
: Function ID.--invoke-function-service-account-id
: Service account with rights to invoke the function.--retry-attempts
: Number of invocation retries before the trigger moves a message to the Dead Letter Queue. Optional parameter. The values may range from 1 to 5. The default value is 1.--retry-interval
: Time after which the function will be invoked again if the current attempt fails. Optional parameter. The values may range from 10 to 60 seconds. The default value is 10 seconds.--dlq-queue-id
: Dead Letter Queue ID. Optional parameter.--dlq-service-account-id
: Service account with the permission to write messages to the Dead Letter Queue. Optional parameter.
Result:
id: a1sl0mkmimfj********
folder_id: b1g88tflru0e********
created_at: "2019-09-25T13:54:35.654935Z"
name: iot-trigger
rule:
iot_message:
registry_id: arenou2oj4ct********
device_id: areqjd6un3af********
mqtt_topic: $devices/areqjd6un3af********/events
batch_settings:
size: "1"
cutoff: 0s
invoke_function:
function_id: d4eofc7n0m03********
function_tag: $latest
service_account_id: aje3932acd0c********
retry_settings:
retry_attempts: "1"
interval: 10s
status: ACTIVE
Terraform
For more information about the provider resources, see the documentation on the Terraform
If you change the configuration files, Terraform automatically detects which part of your configuration is already deployed, and what should be added or removed.
If you don't have Terraform, install it and configure the Yandex Cloud provider.
To create a trigger for Yandex IoT Core:
-
In the configuration file, describe the trigger parameters.
Here is an example of the configuration file structure:
resource "yandex_function_trigger" "my_trigger" { name = "<trigger_name>" description = "<trigger_description>" iot { registry_id = "<registry_ID>" device_id = "<device_ID>" topic = "<topic_ID>" batch_cutoff = 10 batch_size = 1 } function { id = "<function_ID>" service_account_id = "<service_account_ID>" } }
Where:
-
name
: Trigger name. The name format is as follows:- The name must be from 3 to 63 characters long.
- It may contain lowercase Latin letters, numbers, and hyphens.
- The first character must be a letter and the last character cannot be a hyphen.
-
description
: Trigger description. -
iot
: Topic parameters:registry-id
: Registry ID.device-id
: Device ID. If you are creating a trigger for a registry topic, you can omit this parameter.topic
: ID of the topic you want to create a trigger for. If no topic is set, the trigger fires for all registry or device topics.
-
function
: Settings for the function, which will be activated by the trigger:id
: Function ID.service_account_id
: ID of the service account with permissions to invoke the function.
-
batch_cutoff
: Maximum wait time. Acceptable values are from 1 to 60 seconds. The trigger groups messages for a period of time not exceeding the specified timeout and sends them to a container. At the same time, the number of messages does not exceed the specifiedbatch-size
group. -
batch_size
: Message batch size. Acceptable values are from 1 to 10.
For more information about resource parameters in Terraform, see the provider documentation
. -
-
Make sure the configuration files are valid.
-
In the command line, go to the directory where you created the configuration file.
-
Run a check using this command:
terraform plan
If the configuration is described correctly, the terminal will display a list of created resources and their parameters. If the configuration contains any errors, Terraform will point them out.
-
-
Deploy cloud resources.
-
If the configuration does not contain any errors, run this command:
terraform apply
-
Confirm creating the resources: type
yes
in the terminal and press Enter.All the resources you need will then be created in the specified folder. You can check the new resources and their configuration using the management console
or this CLI command:yc serverless trigger get <trigger_ID>
-
To create a trigger for Yandex IoT Core, use the create REST API method for the Trigger resource or the TriggerService/Create gRPC API call.
Checking the result
Check that the trigger operates correctly. Do it by viewing function logs that present information on invocations.