Supported Event Sources

This section describes the cloud services that can be configured as event sources for your FunctionGraph functions. After you preconfigure the event source mapping, these event sources automatically invoke the relevant function when detecting events.

SMN

Simple Message Notification (SMN) sends messages to email addresses, mobile phones, or HTTP/HTTPS URLs. If you create a function with an SMN trigger, messages published to a specified topic will be passed as a parameter (SMN example event) to invoke the function. Then, the function processes the event, for example, publishing messages to other SMN topics or sending them to other cloud services. For details, see section "Using an SMN Trigger" in the FunctionGraph User Guide.

API Gateway

API Gateway is an API hosting service that helps enterprises to build, manage, and deploy APIs at any scale. With API Gateway, your function can be invoked through HTTPS by using a custom REST API and a specified backend. You can map each API operation (such as, GET and PUT) to a specific function. API Gateway invokes the relevant function when an HTTPS request (API Gateway example event) is sent to the API backend. For details, see section "Using an APIG Trigger" in the FunctionGraph User Guide.

OBS

Object Storage Service (OBS) is a stable, secure, efficient, and easy-to-use cloud storage service. You can create a function to process OBS bucket events, for example, creating and deleting objects. When an image is uploaded to a specified bucket, OBS invokes the function to read the image and create a thumbnail. For details, see section "Using an OBS Trigger" in the FunctionGraph User Guide.

**Table 1** Event types supported by OBS
Event	Description
ObjectCreated	All kinds of object creation operations, including PUT, POST, and COPY of objects, as well as the merging of parts.
Put	Use the PUT method to upload objects.
Post	Use the POST method to upload objects.
Copy	Use the COPY method to replicate objects.
CompleteMultipartUpload	Merge parts of multi-part tasks.
ObjectRemoved	Delete objects.
Delete	Delete objects by versions.
DeleteMarkerCreated	Delete objects without specifying versions.

Multiple event types can be used on the same object. For example, if you have selected Put, Copy, and Delete in an event notification rule, a notification message will be sent to you when the specified object is uploaded to, copied to, or deleted from the bucket. ObjectCreated contains Put, Post, Copy, and CompleteMultipartUpload. If you select ObjectCreated, the others are automatically selected and cannot be selected again. Similarly, if you select ObjectRemoved, Delete and DeleteMarkerCreated are automatically selected and cannot be selected again.

Timer

You can schedule a timer (timer example event) to invoke your code based on a fixed rate of minutes, hours, or days or a cron expression. For details, see section "Using a Timer Trigger" in the FunctionGraph User Guide.

LTS

Log Tank Service (LTS) collects and stores logs, allowing you to query them in real time. If you create a function with an LTS trigger, subscribed logs collected by LTS will be passed as a parameter (LTS example event) to invoke the function. Then, the function processes or analyzes the logs, or loads the logs to other systems. For details, see section "Using an LTS Trigger" in the FunctionGraph User Guide.

CTS

Cloud Trace Service (CTS) collects operation records of subscribed cloud resources. If you create a function with a CTS trigger, collected operation records of specified cloud services will be passed as a parameter (CTS example event) to invoke the function. Then, the function analyzes and processes key information in the operation records, automatically recovers system or network modules, or reports alarms to service personnel by SMS or email. For details, see section "Using a CTS Trigger" in the FunctionGraph User Guide.

DMS for Kafka

DMS for Kafka is a message queuing service that provides Kafka premium instances. If you create a Kafka trigger for a function, when a message is sent to a Kafka instance topic, FunctionGraph will retrieve the message and trigger the function to perform other operations. For details, see section "Using a Kafka Trigger" in the FunctionGraph User Guide.

Cloud Eye

Cloud Eye is a multi-dimensional resource monitoring platform. FunctionGraph is interconnected with Cloud Eye to report metrics, allowing you to view function metrics and alarm messages through Cloud Eye. For more information about metrics, see section "Viewing Function Metrics" in the FunctionGraph User Guide.

DMS for RabbitMQ

When a DMS (for RabbitMQ) trigger is used, FunctionGraph periodically polls for new messages in a specific topic bound to the exchange of a RabbitMQ instance and passes the messages as input parameters to invoke functions.

Example Events

SMN example event

In the following example, the function name is test and the topic name is serverless_Test. subject is the message header, and message is the message body.

{
    "record": [{
        "event_version": "1.0",
        "smn": {
            "message_attributes": null,
            "subject": "This is the message title of smn trigger",
            "message_id": "a5dbd701d70d4ac2a153e7dd6dd9b601",
            "topic_urn": "urn:smn:xx-xxxxx-x:bb8695913bb74682b9ca82a8803b60d8:serverless_Test",
            "type": "notification",
            "message": "This is the message body of smn trigger",
            "timestamp": "2017-11-15T04:02:24Z"
            },
        "event_source": "smn",
        "event_subscription_urn": "urn:fss:xx-xxxxx-xxx:bb8695913bb74682b9ca82a8803b60d8:function:default:obsTrigger-Test1:latest"
    }],
    "functionname": "test",
    "requestId": "7c307f6a-cf68-4e65-8be0-4c77405a1b2c",
    "timestamp": "Wed Nov 15 2017 12:00:00 GMT+0800 (CST)"
}

API Gateway example event

When a function is invoked due to an API Gateway event, the request body is encrypted by default.

{
    "httpMethod": "GET",     //Request method
    "path": "/test/hello",   //Request path
    "pathParameters": {      //Path parameters
        "proxy": "hello"
    },
    "queryStringParameters": { //Query parameters
        "name": "me"
    },
    "headers": {               //Request header
        "x-stage": "RELEASE",
        "Host": "3f96e175-d5e4-4d4b-ae7e-f6d264e63b23-apigw.xx-xxx-x.xxx.com",
        "User-Agent": "lua-resty-http/0.10 (Lua) ngx_lua/10008",
        ...
    },
    "body": "...",              //Request body
    "isBase64Encoded":false/true,  //Indicates whether the request body is encoded using Base64.
    "requestContext": {
        "stage": "test",          //Environment name
        "requestId": "dd4337362c02c7d77299e78781beb4b1",
        "apiId": "41b45ea3-70b5-11e6-b7bd-69b5aaebc7d9"
    },
}

The function returns characters strings by using the following structure.

{
    "isBase64Encoded": true|false,
    "statusCode": httpStatusCode,
    "headers": {"headerName":"headerValue",...},
    "body": "..."
}

DIS example event

In the following example, the stream name is dis-swtest. This example shows the format of a request received by a function associated with the DIS trigger.

{
    "ShardID": "shardId-0000000000",
    "Message": {
        "next_partition_cursor": "eyJnZXRJdGVyYXRvclBhcmFtIjp7InN0cmVhbS1uYW1lIjoiZGlzLXN3dGVzdCIsInBhcnRpdGlvbi1pZCI6InNoYXJkSWQtMDAwMDAwMDAwMCIsImN1cnNvci10eXBlIjoiVFJJTV9IT1JJWk9OIiwic3RhcnRpbmctc2VxdWVuY2UtbnVtYmVyIjoiNCJ9LCJnZW5lcmF0ZVRpbWVzdGFtcCI6MTUwOTYwNjM5MjE5MX0",
        "records": [{
            "partition_key": "shardId_0000000000",
            "data": "PEJ1ZmZlcj48L0J1ZmZlcj4=",
            "sequence_number": "0"
        },
        {
            "partition_key": "shardId_0000000000",
            "data": "PEJ1ZmZlcj48L0J1ZmZlcj4=",
            "sequence_number": "1"
        },
        {
            "partition_key": "shardId_0000000000",
            "data": "PEJ1ZmZlcj48L0J1ZmZlcj4=",
            "sequence_number": "2"
        },
        {
            "partition_key": "shardId_0000000000",
            "data": "PEJ1ZmZlcj48L0J1ZmZlcj4=",
            "sequence_number": "3"
        }],
        "millis_behind_latest": ""
    },
    "Tag": "latest",
    "StreamName": "dis-swtest"
}

Timer example event

{
  "version": "v1.0",
  "time": "2006-01-02T15:04:05-07:00",  // Local time
  "trigger_type": "TIMER",   // Trigger type
  "trigger_name": "Trigger name"
  "user_event": "User-defined event"   //Event configured when the timer trigger is created
}

LTS example event

{
    "lts": {
    "data": "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"
    }
}

CTS example event

{
	"cts": {
		"time": "2018/06/26 08:54:07 GMT+08:00", //Timestamp of the sender
		"user": { //Information about the user that initiates the request
			"name": "userName",
			"id": "5b726c4fbfd84821ba866bafaaf56aax",
			"domain": {
				"name": "domainName",
				"id": "b2b3853af40448fcb9e40dxj89505ba"
			}
		},
		"request": {}, //Content of the trace request
		"response": {}, //Content of the trace response
		"code": 204, //Trace response codes, such as, 200 or 400
		"service_type": "FunctionGraph", //Name of the sender in abbreviated form, such as VPC and ECS
		"resource_type": "graph", //Resource type of the sender, such as VM and VPN
		"resource_name": "workflow-2be1", //Resource name, for example, the name of a VM on Elastic Cloud Server (ECS)
		"resource_id": "urn:fgs:xx-xxx-x:2d1d891d93054bbaa69b9e866c0971ac:graph:workflow-2be1", //Resource ID, for example, the ID of a VM on ECS
		"trace_name": "deleteGraph", //Trace name, such as startServer and shutDown
		"trace_type": "ConsoleAction", //Type of the trace source, such as ApiCall
		"record_time": "2018/06/26 08:54:07 GMT+08:00", //Time when CTS receives the trace
		"trace_id": "69be64a7-0233-11e8-82e4-e5d37911193e", //Trace ID
		"trace_status": "normal"
	}
}

Kafka example event

{
    "event_version": "v1.0",
    "event_time": 1576737962,
    "trigger_type": "KAFKA",
    "region": "xx-xxxx-x",
    "messages": [
        "kafka message1",
        "kafka message2",
        "kafka message3",
        "kafka message4",
        "kafka message5"
    ],
    "instance_id": "81335d56-b9fe-4679-ba95-7030949cc76b",
    "topic_id": "topic-test"
}

RabbitMQ example event

{
    "event_version": "v1.0",
    "event_time": 1576737962,
    "trigger_type": "RABBITMQ",
    "region": "{region}",
    "records": [
        {
            "messages": [
                "rabbitmq message1",
                "rabbitmq message2",
                "rabbitmq message3",
                "rabbitmq message4",
                "rabbitmq message5"
            ],
            "instance_id": "81335d56-b9fe-4679-ba95-7030949cc76b",
            "exchange": "exchange-test"
        }
    ]
}

**Table 2** Parameters
Parameter	Type	Example Value	Description
event_version	String	v1.0	Event version
Region	String	xx-xxx-x	Region where the RabbitMQ instance is located. Set it based on the site requirements.
instance_id	String	81335d56-b9fe-4679-ba95-7030949cc76b	RabbitMQ instance ID