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 Using an SMN Trigger.

APIG

API Gateway (APIG) is an API hosting service that helps enterprises to build, manage, and deploy APIs at any scale. With APIG, 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. APIG invokes the relevant function when an HTTPS request (APIG example event) is sent to the API backend. For details, see Using an APIG Trigger.

DIS

Data Ingestion Service (DIS) can ingest large amounts of data in real time. You can create a function to automatically poll a DIS stream and process all new data records, such as website click streams, financial transactions, social media streams, IT logs, and location-tracking events (DIS example event). FunctionGraph periodically polls the stream for new data records. For details, see Using a DIS Trigger.

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 Using a Timer Trigger.

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 Using a Kafka Trigger.

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 Viewing Function Metrics.

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

{
    "record": [
        {
            "event_version": "1.0",
            "smn": {
                "topic_urn": "urn:smn:{region}:0162c0f220284698b77a3d264376343a:{function_name}",
                "timestamp": "2018-01-09T07:11:40Z",
                "message_attributes": null,
                "message": "this is smn message content",
                "type": "notification",
                "message_id": "a51671f77d4a479cacb09e2cd591a983",
                "subject": "this is smn message subject"
            },
            "event_subscription_urn": "urn:fss:{region}:0162c0f220284698b77a3d264376343a:function:default:read-smn-message:latest",
            "event_source": "smn"
        }
],
    "functionname": "test",
    "requestId": "7c307f6a-cf68-4e65-8be0-4c77405a1b2c",
    "timestamp": "Wed Nov 15 2017 12:00:00 GMT+0800 (CST)"
}

**Table 1** Parameter description
Parameter	Type	Example Value	Description
event_version	String	1.0	Event version
topic_urn	String	See the example.	ID of an SMN event
type	String	notification	Event type
RequestID	String	7c307f6a-cf68-4e65-8be0-4c77405a1b2c	Request ID. The ID of each request is unique.
message_id	String	a51671f77d4a479cacb09e2cd591a983	Message ID. The ID of each message is unique.
Message	String	this is smn message content	Message content
event_source	String	smn	Event source
event_subscription_urn	String	See the example.	Subscription ID
timestamp	String	Wed Nov 15 2017 12:00:00 GMT+0800 (CST)	Time when an event occurs

APIG example event

{
    "body": "{\"test\":\"body\"}",
    "requestContext": {
        "apiId": "bc1dcffd-aa35-474d-897c-d53425a4c08e",
        "requestId": "11cdcdcf33949dc6d722640a13091c77",
        "stage": "RELEASE"
    },
    "queryStringParameters": {
        "responseType": "html"
    },
    "httpMethod": "GET",
"pathParameters": {
"path":"value"
},
    "headers": {
        "accept-language": "en-US;q=0.3,en;q=0.2",
        "accept-encoding": "gzip, deflate, br",
        "x-forwarded-port": "443",
        "x-forwarded-for": "103.218.216.98",
        "accept": "text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8",
        "upgrade-insecure-requests": "1",
        "host": "50eedf92-c9ad-4ac0-827e-d7c11415d4f1.apigw.region.cloud.com",
        "x-forwarded-proto": "https",
        "pragma": "no-cache",
        "cache-control": "no-cache",
        "x-real-ip": "103.218.216.98",
        "user-agent": "Mozilla/5.0 (Windows NT 6.1; Win64; x64; rv:57.0) Gecko/20100101 Firefox/57.0"
    },
    "path": "/apig-event-template",
    "isBase64Encoded": true
}

When calling a function using APIG, isBase64Encoded is valued true by default, indicating that the request body transferred to FunctionGraph is encoded using Base64 and must be decoded for processing.

The function must return characters strings by using the following structure.

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

**Table 2** Parameter description
Parameter	Type	Example Value	Description
body	String	"{\"test\":\"body\"}"	Actual request in string format
requestContext	Map	See the example.	Request information, including the API gateway configuration, request ID, authentication information, and source
httpMethod	String	GET	HTTP method
queryStringParameters	Map	See the example.	Query strings configured in APIG and their actual values
pathParameters	Map	See the example.	Path parameters configured in APIG and their actual values
headers	Map	See the example.	Complete headers
path	String	/apig-event-template	Complete path
isBase64Encoded	Boolean	True	Default value: true

DIS example event

{
    "ShardID": "shardId-0000000000",
    "Message": {
        "next_partition_cursor": "eyJnZXRJdGVyYXRvclBhcmFtIjp7InN0cmVhbS1uYW1lIjoiZGlzLXN3dGVzdCIsInBhcnRpdGlvbi1pZCI6InNoYXJkSWQtMDAwMDAwMDAwMCIsImN1cnNvci10eXBlIjoiVFJJTV9IT1JJWk9OIiwic3RhcnRpbmctc2VxdWVuY2UtbnVtYmVyIjoiNCJ9LCJnZW5lcmF0ZVRpbWVzdGFtcCI6MTUwOTYwNjM5MjE5MX0",
        "records": [
            {
                "partition_key": "shardId_0000000000",
                "data": "d2VsY29tZQ==",
                "sequence_number": "0"
            },
            {
                "partition_key": "shardId_0000000000",
                "data": "dXNpbmc=",
                "sequence_number": "1"
            },
            {
                "partition_key": "shardId_0000000000",
                "data": "RnVuY3Rpb25TdGFnZQ==",
                "sequence_number": "2"
            },
            {
                "partition_key": "shardId_0000000000",
                "data": "c2VydmljZQ==",
                "sequence_number": "3"
            }
        ],
        "millis_behind_latest": ""
    },
    "Tag": "latest",
    "StreamName": "dis-swtest"
}

**Table 3** Parameter description
Parameter	Type	Example Value	Description
ShardID	String	shardId-0000000000	Partition ID
next_partition_cursor	String	See the example.	Next partition cursor
Records	Map	See the example.	Data records stored in a DIS stream
partition_key	String	See the example.	Partition key
data	String	See the example.	Data blocks, which are added by the data producer to the stream
sequence_number	Int	See the example.	Record ID, which is automatically allocated by DIS
Tag	String	latest	Stream tag
StreamName	String	dis-swtest	Stream name

Timer example event

{
    "version": "v1.0",
    "time": "2018-06-01T08:30:00+08:00",
    "trigger_type": "TIMER",
    "trigger_name": "Timer_001",
    "user_event": "User Event"
}

**Table 4** Parameter description
Parameter	Type	Example Value	Description
version	String	V1.0	Event version
time	String	2018-06-01T08:30:00+08:00	Time when an event occurs.
trigger_type	String	TIMER	Trigger type
trigger_name	String	Timer_001	Trigger name
user_event	String	User Event	Additional information of the trigger

Kafka example event

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

**Table 5** Parameter description
Parameter	Type	Example Value	Description
event_version	String	v1.0	Event version
event_time	String	2018-01-09T07:50:50.028Z	Time when an event occurs
trigger_type	String	KAFKA	Event type
region	String	ap-southeast-3	Region where a Kafka instance resides
instance_id	String	81335d56-b9fe-4679-ba95-7030949cc76b	Kafka instance ID
messages	String	See the example.	Message content
topic_id	String	topic-test	Message ID

GeminiDB example event

{
    "records": [
        {
            "event_name": "\"insert\"",
            "event_version": "1.0",
            "event_source": "gemini_mongo",
            "region": "{region}",
            "gemini_mongo": {
                "full_document": "{\"_id\": {\"$oid\":\"5f61de944778db5fcded3f87\"},\"zhangsan\": \"zhangsan\"}",
                "ns": "{\"db\": \"zhangsan\",\"coll\": \"zhangsan\"}",
                "size_bytes": "100",
                "token": "{\"_data\": \"825F61DE940000000129295A1004A2D9AE61206C43A5AF47CAF7C5C00C5946645F696400645F61DE944778DB5FCDED3F870004\"}"
            },
            "event_source_id": "51153d19-2b7d-402c-9a79-757163258a36"
        }
    ],
    "vernier": "{\"_data\": \"825F61DE940000000129295A1004A2D9AE61206C43A5AF47CAF7C5C00C5946645F696400645F61DE944778DB5FCDED3F870004\"}"
}

**Table 6** Parameter description
Parameter	Type	Example Value	Description
region	String	ap-southeast-3	Region where a GeminiDB instance resides
event_source	String	gemini_mongo	Event source
event_version	String	1.0	Event version
full_document	String	See the example.	Complete file information
size_bytes	Int	100	Message bytes
token	String	See the example.	Base64-encoded data
vernier	String	See the example.	Cursor

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 7** Parameter description
Parameter	Type	Example Value	Description
event_version	String	v1.0	Event version
Region	String	ap-southeast-3	Region where a RabbitMQ instance resides
instance_id	String	81335d56-b9fe-4679-ba95-7030949cc76b	RabbitMQ instance ID