Webhook

Overview

Export evaluation data by calling a HTTP Webhook.

Everytime the FlushInterval or MaxEventInMemory is reached an HTTP call will be emitted to the Webhook exporter.

info

If for some reason the Webhook HTTP call fails, we will keep the data in memory and retry to add the next time we reach FlushInterval or MaxEventInMemory.

Webhook format

If you have configured a webhook, a POST request will be sent to the EndpointURL with a body in this format:

{
    "meta": {
        "hostname": "server01",
        // ...
    },
    "events": [
        {
            "kind": "feature",
            "contextKind": "anonymousUser",
            "userKey": "14613538188334553206",
            "creationDate": 1618909178,
            "key": "test-flag",
            "variation": "Default",
            "value": false,
            "default": false,
            "source": "SERVER"
        },
        // ...
    ]
}

Signature

This header X-Hub-Signature-256 is sent if the webhook is configured with a secret. This is the HMAC hex digest of the request body, and is generated using the SHA-256 hash function and the secret as the HMAC key.

caution

The recommendation is to always use the Secret and on your API/webhook always verify the signature key to be sure that you don't get into a man-in-the-middle attack.

Configure the relay proxy

To configure your relay proxy to use the Webhook exporter, you need to add the following configuration to your relay proxy configuration file:

goff-proxy.yaml

# ...
exporter:
  kind: webhook
  endpointUrl: https://your-webhook-url.com/
# ...

Field name	Mandatory	Type	Default	Description
kind		string	none	Value should be webhook. This field is mandatory and describes which retriever you are using.
endpointUrl		string	none	EndpointURL of your webhook.
flushInterval		int	60000	The interval in millisecond between 2 calls to the webhook (if the maxEventInMemory is reached before the flushInterval we will call the exporter before).
maxEventInMemory		int	100000	If we hit that limit we will call the exporter.
secret		string	none	Secret used to sign your request body and fill the X-Hub-Signature-256 header. See signature section for more details.
meta		map[string]string	none	Add all the information you want to see in your request.
headers		map[string][]string	none	Add all the headers you want to add while calling the endpoint

Configure the GO Module

To configure your GO module to use the Webhook exporter, you need to add the following configuration to your ffclient.Config{} object:

example.go

config := ffclient.Config{
    // ...
   DataExporter: ffclient.DataExporter{
        // ...
        Exporter: &webhookexporter.Exporter{
            EndpointURL: " https://webhook.url/",
            Secret:      "secret-for-signing",
            Meta:        map[string]string{
                "extraInfo": "info",
            },
            Headers: map[string][]string{
                "Authorization": {"Bearer auth_token"},
            },
        },
    },
    // ...
}
err := ffclient.Init(config)
defer ffclient.Close()

Field	Mandatory	Description
EndpointURL		EndpointURL of your webhook
Secret		Secret used to sign your request body and fill the X-Hub-Signature-256 header. See signature section for more details.
Meta		Add all the information you want to see in your request.
Headers		List of Headers to send to the endpoint