Configure an external HTTP service trigger to forward blockchain events to your application or a third-party service. When BaaS detects a matching event on the blockchain, it sends an HTTP request to the URL you specify.
Prerequisites
Before you begin, ensure that you have:
Installed the cloud service integration module on the target organization
Configure an external HTTP service trigger
In the My Organizations section, find the target organization and click Cloud service integration.
Click the External HTTP service tab.
Click Add configuration. In the Add external HTTP service configuration pane, set the following parameters:
Parameter Description Name A name for the trigger. Used for identification only. Channel/network The fabric channel the trigger listens on and pushes events from. Event type The type of blockchain events to push. For available event types, see Subscribe to events. URL The HTTP or HTTPS endpoint of the external service. Method The HTTP method used to call the endpoint. Supported values: GET,POST.Authentication method The authentication method for the endpoint. See Authentication methods below. Failure threshold Advanced. The number of delivery failures after which the trigger enters the failed state and stops processing. Set to -1to disable the threshold (the trigger never enters the failed state).Filter Advanced. Optional. To push only specific events, configure a filter. See Use Filter. Click Add. The trigger appears in the list.
Authentication methods
| Method | Description |
|---|---|
none | No authentication. |
basic | Basic authentication using a username and password. |
bearer | Bearer token authentication using an HTTP bearer token. |
Manage triggers
After creating a trigger, you can perform the following operations from the trigger list:
| Operation | Description |
|---|---|
| Enable | Starts pushing events to the external service. After enabling, the trigger pushes events starting from the latest block. Events generated while the trigger was disabled are discarded. |
| Disable | Stops event pushes to the external service. |
| Delete | Removes the trigger. |
How failure handling works
When the external service returns an error or the request fails, the trigger retries delivery. If all retry attempts fail, the event is discarded and counted as one failure.
The Block height field shows the latest block the trigger has processed, reflecting its progress.
Trigger status:
Exception: Appears when a service error or parameter configuration error occurs. Move the pointer over Exception to view the error details.
Failed: Appears when the aggregate number of failures exceeds the failure threshold. The trigger stops processing in this state.
To recover from the failed state: Repair the trigger or the external service, then click Enable. The failure count resets to zero and the trigger resumes processing.