EG-based Event Notifications

For details about how to use EG, see Sending a Huawei Cloud Service Event.

1. Click next to the subscription name. In the Configuration name and description dialog box, modify the subscription name and description.

   The subscription name must start with a letter or digit and can contain a maximum of 128 characters, including letters, digits, periods (.), underscores (_), and hyphens (-).

2. Click OK.

If you do not have any specific needs for enterprise project division and management, choose the default enterprise project.

An enterprise project cannot be changed after being configured. Select an appropriate enterprise project based on your service requirements.

1. Click Event Source. The Event Source dialog box is displayed on the right, as shown in Figure 2.
   Figure 2 Configuring an event source
   
2. Select an event source provider.

   Retain the default value, that is, Cloud services.

3. Set event source parameters.

   Table 4 OBS event source parameters

   Parameter	Description
   Event Source	Select a cloud service event source. To use OBS events as the event source, you can select either of the following event sources: OBS Application Service: events about specific operations on bucket objects from OBS To select OBS Application Service as the event source, your account must have the Tenant Administrator permission. For details, see Assigning Dependency Roles. Object Storage Service (OBS): events about bucket and system operations from OBS
   Bucket	This parameter is mandatory when Event Source is set to OBS Application Service. Select the bucket for generating OBS events. OBS events generated due to operations on this bucket or its objects will serve as the event source of EG notifications.
   Event Type	Configure OBS event types that trigger EG notifications based on operations performed on target objects. For example, if you want operations of uploading objects to the bucket to trigger EG notifications, you can select OBS:DWR:ObjectCreated:PUT and OBS:DWR:ObjectCreated:POST. You can specify multiple event types in an EG event notification rule. EG notification rules configured for the same bucket cannot overlap with each other. If the notification rule you are creating overlaps with an existing one, the rule creation will fail. If you delete an object from a bucket with versioning enabled but do not specify the version ID, no object version is deleted by default, and no object deletion event notification will be triggered. Instead, the current object version becomes a historical one, and a delete marker is inserted as the new current version. For details about the OBS event types supported by EG, see Event Types Supported by OBS.
   Object Name Prefix	Optional This parameter is required if you set Event Source to OBS Application Service and need to specify specific objects for which events are generated. OBS events generated due to operations on objects with the specified object name prefix in the bucket will serve as the event source of EG notifications. To match all objects in the bucket, leave both Object Name Prefix and Object Name Suffix empty. To match all objects in the testfolder directory in the root directory of the bucket, set Object Name Prefix to testfolder/ and leave Object Name Suffix empty. To match all JPG objects in the bucket, leave Object Name Prefix empty and set Object Name Suffix to .jpg. To match all MP3 objects in the testfolder directory in the root directory of the bucket, set Object Name Prefix to testfolder/ and Object Name Suffix to .mp3.
   Object Name Suffix	Optional This parameter is required if you set Event Source to OBS Application Service and need to specify specific objects for which events are generated. OBS events generated due to operations on objects with the specified object name suffix in the bucket will serve as the event source of EG notifications. To match all objects in the bucket, leave both Object Name Prefix and Object Name Suffix empty. To match all objects in the testfolder directory in the root directory of the bucket, set Object Name Prefix to testfolder/ and leave Object Name Suffix empty. To match all JPG objects in the bucket, leave Object Name Prefix empty and set Object Name Suffix to .jpg. To match all MP3 objects in the testfolder directory in the root directory of the bucket, set Object Name Prefix to testfolder/ and Object Name Suffix to .mp3.
   Object Name Encoding	Optional This parameter is required if you set Event Source to OBS Application Service and need to encode the names of objects for which events are generated. If the function used in the event target decodes object names, enable this option so that the function can correctly read the object names.
   Filter Rule	Event filter rule. Only events that match the filter rule will be pushed to the event target for subsequent operations. For example, if you want operations of uploading .jpg images to buckets except test-bucket to trigger EG event notifications, perform the following configurations: Event Source: Select OBS Application Service. Bucket: Select test-bucket. Event Type: Select OBS:DWR:ObjectCreated:PUT and OBS:DWR:ObjectCreated:POST. Object Name Suffix: Enter .jpg. Filter Rule: Configure it as follows: { "source": [ { "op": "StringIn", "values": [ "HC.OBS.DWR" ] } ], "type": [ { "op": "StringIn", "values": [ "OBS:DWR:ObjectCreated:PUT", "OBS:DWR:ObjectCreated:POST" ] } ], "subject": { "and": [ { "op": "StringEndsWith", "values": [ ".jpg" ] } ] }, "data": { "obs": { "bucket": { "name": [ { "op": "StringNotIn", "values": [ "test-bucket" ] } ] } } } } For more information about filter rules, see Filter Rule Parameters and Example Filter Rules.

4. Click OK.

1. Click Event Target.
   Figure 3 Configuring an event target
   
2. Set event target parameters.
   • Select Cloud services as the event target provider. After receiving an event notification from the event source, the event target triggers cloud services to perform operations. Set the following parameters:

     Table 5 Selecting Cloud services as the event target provider

     Parameter	Option	Description
     Event Target	Simple Message Notification (SMN)	The event target dispatches tasks to SMN, triggering it to send messages. Set the following parameters: Topic: Select a message topic. You need to create a topic in advance. For details, see Creating a Topic. Agency: It grants EG the smn:topic:publish permission to publish messages. The drop-down list displays only the agencies whose delegatee is EG. Ensure that the selected agency has the smn:topic:publish permission. If no agency is available, click Create Agency to create one named EG_SMN_PUBLISHER_AGENCY. Type: type of the message subject. If you want to specify the message subject in a fixed format, you can configure the message subject. Two types are available: Constants: The subject does not change from specified. All messages will use the same subject. Variables: The subject in the template is a variable value from CloudEvents-compliant events. Max.: 512 characters.
     	FunctionGraph (function computing)	The event target dispatches tasks to FunctionGraph to execute related function operations. Set the following parameters: Function: Select the function to trigger. If no function is available, create a function first. Version/Alias: Choose to specify a version or alias. Version: Select a version of the function. The default value is latest. Alias: Select an alias of the function. Execute: function invocation mode Asynchronously: Immediate responses of function invocation are not required. Synchronously: Immediate responses of function invocation are required. Agency: It grants EG the functiongraph:function:invoke* permission to execute functions synchronously or asynchronously. The drop-down list displays only the agencies whose delegatee is EG. Ensure that the selected agency has the functiongraph:function:invoke* permission. If no agency is available, click Create Agency to create one named EG_TARGET_AGENCY.
     Rule	Transform Type	EG transforms CloudEvents-compliant events for targets. The following three types are supported: Pass-through: Directly route CloudEvents-compliant events to the target. Variables: Route variables in CloudEvents-compliant events to the target. Parameters: parameters that need to be transformed Template: Create a template with the required variables for event transformation. Constants: Route constants in events to the target. For more information about transformation types, see Event Content Transformation.

   • If you select Custom for Provider, set the following parameters:

     Table 6 Selecting Custom for Provider

     Parameter	Option	Description
     URL	URL	Custom event target URL, which is used to consume events You must enter the URL of the event target starting with http:// or https:// and using the POST method. The default timeout for delivering events to the custom event target is 9 seconds. Exceeding this limit will cause delivery failure. The HTTP protocol has high security risks, which may cause data to be eavesdropped or tampered with. To ensure data security, you are advised to use HTTPS. If you must use HTTP, ensure that the custom event does not contain any sensitive information. You are responsible for all related risks.
     	Connection	You can connect to the private webhook through the VPC and subnet connection. For details, see Connections.
     Request Parameters	Headers	You can set request header parameters when requesting a URL. The settings include the request header parameter name, value, and whether encryption is enabled. Figure 4 Headers Key (request header): Enter up to 256 characters starting and ending with a letter. Only letters and hyphens (-) are allowed. Value: Enter up to 1,024 characters. Only letters, hyphens (-), underscores (_), spaces, and the following special characters are allowed: ~!@#$%^&*()=+|[{}];:'",<.>/? NOTE: If the request header and value are invalid, the encryption option is unavailable.
     Rule	Transform Type	EG transforms CloudEvents-compliant events for targets. The following three types are supported: Pass-through: Directly route CloudEvents-compliant events to the target. Variables: Route variables in CloudEvents-compliant events to the target. Parameters: parameters that need to be transformed Template: Create a template with the required variables for event transformation. Constants: Route constants in events to the target. For more information about transformation types, see Event Content Transformation.

3. Click OK.

After an event subscription is created, you can view it in the event subscription list. The subscription status is Enabled by default.

• Disabling or enabling an event subscription
  1. Click Disable or Enable in the upper right corner of the page.
  2. Click Save.

     In the event subscription list, the status of the corresponding subscription is disabled or enabled.

• Modifying an event subscription: Modify the name, description, event source, and event target of the event subscription by referring to 5.

  Currently, the enterprise project to which an event subscription belongs cannot be modified.

• Deleting an event subscription
  1. Click Delete in the upper right corner of the page.
  2. In the Delete Event Subscription dialog box, click Auto Enter. The system automatically enters DELETE.
  3. Click OK.

     If the deleted subscription is not displayed in the event subscription list, the subscription is deleted successfully.

  

  Deleted event subscriptions cannot be restored. Exercise caution when performing this operation.

In the exported table, you can view the notification name, EG subscription name, event, prefix, suffix, EG channel, object name encoding, and OBS message format.