Subscribe to a notification from the Application Details page

Provide the ability to subscribe to a notification from the Application Details page

Summary

Allow users to subscribe application with a notification from the Application Details page using provided instruments for selecting available triggers and services.

Motivation

It is already possible to subscribe to notifications by modifying annotations however this is a pretty poor user experience. Users have to understand annotation structure and have to find available services and triggers in configmap.

Goals

Be able to subscribe to a notification from the Application Details page without forcing users to read the notification configmap.

Non-Goals

We provide only ability to select existing services and triggers, we don't provide instruments to add/edit/delete notification services and triggers.

Proposal

Two changes are required:

• Implement notifications API that would expose a list of configured triggers and services
• Implement UI that leverages notifications API and helps users to create a correct annotation.

Use cases

Add a list of detailed use cases this enhancement intends to take care of.

Use case 1:

As a user, I would like to be able to subscribe application to a notification from the Application Details Page without reading knowing of annotation format and reading notification configmap.

Implementation Details/Notes/Constraints [optional]

Three read-only API endpoints will be added to provide a list of notification services, triggers, and templates.

message Triggers { repeated string triggers = 1; }
message TriggersListRequest {}
message Services { repeated string services = 1; }
message ServicesListRequest {}
message Templates { repeated string templates = 1; }
message TemplatesListRequest {}
service NotificationService {
	rpc ListTriggers(TriggersListRequest) returns (Triggers) {
		option (google.api.http).get = "/api/v1/notifications/triggers";
	}
	rpc ListServices(ServicesListRequest) returns (Services) {
		option (google.api.http).get = "/api/v1/notifications/services";
	}
	rpc ListTemplates(TemplatesListRequest) returns (Templates) {
		option (google.api.http).get = "/api/v1/notifications/templates";
	}
}

Detailed examples

Security Considerations

New API endpoints are available only for authenticated users. API endpoints response does not contain any sensitive data.

Risks and Mitigations

TBD

Upgrade / Downgrade Strategy

By default, we don't have a notification configmap in the system; in that case, API should return an empty list instead of erroring.

Drawbacks

Alternatives

Continue to do that manually.