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Notifications

You can add your own Notifiers by adding Spring Beans which implement the Notifier interface, at best by extendingAbstractEventNotifier or AbstractStatusChangeNotifier.

CustomNotifier.java
public class CustomNotifier extends AbstractEventNotifier {

    private static final Logger LOGGER = LoggerFactory.getLogger(CustomNotifier.class);

    public CustomNotifier(InstanceRepository repository) {
        super(repository);
    }

    @Override
    protected Mono<Void> doNotify(InstanceEvent event, Instance instance) {
        return Mono.fromRunnable(() -> {
            if (event instanceof InstanceStatusChangedEvent statusChangedEvent) {
                LOGGER.info("Instance {} ({}) is {}", instance.getRegistration().getName(), event.getInstance(),
                        statusChangedEvent.getStatusInfo().getStatus());
            }
            else {
                LOGGER.info("Instance {} ({}) {}", instance.getRegistration().getName(), event.getInstance(),
                        event.getType());
            }
        });
    }
}

Notification Proxy Settings​

All Notifiers which are using a RestTemplate can be configured to use a proxy.

Notification Proxy configuration options
PropertyDescription
spring.boot.admin.notify.proxy.host

Proxy-Host for sending notifications

Type: 
java.lang.String
spring.boot.admin.notify.proxy.port

Proxy-Port for sending notifications

Type: 
java.lang.Integer
0
spring.boot.admin.notify.proxy.password

Proxy-Password for sending notifications (if proxy requires authentication).

Type: 
java.lang.String
spring.boot.admin.notify.proxy.username

Proxy-User for sending notifications (if proxy requires authentication).

Type: 
java.lang.String

Notification Reminder​

The RemindingNotifier sends reminders for down/offline applications, it delegates the sending of notifications to another notifier.

By default, a reminder is triggered when a registered application changes to DOWN or OFFLINE. You can alter this behaviour via setReminderStatuses(). The reminder ends when either the status changes to a non-triggering status or the regarding application gets deregistered.

By default, the reminders are sent every 10 minutes, to change this use setReminderPeriod(). The RemindingNotifier itself doesn’t start the background thread to send the reminders, you need to take care of this as shown in the given example below;

How to configure reminders

NotifierConfiguration.java
@Configuration
public class NotifierConfiguration {
    @Autowired
    private Notifier notifier;

    @Primary
    @Bean(initMethod = "start", destroyMethod = "stop")
    public RemindingNotifier remindingNotifier() {
        RemindingNotifier notifier = new RemindingNotifier(notifier, repository);
        notifier.setReminderPeriod(Duration.ofMinutes(10)); // (1)
        notifier.setCheckReminderInverval(Duration.ofSeconds(10)); //(2)
        return notifier;
    }
}
  1. The reminders will be sent every 10 minutes.
  2. Schedules sending of due reminders every 10 seconds.

Filtering Notifications​

The FilteringNotifier allows you to filter certain notification based on rules you can add/remove at runtime. It delegates the sending of notifications to another notifier.

If you add a FilteringNotifier to your ApplicationContext a RESTful interface on notifications/filter gets available. The restful interface provides the following methods for getting, adding, and deleting notification filters:

  • GET notifications/filter
  • Returns a list of all registered notification filters. Each containing the attributes id, applicationName, expiry, and expired.
  • POST notifications/filters?instanceId=<yourInstanceId>&applicationName=<yourApplicationName>&ttl=<yourInstant>
  • Posts a new notification filter for the application/instance of the given instanceId or applicationName. Either instanceId or applicationName must be set. The parameter ttl is optional and represents the expiration of the filter as an instant (the number of seconds from the epoch of 1970-01-01T00:00:00Z).
  • DELETE notifications/filters/{id}
  • Deletes the notification filter with the requested id from the filters.

You may as well access all notification filter configurations via the main applications view inside SBA client, as seen in the screenshot below.

Sample notification filters

A FilteringNotifier might be useful, for instance, if you don’t want to receive notifications when deploying your applications. Before stopping the application, you can add an (expiring) filter via a POST request.

How to configure filtering

NotifierConfig.java
@Configuration(proxyBeanMethods = false)
public class NotifierConfig {

    private final InstanceRepository repository;

    private final ObjectProvider<List<Notifier>> otherNotifiers;

    public NotifierConfig(InstanceRepository repository, ObjectProvider<List<Notifier>> otherNotifiers) {
        this.repository = repository;
        this.otherNotifiers = otherNotifiers;
    }

    @Bean
    public FilteringNotifier filteringNotifier() { // (1)
        CompositeNotifier delegate = new CompositeNotifier(this.otherNotifiers.getIfAvailable(Collections::emptyList));
        return new FilteringNotifier(delegate, this.repository);
    }

    @Primary
    @Bean(initMethod = "start", destroyMethod = "stop")
    public RemindingNotifier remindingNotifier() { // (2)
        RemindingNotifier notifier = new RemindingNotifier(filteringNotifier(), this.repository);
        notifier.setReminderPeriod(Duration.ofMinutes(10));
        notifier.setCheckReminderInverval(Duration.ofSeconds(10));
        return notifier;
    }

}
  1. Add the FilteringNotifier bean using a delegate (e.g. MailNotifier when configured)
  2. Add the RemindingNotifier as primary bean using the FilteringNotifier as delegate.
tip

This example combines the reminding and filtering notifiers. This allows you to get notifications after the deployed application hasn’t restarted in a certain amount of time (until the filter expires).

Shipped Notifiers​