Add slack notifications

spring-boot-admin-docs/src/main/asciidoc/index.adoc

@@ -466,6 +466,45 @@ To enable Hipchat notifications you need to create an API token from you Hipchat
 |
 |===
 
+[slack-notifications]
+==== Slack notifications ====
+To enable Slack notifications you need to add a incoming Webhook under custom integrations on your Slack
+account and configure it appropriately.
+
+.Slack notifications configuration options
+|===
+| Property name |Description |Default value
+
+| spring.boot.admin.notify.slack.enabled
+| Enable Slack notifications
+| `true`
+
+| spring.boot.admin.notify.slack.ignore-changes
+| Comma-delimited list of status changes to be ignored. Format: "<from-status>:<to-status>". Wildcards allowed.
+| `"UNKNOWN:UP"`
+
+| spring.boot.admin.notify.slack.webhook-url
+| The Slack Webhook URL to send notifications
+|
+
+| spring.boot.admin.notify.slack.channel
+| Optional channel name (without # at the beginning). If different than channel in Slack Webhooks settings
+|
+
+| spring.boot.admin.notify.slack.icon
+| Optional icon name (without surrounding colons). If different than icon in Slack Webhooks settings
+|
+
+| spring.boot.admin.notify.slack.username
+| Optional username to send notification if different than in Slack Webhooks settings
+| `Spring Boot Admin`
+
+| spring.boot.admin.notify.slack.message
+| Message to use in the event. SpEL-expressions and Slack markups are supported
+| `+++"*#{application.name}* (#{application.id}) is *#{to.status}*"+++`
+|
+|===
+
 [reminder-notifactaions]
 ==== Reminder notifications ====
 To get reminders for down/offline applications you can add a `RemindingNotifier` to your `ApplicationContext`. The `RemindingNotifier` uses another `Notifier` as delegate to send the reminders.
@@ -496,7 +535,6 @@ public class ReminderConfiguration {
 <1> The reminders will be sent every 5 minutes.
 <2> Schedules sending of due reminders every 60 seconds.
 
-
 [[faqs]]
 == FAQs ==
 [qanda]

spring-boot-admin-server/src/main/java/de/codecentric/boot/admin/config/NotifierConfiguration.java

@@ -39,6 +39,7 @@ import de.codecentric.boot.admin.notify.MailNotifier;
 import de.codecentric.boot.admin.notify.Notifier;
 import de.codecentric.boot.admin.notify.NotifierListener;
 import de.codecentric.boot.admin.notify.PagerdutyNotifier;
+import de.codecentric.boot.admin.notify.SlackNotifier;
 
 @Configuration
 public class NotifierConfiguration {
@@ -123,4 +124,19 @@ public class NotifierConfiguration {
 			return new HipchatNotifier();
 		}
 	}
+
+	@Configuration
+	@ConditionalOnProperty(prefix = "spring.boot.admin.notify.slack", name = "webhook-url")
+	@AutoConfigureBefore({ NotifierListenerConfiguration.class,
+			CompositeNotifierConfiguration.class })
+	public static class SlackNotifierConfiguration {
+		@Bean
+		@ConditionalOnMissingBean
+		@ConditionalOnProperty(prefix = "spring.boot.admin.notify.slack", name = "enabled", matchIfMissing = true)
+		@ConfigurationProperties("spring.boot.admin.notify.slack")
+		public SlackNotifier slackNotifier() {
+			return new SlackNotifier();
+		}
+	}
+
 }

spring-boot-admin-server/src/main/java/de/codecentric/boot/admin/notify/SlackNotifier.java

+package de.codecentric.boot.admin.notify;
+
+import java.net.URI;
+import java.util.Collections;
+import java.util.HashMap;
+import java.util.Map;
+
+import org.springframework.expression.Expression;
+import org.springframework.expression.ParserContext;
+import org.springframework.expression.spel.standard.SpelExpressionParser;
+import org.springframework.web.client.RestTemplate;
+
+import de.codecentric.boot.admin.event.ClientApplicationStatusChangedEvent;
+
+/**
+ * Notifier submitting events to Slack.
+ *
+ * @author Artur Dobosiewicz
+ */
+public class SlackNotifier extends AbstractStatusChangeNotifier {
+	private static final String DEFAULT_MESSAGE = "*#{application.name}* (#{application.id}) is *#{to.status}*";
+
+	private final SpelExpressionParser parser = new SpelExpressionParser();
+	private RestTemplate restTemplate = new RestTemplate();
+
+	/**
+	 * Webhook url for Slack API (i.e. https://hooks.slack.com/services/xxx)
+	 */
+	private URI webhookUrl;
+
+	/**
+	 * Optional channel name without # sign (i.e. somechannel)
+	 */
+	private String channel;
+
+	/**
+	 * Optional emoji icon without colons (i.e. my-emoji)
+	 */
+	private String icon;
+
+	/**
+	 * Optional username which sends notification
+	 */
+	private String username = "Spring Boot Admin";
+
+	/**
+	 * Message formatted using Slack markups. SpEL template using event as root
+	 */
+	private Expression message;
+
+	public SlackNotifier() {
+		this.message = parser.parseExpression(DEFAULT_MESSAGE, ParserContext.TEMPLATE_EXPRESSION);
+	}
+
+	@Override
+	protected void doNotify(ClientApplicationStatusChangedEvent event) throws Exception {
+		restTemplate.postForEntity(webhookUrl, createMessage(event), Void.class);
+	}
+
+	public void setRestTemplate(RestTemplate restTemplate) {
+		this.restTemplate = restTemplate;
+	}
+
+	public void setWebhookUrl(URI webhookUrl) {
+		this.webhookUrl = webhookUrl;
+	}
+
+	public void setChannel(String channel) {
+		this.channel = channel;
+	}
+
+	public void setIcon(String icon) {
+		this.icon = icon;
+	}
+
+	public void setUsername(String username) {
+		this.username = username;
+	}
+
+	public void setMessage(Expression message) {
+		this.message = message;
+	}
+
+	private Object createMessage(ClientApplicationStatusChangedEvent event) {
+		Map<String, Object> messageJson = new HashMap<>();
+		messageJson.put("username", username);
+		if (icon != null) {
+			messageJson.put("icon_emoji", ":" + icon + ":");
+		}
+		if (channel != null) {
+			messageJson.put("channel", channel);
+		}
+
+		Map<String, Object> attachments = new HashMap<>();
+		attachments.put("text", getText(event));
+		attachments.put("color", getColor(event));
+		attachments.put("mrkdwn_in", Collections.singletonList("text"));
+
+		messageJson.put("attachments", Collections.singletonList(attachments));
+
+		return messageJson;
+	}
+
+	private String getText(ClientApplicationStatusChangedEvent event) {
+		return message.getValue(event, String.class);
+	}
+
+	private String getColor(ClientApplicationStatusChangedEvent event) {
+		return "UP".equals(event.getTo().getStatus()) ? "good" : "danger";
+	}
+}

spring-boot-admin-server/src/test/java/de/codecentric/boot/admin/config/NotifierConfigurationTest.java

@@ -43,6 +43,7 @@ import de.codecentric.boot.admin.notify.MailNotifier;
 import de.codecentric.boot.admin.notify.Notifier;
 import de.codecentric.boot.admin.notify.NotifierListener;
 import de.codecentric.boot.admin.notify.PagerdutyNotifier;
+import de.codecentric.boot.admin.notify.SlackNotifier;
 
 public class NotifierConfigurationTest {
 	private static final ClientApplicationEvent APP_DOWN = new ClientApplicationStatusChangedEvent(
@@ -92,6 +93,12 @@ public class NotifierConfigurationTest {
 	}
 
 	@Test
+	public void test_slack() {
+		load(null, "spring.boot.admin.notify.slack.webhook-url:http://example.com");
+		assertThat(context.getBean(SlackNotifier.class), is(instanceOf(SlackNotifier.class)));
+	}
+
+	@Test
 	public void test_multipleNotifiers() {
 		load(TestMultipleNotifierConfig.class);
 		assertThat(context.getBean(Notifier.class), is(instanceOf(CompositeNotifier.class)));

spring-boot-admin-server/src/test/java/de/codecentric/boot/admin/notify/SlackNotifierTest.java

+package de.codecentric.boot.admin.notify;
+
+import static org.mockito.Matchers.any;
+import static org.mockito.Matchers.eq;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.verify;
+
+import java.net.URI;
+import java.util.Collections;
+import java.util.HashMap;
+import java.util.Map;
+
+import javax.annotation.Nullable;
+
+import org.junit.Before;
+import org.junit.Test;
+import org.springframework.expression.Expression;
+import org.springframework.expression.ParserContext;
+import org.springframework.expression.spel.standard.SpelExpressionParser;
+import org.springframework.web.client.RestTemplate;
+
+import de.codecentric.boot.admin.event.ClientApplicationStatusChangedEvent;
+import de.codecentric.boot.admin.model.Application;
+import de.codecentric.boot.admin.model.StatusInfo;
+
+public class SlackNotifierTest {
+	private static final String channel = "channel";
+	private static final String icon = "icon";
+	private static final String user = "user";
+	private static final String appName = "App";
+	private static final String id = "-id-";
+	private static final String message = "test";
+
+	private SlackNotifier notifier;
+	private RestTemplate restTemplate;
+
+	@Before
+	public void setUp() {
+		restTemplate = mock(RestTemplate.class);
+		notifier = new SlackNotifier();
+		notifier.setUsername(user);
+		notifier.setWebhookUrl(URI.create("http://localhost/"));
+		notifier.setRestTemplate(restTemplate);
+	}
+
+	@Test
+	public void test_onApplicationEvent_resolve() {
+		StatusInfo infoDown = StatusInfo.ofDown();
+		StatusInfo infoUp = StatusInfo.ofUp();
+
+		notifier.setChannel(channel);
+		notifier.setIcon(icon);
+		notifier.notify(getEvent(infoDown, infoUp));
+
+		Object expected = expectedMessage("good", user, icon, channel,
+				standardMessage(infoUp.getStatus(), appName, id));
+
+		verify(restTemplate).postForEntity(any(URI.class), eq(expected), eq(Void.class));
+	}
+
+	@Test
+	public void test_onApplicationEvent_resolve_without_channel_and_icon() {
+		StatusInfo infoDown = StatusInfo.ofDown();
+		StatusInfo infoUp = StatusInfo.ofUp();
+
+		notifier.notify(getEvent(infoDown, infoUp));
+
+		Object expected = expectedMessage("good", user, null, null,
+				standardMessage(infoUp.getStatus(), appName, id));
+
+		verify(restTemplate).postForEntity(any(URI.class), eq(expected), eq(Void.class));
+	}
+
+	@Test
+	public void test_onApplicationEvent_resolve_with_given_user() {
+		StatusInfo infoDown = StatusInfo.ofDown();
+		StatusInfo infoUp = StatusInfo.ofUp();
+		String anotherUser = "another user";
+
+		notifier.setUsername(anotherUser);
+		notifier.setChannel(channel);
+		notifier.setIcon(icon);
+		notifier.notify(getEvent(infoDown, infoUp));
+
+		Object expected = expectedMessage("good", anotherUser, icon, channel,
+				standardMessage(infoUp.getStatus(), appName, id));
+
+		verify(restTemplate).postForEntity(any(URI.class), eq(expected), eq(Void.class));
+	}
+
+	@Test
+	public void test_onApplicationEvent_resolve_with_given_message() {
+		StatusInfo infoDown = StatusInfo.ofDown();
+		StatusInfo infoUp = StatusInfo.ofUp();
+
+		Expression expression = new SpelExpressionParser().parseExpression(message,
+				ParserContext.TEMPLATE_EXPRESSION);
+		notifier.setMessage(expression);
+		notifier.setChannel(channel);
+		notifier.setIcon(icon);
+		notifier.notify(getEvent(infoDown, infoUp));
+
+		Object expected = expectedMessage("good", user, icon, channel, message);
+
+		verify(restTemplate).postForEntity(any(URI.class), eq(expected), eq(Void.class));
+	}
+
+	@Test
+	public void test_onApplicationEvent_trigger() {
+		StatusInfo infoDown = StatusInfo.ofDown();
+		StatusInfo infoUp = StatusInfo.ofUp();
+
+		notifier.setChannel(channel);
+		notifier.setIcon(icon);
+		notifier.notify(getEvent(infoUp, infoDown));
+
+		Object expected = expectedMessage("danger", user, icon, channel,
+				standardMessage(infoDown.getStatus(), appName, id));
+
+		verify(restTemplate).postForEntity(any(URI.class), eq(expected), eq(Void.class));
+	}
+
+	private ClientApplicationStatusChangedEvent getEvent(StatusInfo infoDown, StatusInfo infoUp) {
+		return new ClientApplicationStatusChangedEvent(
+				Application.create(appName).withId(id).withHealthUrl("http://health").build(),
+				infoDown, infoUp);
+	}
+
+	private Object expectedMessage(String color, String user, @Nullable String icon,
+			@Nullable String channel, String message) {
+		Map<String, Object> messageJson = new HashMap<>();
+		messageJson.put("username", user);
+		if (icon != null) {
+			messageJson.put("icon_emoji", ":" + icon + ":");
+		}
+		if (channel != null) {
+			messageJson.put("channel", channel);
+		}
+
+		Map<String, Object> attachments = new HashMap<>();
+		attachments.put("text", message);
+		attachments.put("color", color);
+		attachments.put("mrkdwn_in", Collections.singletonList("text"));
+
+		messageJson.put("attachments", Collections.singletonList(attachments));
+
+		return messageJson;
+	}
+
+	private String standardMessage(String status, String appName, String id) {
+		return "*" + appName + "* (" + id + ") is *" + status + "*";
+	}
+}