Add a health indicator for an Elasticsearch cluster

Closes gh-2399

spring-boot-actuator/src/main/java/org/springframework/boot/actuate/autoconfigure/ElasticsearchHealthIndicatorConfiguration.java

@@ -0,0 +1,55 @@
+/*
+ * Copyright 2014 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.boot.actuate.autoconfigure;
+
+import org.elasticsearch.client.Client;
+import org.springframework.boot.actuate.health.ElasticsearchHealthIndicator;
+import org.springframework.boot.actuate.health.ElasticsearchHealthIndicatorProperties;
+import org.springframework.boot.actuate.health.HealthIndicator;
+import org.springframework.boot.autoconfigure.AutoConfigureAfter;
+import org.springframework.boot.autoconfigure.AutoConfigureBefore;
+import org.springframework.boot.autoconfigure.condition.ConditionalOnBean;
+import org.springframework.boot.autoconfigure.condition.ConditionalOnMissingBean;
+import org.springframework.boot.autoconfigure.condition.ConditionalOnProperty;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+
+/**
+ * {@link org.springframework.boot.autoconfigure.EnableAutoConfiguration Auto-configuration} for
+ * {@link org.springframework.boot.actuate.health.ElasticsearchHealthIndicator}.
+ *
+ * @author Binwei Yang
+ * @since 1.2.2
+ */
+@Configuration
+@AutoConfigureBefore({EndpointAutoConfiguration.class})
+@AutoConfigureAfter({HealthIndicatorAutoConfiguration.class})
+@ConditionalOnProperty(prefix = "management.health.elasticsearch", name = "enabled", matchIfMissing = true)
+public class ElasticsearchHealthIndicatorConfiguration {
+
+    @Bean
+    @ConditionalOnBean(Client.class)
+    @ConditionalOnMissingBean(name = "elasticsearchHealthIndicator")
+    public HealthIndicator elasticsearchHealthIndicator() {
+        return new ElasticsearchHealthIndicator();
+    }
+
+    @Bean
+    public ElasticsearchHealthIndicatorProperties elasticsearchHealthIndicatorProperties() {
+        return new ElasticsearchHealthIndicatorProperties();
+    }
+}

spring-boot-actuator/src/main/java/org/springframework/boot/actuate/health/ElasticsearchHealthIndicator.java

@@ -0,0 +1,62 @@
+/*
+ * Copyright 2014 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.boot.actuate.health;
+
+import org.elasticsearch.action.admin.cluster.health.ClusterHealthResponse;
+import org.elasticsearch.client.Client;
+import org.elasticsearch.client.Requests;
+import org.springframework.beans.factory.annotation.Autowired;
+
+/**
+ * Simple implementation of a {@link HealthIndicator} returning health status information for
+ * ElasticSearch cluster.
+ *
+ * @author Binwei Yang
+ * @since 1.2.2
+ */
+public class ElasticsearchHealthIndicator extends ApplicationHealthIndicator {
+    @Autowired
+    private Client client;
+
+    @Autowired
+    private ElasticsearchHealthIndicatorProperties properties;
+
+    @Override
+    protected void doHealthCheck(Health.Builder builder) throws Exception {
+        try {
+            ClusterHealthResponse response = client.admin().cluster().health(Requests.clusterHealthRequest(
+                    properties.getIndexNamesAsArray()
+            )).actionGet(100);
+
+            switch (response.getStatus()) {
+                case GREEN:
+                    builder.up();
+                    break;
+                case RED:
+                    builder.down();
+                    break;
+                case YELLOW:
+                default:
+                    builder.unknown();
+                    break;
+            }
+            builder.withDetail("clusterHealth", response);
+        } catch (Exception handled) {
+            builder.unknown().withDetail("exception", handled);
+        }
+    }
+}

spring-boot-actuator/src/main/java/org/springframework/boot/actuate/health/ElasticsearchHealthIndicatorProperties.java

@@ -0,0 +1,52 @@
+/*
+ * Copyright 2014 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.boot.actuate.health;
+
+import org.springframework.boot.context.properties.ConfigurationProperties;
+
+/**
+ * External configuration properties for {@link ElasticsearchHealthIndicator}
+ *
+ * @author Binwei Yang
+ * @since 1.2.2
+ */
+@ConfigurationProperties("management.health.elasticsearch")
+public class ElasticsearchHealthIndicatorProperties {
+
+    public static final String ALL = "_all";
+
+    /**
+     * comma separated index names. the default includes all indices.
+     */
+    private String indices = ALL;
+
+    public String getIndices() {
+        return indices;
+    }
+
+    public void setIndices(String indices) {
+        this.indices = indices;
+    }
+
+    String[] getIndexNamesAsArray() {
+        if (null == indices) {
+            return new String[]{ALL};
+        } else {
+            return indices.split(",");
+        }
+    }
+}

spring-boot-actuator/src/main/resources/META-INF/spring.factories

@@ -12,4 +12,5 @@ org.springframework.boot.actuate.autoconfigure.MetricFilterAutoConfiguration,\
 org.springframework.boot.actuate.autoconfigure.MetricRepositoryAutoConfiguration,\
 org.springframework.boot.actuate.autoconfigure.PublicMetricsAutoConfiguration,\
 org.springframework.boot.actuate.autoconfigure.TraceRepositoryAutoConfiguration,\
-org.springframework.boot.actuate.autoconfigure.TraceWebFilterAutoConfiguration
+org.springframework.boot.actuate.autoconfigure.TraceWebFilterAutoConfiguration,\
+org.springframework.boot.actuate.autoconfigure.ElasticsearchHealthIndicatorConfiguration