Add reactive health check.

Closes gh-783

spring-vault-core/src/main/java/org/springframework/vault/core/ReactiveVaultOperations.java

@@ -64,6 +64,12 @@ public interface ReactiveVaultOperations {
 	 */
 	ReactiveVaultTransitOperations opsForTransit(String path);
 
+	/**
+	 * @return the operations interface administrative Vault access.
+	 * @since 3.1
+	 */
+	ReactiveVaultSysOperations opsForSys();
+
 	/**
 	 * Read from a Vault path. Reading data using this method is suitable for API
 	 * calls/secret backends that do not require a request body.

spring-vault-core/src/main/java/org/springframework/vault/core/ReactiveVaultSysOperations.java

@@ -0,0 +1,47 @@
+/*
+ * Copyright 2016-2023 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
+ *
+ *      https://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.vault.core;
+
+import reactor.core.publisher.Mono;
+
+import org.springframework.vault.VaultException;
+import org.springframework.vault.support.VaultHealth;
+
+/**
+ * Interface that specifies a basic set of administrative Vault operations using reactive
+ * infrastructure.
+ *
+ * @author Mark Paluch
+ * @since 3.1
+ */
+public interface ReactiveVaultSysOperations {
+
+	/**
+	 * @return {@literal true} if Vault is initialized.
+	 * @see <a href="https://www.vaultproject.io/docs/http/sys-init.html">GET
+	 * /sys/init</a>
+	 */
+	Mono<Boolean> isInitialized() throws VaultException;
+
+	/**
+	 * Return the health status of Vault.
+	 * @return the {@link VaultHealth}.
+	 * @see <a href="https://www.vaultproject.io/docs/http/sys-health.html">GET
+	 * /sys/health</a>
+	 */
+	Mono<VaultHealth> health() throws VaultException;
+
+}

spring-vault-core/src/main/java/org/springframework/vault/core/ReactiveVaultSysTemplate.java

@@ -0,0 +1,75 @@
+/*
+ * Copyright 2016-2023 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
+ *
+ *      https://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.vault.core;
+
+import java.util.Map;
+
+import org.springframework.http.HttpEntity;
+import org.springframework.util.Assert;
+import org.springframework.vault.client.VaultHttpHeaders;
+import org.springframework.vault.support.VaultHealth;
+
+import reactor.core.publisher.Mono;
+
+/**
+ * Default implementation of {@link ReactiveVaultSysOperations}.
+ *
+ * @author Mark Paluch
+ */
+public class ReactiveVaultSysTemplate implements ReactiveVaultSysOperations {
+
+	private final ReactiveVaultOperations vaultOperations;
+
+	/**
+	 * Create a new {@link ReactiveVaultSysTemplate} with the given
+	 * {@link ReactiveVaultOperations}.
+	 * @param vaultOperations must not be {@literal null}.
+	 */
+	public ReactiveVaultSysTemplate(ReactiveVaultOperations vaultOperations) {
+
+		Assert.notNull(vaultOperations, "ReactiveVaultOperations must not be null");
+
+		this.vaultOperations = vaultOperations;
+
+	}
+
+	@Override
+	public Mono<Boolean> isInitialized() {
+
+		return this.vaultOperations.doWithSession(webClient -> {
+			return webClient.get()
+				.uri("sys/init")
+				.header(VaultHttpHeaders.VAULT_NAMESPACE, "")
+				.exchangeToMono(clientResponse -> clientResponse.toEntity(Map.class))
+				.map(it -> (Boolean) it.getBody().get("initialized"));
+		});
+	}
+
+	@Override
+	public Mono<VaultHealth> health() {
+
+		return this.vaultOperations.doWithVault(webClient -> {
+
+			return webClient.get()
+				.uri("sys/health")
+				.header(VaultHttpHeaders.VAULT_NAMESPACE, "")
+				.exchangeToMono(clientResponse -> {
+					return clientResponse.toEntity(VaultSysTemplate.VaultHealthImpl.class).map(HttpEntity::getBody);
+				});
+		});
+	}
+
+}

spring-vault-core/src/main/java/org/springframework/vault/core/ReactiveVaultTemplate.java

@@ -227,6 +227,11 @@ private ExchangeFilterFunction getSessionFilter() {
 		}));
 	}
 
+	@Override
+	public ReactiveVaultSysOperations opsForSys() {
+		return new ReactiveVaultSysTemplate(this);
+	}
+
 	@Override
 	public ReactiveVaultTransitOperations opsForTransit() {
 		return opsForTransit("transit");

spring-vault-core/src/main/java/org/springframework/vault/core/VaultSysTemplate.java

@@ -398,8 +398,7 @@ public VaultHealth doWithRestOperations(RestOperations restOperations) {
 			catch (RestClientResponseException responseError) {
 
 				try {
-					ObjectMapper mapper = new ObjectMapper();
-					return mapper.readValue(responseError.getResponseBodyAsString(), VaultHealthImpl.class);
+					return OBJECT_MAPPER.readValue(responseError.getResponseBodyAsString(), VaultHealthImpl.class);
 				}
 				catch (Exception jsonError) {
 					throw responseError;

spring-vault-core/src/test/java/org/springframework/vault/core/ReactiveVaultSysTemplateIntegrationTests.java

@@ -0,0 +1,70 @@
+/*
+ * Copyright 2016-2023 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
+ *
+ *      https://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.vault.core;
+
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.extension.ExtendWith;
+
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.test.context.ContextConfiguration;
+import org.springframework.test.context.junit.jupiter.SpringExtension;
+import org.springframework.vault.util.IntegrationTestSupport;
+import org.springframework.vault.util.RequiresVaultVersion;
+
+import reactor.test.StepVerifier;
+
+import static org.assertj.core.api.Assertions.*;
+
+/**
+ * Integration tests for {@link ReactiveVaultSysTemplate} through
+ * {@link ReactiveVaultSysOperations}.
+ *
+ * @author Mark Paluch
+ */
+@ExtendWith(SpringExtension.class)
+@ContextConfiguration(classes = VaultIntegrationTestConfiguration.class)
+class ReactiveVaultSysTemplateIntegrationTests extends IntegrationTestSupport {
+
+	@Autowired
+	ReactiveVaultOperations vaultOperations;
+
+	ReactiveVaultSysOperations adminOperations;
+
+	@BeforeEach
+	void before() {
+		this.adminOperations = this.vaultOperations.opsForSys();
+	}
+
+	@Test
+	@RequiresVaultVersion("0.6.1")
+	void shouldReportHealth() {
+
+		this.adminOperations.health().as(StepVerifier::create).assertNext(health -> {
+			assertThat(health.isInitialized()).isTrue();
+			assertThat(health.isSealed()).isFalse();
+			assertThat(health.isPerformanceStandby()).isFalse();
+			assertThat(health.isRecoveryReplicationSecondary()).isFalse();
+			assertThat(health.isStandby()).isFalse();
+		}).verifyComplete();
+	}
+
+	@Test
+	void isInitializedShouldReturnTrue() {
+		this.adminOperations.isInitialized().as(StepVerifier::create).expectNext(true).verifyComplete();
+	}
+
+}