Retry mechanism

pom.xml

@@ -22,6 +22,7 @@
 	<modules>
 		<module>spring-cloud-vault-dependencies</module>
 		<module>spring-cloud-vault-config</module>
+		<module>spring-cloud-vault-config-tests</module>
 		<module>spring-cloud-vault-config-databases</module>
 		<module>spring-cloud-vault-config-consul</module>
 		<module>spring-cloud-vault-config-rabbitmq</module>

spring-cloud-vault-config-tests/pom.xml

@@ -0,0 +1,71 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+		 xmlns="http://maven.apache.org/POM/4.0.0"
+		 xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
+	<modelVersion>4.0.0</modelVersion>
+
+	<parent>
+		<groupId>org.springframework.cloud</groupId>
+		<artifactId>spring-cloud-vault-parent</artifactId>
+		<version>3.0.2-SNAPSHOT</version>
+		<relativePath>..</relativePath>
+	</parent>
+
+	<artifactId>spring-cloud-vault-config-tests</artifactId>
+	<name>Spring Cloud Vault Config Tests</name>
+	<description>Module for testing spring-cloud-vault-config with a limited number of dependencies</description>
+
+	<dependencies>
+		<dependency>
+			<groupId>org.springframework.cloud</groupId>
+			<artifactId>spring-cloud-starter-vault-config</artifactId>
+			<version>${project.version}</version>
+		</dependency>
+
+		<dependency>
+			<groupId>org.springframework.boot</groupId>
+			<artifactId>spring-boot-test</artifactId>
+			<scope>test</scope>
+		</dependency>
+		<dependency>
+			<groupId>org.junit.vintage</groupId>
+			<artifactId>junit-vintage-engine</artifactId>
+			<scope>test</scope>
+		</dependency>
+	</dependencies>
+
+	<build>
+		<plugins>
+			<plugin>
+				<groupId>org.apache.maven.plugins</groupId>
+				<artifactId>maven-deploy-plugin</artifactId>
+				<configuration>
+					<!--test module only - should not be deployed -->
+					<skip>true</skip>
+				</configuration>
+			</plugin>
+			<plugin>
+				<groupId>org.apache.maven.plugins</groupId>
+				<artifactId>maven-enforcer-plugin</artifactId>
+				<executions>
+					<execution>
+						<id>enforce-banned-dependencies</id>
+						<goals>
+							<goal>enforce</goal>
+						</goals>
+						<configuration>
+							<rules>
+								<bannedDependencies>
+									<excludes>
+										<exclude>org.springframework.retry:spring-retry</exclude>
+									</excludes>
+								</bannedDependencies>
+							</rules>
+							<fail>true</fail>
+						</configuration>
+					</execution>
+				</executions>
+			</plugin>
+		</plugins>
+	</build>
+</project>

spring-cloud-vault-config-tests/src/test/java/org/springframework/cloud/vault/config/VaultAutoConfigurationRetryUnavailableTests.java

@@ -0,0 +1,54 @@
+/*
+ * Copyright 2016-2020 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.cloud.vault.config;
+
+import org.junit.Test;
+import org.springframework.boot.autoconfigure.AutoConfigurations;
+import org.springframework.boot.test.context.runner.ApplicationContextRunner;
+import org.springframework.http.HttpMethod;
+import org.springframework.http.client.ClientHttpRequest;
+import org.springframework.http.client.ClientHttpRequestFactory;
+import org.springframework.vault.config.AbstractVaultConfiguration;
+
+import java.net.URI;
+
+import static org.assertj.core.api.AssertionsForClassTypes.assertThat;
+
+/**
+ * Tests without spring-retry on the classpath to be sure there is no hard dependency
+ */
+public class VaultAutoConfigurationRetryUnavailableTests {
+
+	private ApplicationContextRunner contextRunner = new ApplicationContextRunner()
+			.withConfiguration(AutoConfigurations.of(VaultAutoConfiguration.class));
+
+	@Test
+	public void shouldNotBeConfigured() {
+
+		this.contextRunner.withPropertyValues("spring.cloud.vault.kv.enabled=false",
+				"spring.cloud.vault.fail-fast=true", "spring.cloud.vault.token=foo").run(context -> {
+					assertThat(context.containsBean("vaultRetryOperations")).isFalse();
+					AbstractVaultConfiguration.ClientFactoryWrapper clientFactoryWrapper = context
+							.getBean(AbstractVaultConfiguration.ClientFactoryWrapper.class);
+					ClientHttpRequestFactory requestFactory = clientFactoryWrapper.getClientHttpRequestFactory();
+					ClientHttpRequest request = requestFactory.createRequest(new URI("https://spring.io/"),
+							HttpMethod.GET);
+					assertThat(request instanceof RetryableClientHttpRequest).isFalse();
+				});
+	}
+
+}

spring-cloud-vault-config/pom.xml

@@ -59,6 +59,12 @@
 			<optional>true</optional>
 		</dependency>
 
+		<dependency>
+			<groupId>org.springframework.retry</groupId>
+			<artifactId>spring-retry</artifactId>
+			<optional>true</optional>
+		</dependency>
+
 		<!-- HTTP Client Libraries -->
 		<dependency>
 			<groupId>org.apache.httpcomponents</groupId>

spring-cloud-vault-config/src/main/java/org/springframework/cloud/vault/config/RetryableClientHttpRequest.java

@@ -0,0 +1,67 @@
+/*
+ * Copyright 2016-2020 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.cloud.vault.config;
+
+import org.springframework.http.HttpHeaders;
+import org.springframework.http.client.ClientHttpRequest;
+import org.springframework.http.client.ClientHttpResponse;
+import org.springframework.retry.RetryOperations;
+
+import java.io.IOException;
+import java.io.OutputStream;
+import java.net.URI;
+
+/**
+ * {@link ClientHttpRequest} configured with retry support
+ */
+class RetryableClientHttpRequest implements ClientHttpRequest {
+
+	private final ClientHttpRequest delegateRequest;
+
+	private final RetryOperations retryOperations;
+
+	RetryableClientHttpRequest(ClientHttpRequest request, RetryOperations retryOperations) {
+		this.delegateRequest = request;
+		this.retryOperations = retryOperations;
+	}
+
+	@Override
+	public ClientHttpResponse execute() throws IOException {
+		return retryOperations.execute(retryContext -> delegateRequest.execute());
+	}
+
+	@Override
+	public OutputStream getBody() throws IOException {
+		return delegateRequest.getBody();
+	}
+
+	@Override
+	public String getMethodValue() {
+		return delegateRequest.getMethodValue();
+	}
+
+	@Override
+	public URI getURI() {
+		return delegateRequest.getURI();
+	}
+
+	@Override
+	public HttpHeaders getHeaders() {
+		return delegateRequest.getHeaders();
+	}
+
+}

spring-cloud-vault-config/src/main/java/org/springframework/cloud/vault/config/VaultAutoConfiguration.java

@@ -39,6 +39,7 @@
 import org.springframework.http.client.ClientHttpRequestFactory;
 import org.springframework.scheduling.TaskScheduler;
 import org.springframework.scheduling.concurrent.ThreadPoolTaskScheduler;
+import org.springframework.util.ClassUtils;
 import org.springframework.vault.authentication.ClientAuthentication;
 import org.springframework.vault.authentication.LifecycleAwareSessionManager;
 import org.springframework.vault.authentication.SessionManager;
@@ -129,7 +130,15 @@ protected RestTemplateBuilder restTemplateBuilder(ClientHttpRequestFactory reque
 	@Bean
 	@ConditionalOnMissingBean
 	public ClientFactoryWrapper clientHttpRequestFactoryWrapper() {
-		return new ClientFactoryWrapper(this.configuration.createClientHttpRequestFactory());
+		ClientHttpRequestFactory clientHttpRequestFactory;
+		if (ClassUtils.isPresent("org.springframework.retry.support.RetryTemplate", getClass().getClassLoader())
+				&& this.vaultProperties.isFailFast()) {
+			clientHttpRequestFactory = this.configuration.createRetryableClientHttpRequestFactory();
+		}
+		else {
+			clientHttpRequestFactory = this.configuration.createClientHttpRequestFactory();
+		}
+		return new ClientFactoryWrapper(clientHttpRequestFactory);
 	}
 
 	/**

spring-cloud-vault-config/src/main/java/org/springframework/cloud/vault/config/VaultConfiguration.java

@@ -111,6 +111,11 @@ ClientHttpRequestFactory createClientHttpRequestFactory() {
 		return ClientHttpRequestFactoryFactory.create(clientOptions, sslConfiguration);
 	}
 
+	public ClientHttpRequestFactory createRetryableClientHttpRequestFactory() {
+		ClientHttpRequestFactory delegate = createClientHttpRequestFactory();
+		return VaultRetryUtil.createRetryableClientHttpRequestFactory(this.vaultProperties, delegate);
+	}
+
 	/**
 	 * Create a {@link VaultEndpoint} from {@link VaultProperties}.
 	 * @return the endpoint.

spring-cloud-vault-config/src/main/java/org/springframework/cloud/vault/config/VaultProperties.java

@@ -130,6 +130,8 @@ public class VaultProperties implements EnvironmentAware {
 
 	private Session session = new Session();
 
+	private Retry retry = new Retry();
+
 	/**
 	 * Application name for AppId authentication.
 	 */
@@ -350,6 +352,14 @@ public void setAuthentication(AuthenticationMethod authentication) {
 		this.authentication = authentication;
 	}
 
+	public Retry getRetry() {
+		return this.retry;
+	}
+
+	public void setRetry(Retry retry) {
+		this.retry = retry;
+	}
+
 	/**
 	 * Enumeration of authentication methods.
 	 */
@@ -1287,4 +1297,65 @@ public void setExpiryThreshold(Duration expiryThreshold) {
 
 	}
 
+	/**
+	 * Vault retry configuration
+	 *
+	 * @since 3.0.2
+	 */
+	public static class Retry {
+
+		/**
+		 * Initial retry interval in milliseconds.
+		 */
+		long initialInterval = 1000;
+
+		/**
+		 * Multiplier for next interval.
+		 */
+		double multiplier = 1.1;
+
+		/**
+		 * Maximum interval for backoff.
+		 */
+		long maxInterval = 2000;
+
+		/**
+		 * Maximum number of attempts.
+		 */
+		int maxAttempts = 6;
+
+		public long getInitialInterval() {
+			return this.initialInterval;
+		}
+
+		public void setInitialInterval(long initialInterval) {
+			this.initialInterval = initialInterval;
+		}
+
+		public double getMultiplier() {
+			return this.multiplier;
+		}
+
+		public void setMultiplier(double multiplier) {
+			this.multiplier = multiplier;
+		}
+
+		public long getMaxInterval() {
+			return this.maxInterval;
+		}
+
+		public void setMaxInterval(long maxInterval) {
+			this.maxInterval = maxInterval;
+		}
+
+		public int getMaxAttempts() {
+			return this.maxAttempts;
+		}
+
+		public void setMaxAttempts(int maxAttempts) {
+			this.maxAttempts = maxAttempts;
+		}
+
+	}
+
 }

spring-cloud-vault-config/src/main/java/org/springframework/cloud/vault/config/VaultRetryUtil.java

@@ -0,0 +1,53 @@
+/*
+ * Copyright 2018-2020 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.cloud.vault.config;
+
+import org.springframework.http.client.ClientHttpRequest;
+import org.springframework.http.client.ClientHttpRequestFactory;
+import org.springframework.retry.backoff.ExponentialBackOffPolicy;
+import org.springframework.retry.policy.SimpleRetryPolicy;
+import org.springframework.retry.support.RetryTemplate;
+
+/**
+ * Util class for building objects that rely on spring-retry
+ */
+final class VaultRetryUtil {
+
+	private VaultRetryUtil() {
+
+	}
+
+	static ClientHttpRequestFactory createRetryableClientHttpRequestFactory(VaultProperties vaultProperties,
+			ClientHttpRequestFactory delegate) {
+		VaultProperties.Retry retryProperties = vaultProperties.getRetry();
+		RetryTemplate retryTemplate = new RetryTemplate();
+
+		ExponentialBackOffPolicy policy = new ExponentialBackOffPolicy();
+		policy.setInitialInterval(retryProperties.getInitialInterval());
+		policy.setMultiplier(retryProperties.getMultiplier());
+		policy.setMaxInterval(retryProperties.getMaxInterval());
+
+		retryTemplate.setBackOffPolicy(policy);
+		retryTemplate.setRetryPolicy(new SimpleRetryPolicy(retryProperties.getMaxAttempts()));
+
+		return (uri, httpMethod) -> retryTemplate.execute(retryContext -> {
+			ClientHttpRequest request = delegate.createRequest(uri, httpMethod);
+			return new RetryableClientHttpRequest(request, retryTemplate);
+		});
+	}
+
+}