Add configuration to retry lease renewal on error.

Closes gh-708

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

@@ -45,6 +45,7 @@ import org.springframework.vault.client.VaultHttpHeaders;
 import org.springframework.vault.core.VaultOperations;
 import org.springframework.vault.core.lease.SecretLeaseContainer;
 import org.springframework.vault.support.ClientOptions;
+import org.springframework.vault.support.LeaseStrategy;
 import org.springframework.vault.support.SslConfiguration;
 import org.springframework.vault.support.SslConfiguration.KeyStoreConfiguration;
 import org.springframework.web.client.RestTemplate;
@@ -222,6 +223,15 @@ final class VaultConfiguration {
 			if (lifecycle.getLeaseEndpoints() != null) {
 				container.setLeaseEndpoints(lifecycle.getLeaseEndpoints());
 			}
+
+			if (lifecycle.getLeaseStrategy() != null) {
+
+				switch (lifecycle.getLeaseStrategy()) {
+					case DropOnError -> container.setLeaseStrategy(LeaseStrategy.dropOnError());
+					case RetainOnError -> container.setLeaseStrategy(LeaseStrategy.retainOnError());
+					case RetainOnIoError -> container.setLeaseStrategy(LeaseStrategy.retainOnIoError());
+				}
+			}
 		}
 	}
 

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

@@ -31,6 +31,7 @@ import org.springframework.util.StringUtils;
 import org.springframework.vault.authentication.AzureMsiAuthenticationOptions;
 import org.springframework.vault.authentication.LoginToken;
 import org.springframework.vault.core.lease.LeaseEndpoints;
+import org.springframework.vault.support.LeaseStrategy;
 
 /**
  * Properties to configure Vault support.
@@ -1252,12 +1253,20 @@ public class VaultProperties implements EnvironmentAware {
 		 *
 		 * Can be {@link LeaseEndpoints#SysLeases} for version 0.8 or above of Vault or
 		 * {@link LeaseEndpoints#Legacy} for older versions (the default).
-		 *
 		 * @since 2.2
 		 */
 		@Nullable
 		private LeaseEndpoints leaseEndpoints;
 
+		/**
+		 * Sets the {@link LeaseStrategy} to be used with
+		 * {@link org.springframework.vault.core.lease.SecretLeaseContainer#setLeaseStrategy(LeaseStrategy)}
+		 * to retain or drop tokens on renewal errors.
+		 * @since 4.1
+		 */
+		@Nullable
+		private PredefinedLeaseStrategy leaseStrategy;
+
 		public boolean isEnabled() {
 			return this.enabled;
 		}
@@ -1293,6 +1302,25 @@ public class VaultProperties implements EnvironmentAware {
 			this.leaseEndpoints = leaseEndpoints;
 		}
 
+		@Nullable
+		public PredefinedLeaseStrategy getLeaseStrategy() {
+			return this.leaseStrategy;
+		}
+
+		public void setLeaseStrategy(@Nullable PredefinedLeaseStrategy leaseStrategy) {
+			this.leaseStrategy = leaseStrategy;
+		}
+
+	}
+
+	/**
+	 * @since 4.1
+	 * @see LeaseStrategy
+	 */
+	enum PredefinedLeaseStrategy {
+
+		RetainOnError, RetainOnIoError, DropOnError,
+
 	}
 
 	/**

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

@@ -29,6 +29,7 @@ import org.springframework.scheduling.concurrent.ThreadPoolTaskScheduler;
 import org.springframework.vault.core.VaultOperations;
 import org.springframework.vault.core.lease.LeaseEndpoints;
 import org.springframework.vault.core.lease.SecretLeaseContainer;
+import org.springframework.vault.support.LeaseStrategy;
 
 import static org.mockito.Mockito.mock;
 import static org.mockito.Mockito.verify;
@@ -45,13 +46,14 @@ public class VaultBootstrapPropertySourceConfigurationTests {
 			.withConfiguration(AutoConfigurations.of(VaultBootstrapPropertySourceConfiguration.class));
 
 	@Test
-	public void shouldConfigureExpiryTimeouts() {
+	public void shouldConfigureExpiryTimeoutsAndStrategy() {
 
 		this.contextRunner.withUserConfiguration(MockConfiguration.class).withAllowBeanDefinitionOverriding(true)
 				.withPropertyValues("spring.cloud.vault.kv.enabled=false",
 						"spring.cloud.vault.config.lifecycle.expiry-threshold=5m",
 						"spring.cloud.vault.config.lifecycle.min-renewal=6m",
 						"spring.cloud.vault.config.lifecycle.lease-endpoints=Leases",
+						"spring.cloud.vault.config.lifecycle.lease-strategy=retain-on-error",
 						"spring.cloud.bootstrap.enabled=true")
 				.run(context -> {
 
@@ -59,6 +61,7 @@ public class VaultBootstrapPropertySourceConfigurationTests {
 					verify(container).setExpiryThreshold(Duration.ofMinutes(5));
 					verify(container).setMinRenewal(Duration.ofMinutes(6));
 					verify(container).setLeaseEndpoints(LeaseEndpoints.Leases);
+					verify(container).setLeaseStrategy(LeaseStrategy.retainOnError());
 				});
 	}