Add fail-fast option.

Fixes gh-3.

src/main/java/org/springframework/cloud/vault/VaultClient.java

@@ -16,6 +16,8 @@
 
 package org.springframework.cloud.vault;
 
+import static com.sun.org.apache.xalan.internal.xsltc.compiler.sym.error;
+
 import java.util.Collections;
 import java.util.HashMap;
 import java.util.Map;
@@ -24,11 +26,13 @@ import lombok.RequiredArgsConstructor;
 import lombok.Setter;
 import lombok.Value;
 
+import lombok.extern.apachecommons.CommonsLog;
 import org.springframework.cloud.vault.VaultProperties.AppIdProperties;
 import org.springframework.cloud.vault.VaultProperties.AuthenticationMethod;
 import org.springframework.http.*;
 import org.springframework.util.Assert;
 import org.springframework.web.client.HttpClientErrorException;
+import org.springframework.web.client.HttpServerErrorException;
 import org.springframework.web.client.HttpStatusCodeException;
 import org.springframework.web.client.RestTemplate;
 
@@ -40,6 +44,7 @@ import org.springframework.web.client.RestTemplate;
  * @author Mark Paluch
  */
 @RequiredArgsConstructor
+@CommonsLog
 public class VaultClient {
 
 	public static final String API_VERSION = "v1";
@@ -61,6 +66,10 @@ public class VaultClient {
 		String url = buildUrl();
 
 		HttpHeaders headers = createHeaders(vaultToken);
+		Exception error = null;
+		String errorBody = null;
+
+		log.info(String.format("Fetching config from server at: %s", url));
 		try {
 			ResponseEntity<VaultResponse> response = this.rest.exchange(url,
 					HttpMethod.GET, new HttpEntity<>(headers), VaultResponse.class,
@@ -68,16 +77,30 @@ public class VaultClient {
 
 			HttpStatus status = response.getStatusCode();
 			if (status == HttpStatus.OK) {
-				if(response.getBody().getData() != null){
+				if (response.getBody().getData() != null) {
 					return secureBackendAccessor.transformProperties(response.getBody().getData());
 				}
 			}
-		} catch (HttpStatusCodeException e) {
-			if (e.getStatusCode() == HttpStatus.NOT_FOUND) {
-				return null;
-			}
-			throw e;
 		}
+		catch (HttpServerErrorException e) {
+			error = e;
+			if (MediaType.APPLICATION_JSON.includes(e.getResponseHeaders()
+					.getContentType())) {
+				errorBody = e.getResponseBodyAsString();
+			}
+		}
+		catch (Exception e) {
+			error = e;
+		}
+
+		if (properties.isFailFast()) {
+			throw new IllegalStateException(
+					"Could not locate PropertySource and the fail fast property is set, failing",
+					error);
+		}
+
+		log.warn(String.format("Could not locate PropertySource: %s"
+				, (errorBody == null ? error==null ? "key not found" : error.getMessage() : errorBody)));
 
 		return Collections.emptyMap();
 	}

src/main/java/org/springframework/cloud/vault/VaultProperties.java

@@ -70,6 +70,11 @@ public class VaultProperties {
 	@NotEmpty
 	private String profileSeparator = ",";
 
+	/**
+	 * Fail fast if data cannot be obtained from Vault.
+	 */
+	private boolean failFast = false;
+
 	/**
 	 * Static vault token. Required if {@link #authentication} is {@code TOKEN}.
 	 */

src/main/java/org/springframework/cloud/vault/VaultPropertySource.java

@@ -18,13 +18,13 @@ package org.springframework.cloud.vault;
 
 import java.util.*;
 
-import lombok.extern.apachecommons.CommonsLog;
-
 import org.springframework.cloud.vault.VaultProperties.AppIdProperties;
 import org.springframework.cloud.vault.VaultProperties.AuthenticationMethod;
 import org.springframework.core.env.EnumerablePropertySource;
 import org.springframework.util.Assert;
 
+import lombok.extern.apachecommons.CommonsLog;
+
 /**
  * @author Spencer Gibb
  * @author Mark Paluch
@@ -36,10 +36,11 @@ public class VaultPropertySource extends EnumerablePropertySource<VaultClient> {
 
 	private String context;
 	private Map<String, String> properties = new LinkedHashMap<>();
-	
+
 	private transient VaultState vaultState;
 
-	public VaultPropertySource(String context, VaultClient source, VaultProperties properties, VaultState state) {
+	public VaultPropertySource(String context, VaultClient source,
+			VaultProperties properties, VaultState state) {
 		super(context, source);
 		this.context = context;
 		this.vaultProperties = properties;
@@ -62,8 +63,19 @@ public class VaultPropertySource extends EnumerablePropertySource<VaultClient> {
 				}
 			}
 			catch (Exception e) {
-				log.error(String.format("Unable to read properties from vault for %s ",
-						accessor.variables()), e);
+
+				String message = String.format(
+						"Unable to read properties from vault for %s ",
+						accessor.variables());
+				if (vaultProperties.isFailFast()) {
+					if (e instanceof RuntimeException) {
+						throw e;
+					}
+
+					throw new IllegalStateException(message, e);
+				}
+
+				log.error(message, e);
 			}
 		}
 	}
@@ -76,17 +88,17 @@ public class VaultPropertySource extends EnumerablePropertySource<VaultClient> {
 				this.context));
 
 		VaultProperties.MySql mySql = vaultProperties.getMysql();
-		if(mySql.isEnabled()){
+		if (mySql.isEnabled()) {
 			accessors.add(SecureBackendAccessors.database(mySql));
 		}
 
 		VaultProperties.PostgreSql postgreSql = vaultProperties.getPostgresql();
-		if(postgreSql.isEnabled()){
+		if (postgreSql.isEnabled()) {
 			accessors.add(SecureBackendAccessors.database(postgreSql));
 		}
 
 		VaultProperties.Cassandra cassandra = vaultProperties.getCassandra();
-		if(cassandra.isEnabled()){
+		if (cassandra.isEnabled()) {
 			accessors.add(SecureBackendAccessors.database(cassandra));
 		}
 		return accessors;

src/test/java/org/springframework/cloud/vault/GenericSecretIntegrationTests.java

@@ -29,6 +29,7 @@ import org.springframework.web.client.RestTemplate;
 
 /**
  * Integration tests for {@link VaultClient} using the generic secret backend.
+ *
  * @author Mark Paluch
  */
 public class GenericSecretIntegrationTests extends AbstractIntegrationTests {
@@ -39,6 +40,7 @@ public class GenericSecretIntegrationTests extends AbstractIntegrationTests {
 	@Before
 	public void setUp() throws Exception {
 
+		vaultProperties.setFailFast(false);
 		prepare().writeSecret("app-name", (Map) createData());
 		vaultClient.setRest(new RestTemplate());
 	}
@@ -55,6 +57,17 @@ public class GenericSecretIntegrationTests extends AbstractIntegrationTests {
 	@Test
 	public void shouldReturnNullIfNotFound() throws Exception {
 
+		Map<String, String> secretProperties = vaultClient
+				.read(generic(vaultProperties, "missing"), createToken());
+
+		assertThat(secretProperties).isEmpty();
+	}
+
+	@Test(expected = IllegalStateException.class)
+	public void shouldFailOnFailFast() throws Exception {
+
+		vaultProperties.setFailFast(true);
+
 		Map<String, String> secretProperties = vaultClient
 				.read(generic(vaultProperties, "missing"), createToken());
 
@@ -85,5 +98,4 @@ public class GenericSecretIntegrationTests extends AbstractIntegrationTests {
 		data.put("boolean", "true");
 		return data;
 	}
-
 }

src/test/java/org/springframework/cloud/vault/configclient/ApplicationFailFastTests.java

@@ -0,0 +1,46 @@
+/*
+ * Copyright 2016 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.cloud.vault.configclient;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.junit.Assert.fail;
+
+import org.junit.Test;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+import org.springframework.boot.builder.SpringApplicationBuilder;
+
+/**
+ * Tests for fail fast option.
+ *
+ * @author Mark Paluch
+ */
+@SpringBootApplication
+public class ApplicationFailFastTests {
+
+	@Test
+	public void contextLoads() {
+		try {
+			new SpringApplicationBuilder().sources(ApplicationFailFastTests.class).run(
+					"--server.port=0", "--spring.cloud.vault.failFast=true",
+					"--spring.cloud.vault.port=9999");
+			fail("failFast option did not produce an exception");
+		}
+		catch (Exception e) {
+			assertThat(e).hasMessageContaining("fail fast");
+		}
+	}
+}