1 /*
2 * Copyright 2013-2019 the original author or authors.
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * https://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17 package org.springframework.cloud.aws.core.io.s3;
18
19 import com.amazonaws.regions.Regions;
20 import com.amazonaws.services.s3.AmazonS3;
21 import com.amazonaws.services.s3.model.AmazonS3Exception;
22 import org.aopalliance.intercept.MethodInterceptor;
23 import org.aopalliance.intercept.MethodInvocation;
24 import org.slf4j.Logger;
25 import org.slf4j.LoggerFactory;
26
27 import org.springframework.aop.Advisor;
28 import org.springframework.aop.framework.Advised;
29 import org.springframework.aop.framework.ProxyFactory;
30 import org.springframework.aop.support.AopUtils;
31 import org.springframework.util.Assert;
32 import org.springframework.util.ClassUtils;
33 import org.springframework.util.ReflectionUtils;
34
35 /**
36 * Proxy to wrap an {@link AmazonS3} handler and handle redirects wrapped inside
37 * {@link AmazonS3Exception}.
38 *
39 * @author Greg Turnquist
40 * @author Agim Emruli
41 * @since 1.1
42 */
43 public final class AmazonS3ProxyFactory {
44
45 private AmazonS3ProxyFactory() {
46 throw new IllegalStateException("Can't instantiate a utility class");
47 }
48
49 /**
50 * Factory-method to create a proxy using the {@link SimpleStorageRedirectInterceptor}
51 * that supports redirects for buckets which are in a different region. This proxy
52 * uses the amazonS3 parameter as a "prototype" and re-uses the credentials from the
53 * passed in {@link AmazonS3} instance. Proxy implementations uses the
54 * {@link AmazonS3ClientFactory} to create region specific clients, which are cached
55 * by the implementation on a region basis to avoid unnecessary object creation.
56 * @param amazonS3 Fully configured AmazonS3 client, the client can be an immutable
57 * instance (created by the {@link com.amazonaws.services.s3.AmazonS3ClientBuilder})
58 * as this proxy will not change the underlying implementation.
59 * @return AOP-Proxy that intercepts all method calls using the
60 * {@link SimpleStorageRedirectInterceptor}
61 */
62 public static AmazonS3 createProxy(AmazonS3 amazonS3) {
63 Assert.notNull(amazonS3, "AmazonS3 client must not be null");
64
65 if (AopUtils.isAopProxy(amazonS3)) {
66
67 Advised advised = (Advised) amazonS3;
68 for (Advisor advisor : advised.getAdvisors()) {
69 if (ClassUtils.isAssignableValue(SimpleStorageRedirectInterceptor.class,
70 advisor.getAdvice())) {
71 return amazonS3;
72 }
73 }
74
75 try {
76 advised.addAdvice(new SimpleStorageRedirectInterceptor(
77 (AmazonS3) advised.getTargetSource().getTarget()));
78 }
79 catch (Exception e) {
80 throw new RuntimeException(
81 "Error adding advice for class amazonS3 instance", e);
82 }
83
84 return amazonS3;
85 }
86
87 ProxyFactory factory = new ProxyFactory(amazonS3);
88 factory.setInterfaces(AmazonS3.class);
89 factory.addAdvice(new SimpleStorageRedirectInterceptor(amazonS3));
90
91 return (AmazonS3) factory.getProxy();
92 }
93
94 /**
95 * {@link MethodInterceptor} implementation that is handles redirect which are
96 * {@link AmazonS3Exception} with a return code of 301. This class creates a region
97 * specific client for the redirected endpoint.
98 *
99 * @author Greg Turnquist
100 * @author Agim Emruli
101 * @author André Caron
102 * @since 1.1
103 */
104 static final class SimpleStorageRedirectInterceptor implements MethodInterceptor {
105
106 private static final Logger LOGGER = LoggerFactory
107 .getLogger(SimpleStorageRedirectInterceptor.class);
108
109 private final AmazonS3 amazonS3;
110
111 private final AmazonS3ClientFactory amazonS3ClientFactory;
112
113 private SimpleStorageRedirectInterceptor(AmazonS3 amazonS3) {
114 this.amazonS3 = amazonS3;
115 this.amazonS3ClientFactory = new AmazonS3ClientFactory();
116 }
117
118 @Override
119 public Object invoke(MethodInvocation invocation) throws Throwable {
120 try {
121 return invocation.proceed();
122 }
123 catch (AmazonS3Exception e) {
124 if (301 == e.getStatusCode()) {
125 AmazonS3 redirectClient = buildAmazonS3ForRedirectLocation(
126 this.amazonS3, e);
127 return ReflectionUtils.invokeMethod(invocation.getMethod(),
128 redirectClient, invocation.getArguments());
129 }
130 else {
131 throw e;
132 }
133 }
134 }
135
136 /**
137 * Builds a new S3 client based on the information from the
138 * {@link AmazonS3Exception}. Extracts from the exception's additional details the
139 * region and endpoint of the bucket to be redirected to.
140 *
141 * Extracting the region from the exception is needed because the US S3 buckets
142 * don't always return an endpoint that includes the region and
143 * {@link AmazonS3ClientFactory} will default to us-west-2 if the hostname of the
144 * endpoint is "s3.amazonaws.com". The us-east-1 bucket is quite likely to return
145 * the "s3.amazonaws.com" endpoint.
146 */
147 private AmazonS3 buildAmazonS3ForRedirectLocation(AmazonS3 prototype,
148 AmazonS3Exception e) {
149 try {
150 Regions redirectRegion;
151 try {
152 redirectRegion = Regions.fromName(
153 e.getAdditionalDetails().get("x-amz-bucket-region"));
154 }
155 catch (IllegalArgumentException iae) {
156 redirectRegion = null;
157 }
158
159 return this.amazonS3ClientFactory.createClientForEndpointUrl(prototype,
160 "https://" + e.getAdditionalDetails().get("Endpoint"),
161 redirectRegion);
162 }
163 catch (Exception ex) {
164 LOGGER.error("Error getting new Amazon S3 for redirect", ex);
165 throw new RuntimeException(e);
166 }
167 }
168
169 }
170
171 }
172