add ecs ram role provider.

Author: huiguangjun

src/main/java/com/aliyun/oss/common/auth/EcsRamRoleCredentialsFetcher.java

@@ -0,0 +1,85 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you 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 com.aliyun.oss.common.auth;
+
+import java.net.MalformedURLException;
+import java.net.URL;
+
+import com.aliyun.oss.common.auth.Credentials;
+import com.aliyun.oss.common.utils.AuthUtils;
+import com.aliyuncs.exceptions.ClientException;
+import com.aliyuncs.http.HttpResponse;
+import org.codehaus.jettison.json.JSONException;
+import org.codehaus.jettison.json.JSONObject;
+
+public class EcsRamRoleCredentialsFetcher extends HttpCredentialsFetcher {
+
+    public EcsRamRoleCredentialsFetcher(String ossAuthServerHost) {
+        this.ossAuthServerHost = ossAuthServerHost;
+    }
+
+    @Override
+    public URL buildUrl() throws ClientException {
+        try {
+            return new URL(ossAuthServerHost);
+        } catch (MalformedURLException e) {
+            throw new IllegalArgumentException(e.toString());
+        }
+    }
+
+    public Credentials parse(HttpResponse response) throws ClientException {
+        String jsonContent = new String(response.getHttpContent());
+
+        try {
+            JSONObject jsonObject = new JSONObject(jsonContent);
+
+            if (!jsonObject.has("Code")) {
+                throw new ClientException("Invalid json " + jsonContent + " got from ecs metadata server.");
+            }
+
+            if (!"Success".equals(jsonObject.get("Code"))) {
+                throw new ClientException("Failed to get credentials from ecs metadata server");
+            }
+
+            if (!jsonObject.has("AccessKeyId") || !jsonObject.has("AccessKeySecret")) {
+                throw new ClientException("Invalid json " + jsonContent + " got from ecs metadata server.");
+            }
+
+            String securityToken = null;
+            if (jsonObject.has("SecurityToken")) {
+                securityToken = jsonObject.getString("SecurityToken");
+            }
+
+            if (jsonObject.has("Expiration")) {
+                return new InstanceProfileCredentials(jsonObject.getString("AccessKeyId"),
+                        jsonObject.getString("AccessKeySecret"), securityToken, jsonObject.getString("Expiration"))
+                                .withExpiredDuration(
+                                        AuthUtils.DEFAULT_STS_SESSION_TOKEN_DURATION_SECONDS);
+            }
+
+            return new BasicCredentials(jsonObject.getString("AccessKeyId"), jsonObject.getString("AccessKeySecret"),
+                    securityToken);
+        } catch (JSONException e) {
+            throw new ClientException("EcsRamRoleCredentialsFetcher.parse [" + jsonContent + "] exception:" + e);
+        }
+    }
+
+    private String ossAuthServerHost;
+}

src/main/java/com/aliyun/oss/common/auth/EcsRamRoleCredentialsProvider.java

@@ -0,0 +1,60 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you 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 com.aliyun.oss.common.auth;
+
+import com.aliyun.oss.common.utils.AuthUtils;
+import com.aliyun.oss.common.utils.LogUtils;
+import com.aliyuncs.exceptions.ClientException;
+
+public class EcsRamRoleCredentialsProvider implements CredentialsProvider {
+
+    public EcsRamRoleCredentialsProvider(String ossAuthServerHost) {
+        this.fetcher = new EcsRamRoleCredentialsFetcher(ossAuthServerHost);
+    }
+    
+    public EcsRamRoleCredentialsProvider withCredentialsFetcher(EcsRamRoleCredentialsFetcher fetcher) {
+        this.fetcher = fetcher;
+        return this;
+    }
+
+    @Override
+    public void setCredentials(Credentials creds) {
+
+    }
+
+    @Override
+    public Credentials getCredentials() {        
+        if (credentials == null || credentials.willSoonExpire()) {
+            try {
+                credentials = (BasicCredentials) fetcher.fetch(maxRetryTimes);
+            } catch (ClientException e) {
+                LogUtils.logException("EcsRoleCredentialsProvider.fetch Exception:", e);
+                return null;
+            }
+        }
+        return credentials;
+    }
+
+    private BasicCredentials credentials;
+    private EcsRamRoleCredentialsFetcher fetcher;
+
+    private int maxRetryTimes = AuthUtils.MAX_ECS_METADATA_FETCH_RETRY_TIMES;
+
+}