switch to DefaultAWSCredentialsProviderChain which also includes Prof…

…ileCredentialsProvider, but also allows e.g. for AWS Instance Profile Roles and thus is more flexible and does not force developers to include credentials on their PredictionIO machines

storage/s3/src/main/scala/org/apache/predictionio/data/storage/s3/StorageClient.scala

@@ -17,21 +17,21 @@
 
 package org.apache.predictionio.data.storage.s3
 
+import com.amazonaws.auth.DefaultAWSCredentialsProviderChain
 import org.apache.predictionio.data.storage.BaseStorageClient
 import org.apache.predictionio.data.storage.StorageClientConfig
-
-import com.amazonaws.auth.profile.ProfileCredentialsProvider
 import com.amazonaws.client.builder.AwsClientBuilder
 import com.amazonaws.services.s3.AmazonS3
 import com.amazonaws.services.s3.AmazonS3ClientBuilder
-
 import grizzled.slf4j.Logging
 
 class StorageClient(val config: StorageClientConfig) extends BaseStorageClient
     with Logging {
   override val prefix = "S3"
   val client: AmazonS3 = {
-    val builder = AmazonS3ClientBuilder.standard().withCredentials(new ProfileCredentialsProvider())
+    val builder = AmazonS3ClientBuilder
+                    .standard()
+                    .withCredentials(DefaultAWSCredentialsProviderChain.getInstance())
     (config.properties.get("ENDPOINT"), config.properties.get("REGION")) match {
       case (Some(endpoint), Some(region)) =>
         builder.withEndpointConfiguration(new AwsClientBuilder.EndpointConfiguration(endpoint, region))