Running jobs using EMR cluster and s3 files from other account

Question

I would like to know if there is a way to access jar files and input and output location from s3 of another account. I have my EMR cluster running on account 1. I want to access File and jar locations from s3 of account 2. I am using AWS SDK to launch AWS Simple workflow. Thanks.

Answer 1

You need to create role for cross-account access: http://docs.aws.amazon.com/IAM/latest/UserGuide/delegation-cross-acct-access.html

You can establish cross-account access by using IAM roles. You define a role in Account 2 that can be assumed by a user (an IAM user or a federated user) in Account 1. Using roles for cross-account access lets you grant access to any resource in Account 2 (in your case it is S3)

EDIT:

You need first to create a Role with readwrite access to S3 in Account 2 (let's name it "S3-ReadWrite-role"), and give permission to users from Account 1 to use the role "S3-ReadWrite-role"

Check this link,it will explain to you how to do it: http://blogs.aws.amazon.com/security/post/TxC24FI9IDXTY1/Delegating-API-Access-to-AWS-Services-Using-IAM-span-class-matches-Roles-span

After you finish the fist step, you can use this code ( not tested): Using your credentials, you'll receive a temporary security credentials to use "S3-ReadWrite-role", then you'll use the temporary security credentials to access to S3 ;)

import java.util.HashMap;

import com.amazonaws.services.securitytoken.AWSSecurityTokenServiceClient;
import com.amazonaws.services.securitytoken.model.AssumeRoleRequest;
import com.amazonaws.services.securitytoken.model.AssumeRoleResult;
import com.amazonaws.services.dynamodb.AmazonDynamoDBClient;
import com.amazonaws.services.dynamodb.model.*;
import com.amazonaws.auth.*;

public class AssumeRoleDemo {
    private static final String ROLE_ARN =
    "arn:aws:iam::111122223333:role/S3-ReadWrite-role";

    private static AWSCredentials longTermCredentials_;

    private static void init() throws Exception {
    // acquire long term credentials from the properties file ( you should use this method)
    //longTermCredentials_ = new PropertiesCredentials(AssumeRoleDemo.class.getResourceAsStream("AwsCredentials.properties"));

    // or you can use this one
    longTermCredentials = new BasicAWSCredentials(access_key_id, secret_access_key);
}

    public static void main(String[] args) throws Exception {
        init();

       // Step 1. Use Joe.s long-term credentials to call the
       // AWS Security Token Service (STS) AssumeRole API, specifying 
       // the ARN for the role S3-RW-role in account2.

        AWSSecurityTokenServiceClient stsClient = new
          AWSSecurityTokenServiceClient(longTermCredentials_);

        AssumeRoleRequest assumeRequest = new AssumeRoleRequest()
          .withRoleArn(ROLE_ARN)
          .withDurationSeconds(3600)
          .withRoleSessionName("demo");

       AssumeRoleResult assumeResult =
           stsClient.assumeRole(assumeRequest);

      // Step 2. AssumeRole returns temporary security credentials for 
      // the IAM role.

      BasicSessionCredentials temporaryCredentials =
         new BasicSessionCredentials(
                assumeResult.getCredentials().getAccessKeyId(),
                assumeResult.getCredentials().getSecretAccessKey(),
                assumeResult.getCredentials().getSessionToken());

     // Step 3. Make S3 service calls to read data from a 
     // S3, stored in account2, using the 
     // temporary security credentials from the S3-ReadWrite-role 
     // that were returned in the previous step.

     AmazonS3 s3Client = new AmazonS3Client(temporaryCredentials);
     S3Object object = s3Client.getObject(
              new GetObjectRequest(bucketName, key));
     InputStream objectData = object.getObjectContent();
     // Process the objectData stream.
     objectData.close();

    }
}