[SOLVED] AWS CLI S3 A client error (403) occurred when calling the HeadObject operation: Forbidden

I'm trying to setup a Amazon Linux AMI(ami-f0091d91) and have a script that runs a copy command to copy from a S3 bucket.

aws --debug s3 cp s3://aws-codedeploy-us-west-2/latest/codedeploy-agent.noarch.rpm .

This script works perfectly on my local machine but fails with the following error on the Amazon Image:

2016-03-22 01:07:47,110 - MainThread - botocore.auth - DEBUG - StringToSign: HEAD

Tue, 22 Mar 2016 01:07:47 GMT
x-amz-security-token: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
/aws-codedeploy-us-west-2/latest/codedeploy-agent.noarch.rpm
2016-03-22 01:07:47,111 - MainThread - botocore.endpoint - DEBUG - Sending http request: <PreparedRequest [HEAD]>
2016-03-22 01:07:47,111 - MainThread - botocore.vendored.requests.packages.urllib3.connectionpool - INFO - Starting new HTTPS connection (1): aws-codedeploy-us-west-2.s3.amazonaws.com
2016-03-22 01:07:47,151 - MainThread - botocore.vendored.requests.packages.urllib3.connectionpool - DEBUG - "HEAD /latest/codedeploy-agent.noarch.rpm HTTP/1.1" 403 0
2016-03-22 01:07:47,151 - MainThread - botocore.parsers - DEBUG - Response headers: {'x-amz-id-2': '0mRvGge9ugu+KKyDmROm4jcTa1hAnA5Ax8vUlkKZXoJ//HVJAKxbpFHvOGaqiECa4sgon2F1kXw=', 'server': 'AmazonS3', 'transfer-encoding': 'chunked', 'x-amz-request-id': '6204CD88E880E5DD', 'date': 'Tue, 22 Mar 2016 01:07:46 GMT', 'content-type': 'application/xml'}
2016-03-22 01:07:47,152 - MainThread - botocore.parsers - DEBUG - Response body:

2016-03-22 01:07:47,152 - MainThread - botocore.hooks - DEBUG - Event needs-retry.s3.HeadObject: calling handler <botocore.retryhandler.RetryHandler object at 0x7f421075bcd0>
2016-03-22 01:07:47,152 - MainThread - botocore.retryhandler - DEBUG - No retry needed.
2016-03-22 01:07:47,152 - MainThread - botocore.hooks - DEBUG - Event after-call.s3.HeadObject: calling handler <function enhance_error_msg at 0x7f4211085758>
2016-03-22 01:07:47,152 - MainThread - botocore.hooks - DEBUG - Event after-call.s3.HeadObject: calling handler <awscli.errorhandler.ErrorHandler object at 0x7f421100cc90>
2016-03-22 01:07:47,152 - MainThread - awscli.errorhandler - DEBUG - HTTP Response Code: 403
2016-03-22 01:07:47,152 - MainThread - awscli.customizations.s3.s3handler - DEBUG - Exception caught during task execution: A client error (403) occurred when calling the HeadObject operation: Forbidden
Traceback (most recent call last):
  File "/usr/local/lib/python2.7/site-packages/awscli/customizations/s3/s3handler.py", line 100, in call
    total_files, total_parts = self._enqueue_tasks(files)
  File "/usr/local/lib/python2.7/site-packages/awscli/customizations/s3/s3handler.py", line 178, in _enqueue_tasks
    for filename in files:
  File "/usr/local/lib/python2.7/site-packages/awscli/customizations/s3/fileinfobuilder.py", line 31, in call
    for file_base in files:
  File "/usr/local/lib/python2.7/site-packages/awscli/customizations/s3/filegenerator.py", line 142, in call
    for src_path, extra_information in file_iterator:
  File "/usr/local/lib/python2.7/site-packages/awscli/customizations/s3/filegenerator.py", line 314, in list_objects
    yield self._list_single_object(s3_path)
  File "/usr/local/lib/python2.7/site-packages/awscli/customizations/s3/filegenerator.py", line 343, in _list_single_object
    response = self._client.head_object(**params)
  File "/usr/local/lib/python2.7/site-packages/botocore/client.py", line 228, in _api_call
    return self._make_api_call(operation_name, kwargs)
  File "/usr/local/lib/python2.7/site-packages/botocore/client.py", line 488, in _make_api_call
    model=operation_model, context=request_context
  File "/usr/local/lib/python2.7/site-packages/botocore/hooks.py", line 226, in emit
    return self._emit(event_name, kwargs)
  File "/usr/local/lib/python2.7/site-packages/botocore/hooks.py", line 209, in _emit
    response = handler(**kwargs)
  File "/usr/local/lib/python2.7/site-packages/awscli/errorhandler.py", line 70, in __call__
    http_status_code=http_response.status_code)
ClientError: A client error (403) occurred when calling the HeadObject operation: Forbidden
2016-03-22 01:07:47,153 - Thread-1 - awscli.customizations.s3.executor - DEBUG - Received print task: PrintTask(message='A client error (403) occurred when calling the HeadObject operation: Forbidden', error=True, total_parts=None, warning=None)
A client error (403) occurred when calling the HeadObject operation: Forbidden

However, when I run it with the --no-sign-request option, it works perfectly:

aws --debug --no-sign-request s3 cp s3://aws-codedeploy-us-west-2/latest/codedeploy-agent.noarch.rpm .

Can someone please explain what is going on?