gistfile1.py

policy = """{
  "Statement":[{
    "Effect":"Allow",
    "Action":["s3:*"],
    "Resource":["arn:aws:s3:::mybucket"]}]}"""
import boto
c = boto.connect_iam()
instance_profile = c.create_instance_profile('myinstanceprofile')
role = c.create_role('myrole')
c.add_role_to_instance_profile('myinstanceprofile', 'myrole')
{u'add_role_to_instance_profile_response': {u'response_metadata': {u'request_id': u'2221d92c-b437-11e1-86e5-c9c4f3b58653'}}}
c.put_role_policy('myrole', 'mypolicy', policy)
{u'put_role_policy_response': {u'response_metadata': {u'request_id': u'2b878c93-b437-11e1-86e5-c9c4f3b58653'}}}
c = boto.connect_ec2()
 c.run_instances('ami-e565ba8c', key_name='mykeyname', security_groups=['mysecuritygroup'], instance_type='t1.micro', instance_profile_name='myinstanceprofile')