Added the ability to add volumes to instances at creation time

This allows a volume to be cloned from a snapshot, a brand new
volume to be created, or an ephemeral volumes to be associated
at time of instance creation.

This avoids any race conditions associated with creating extra volumes
after instance creation (e.g. writes happening before the volume is
mounted).

In addition, this allows the root volume to be edited

library/cloud/ec2

@@ -191,6 +191,13 @@ options:
     required: false
     default: 'present'
     aliases: []
+  volumes:
+    version_added: "1.5"
+    description:
+      - a list of volume dicts, each containing device name and optionally ephemeral id or snapshot id. Size and type (and number of iops for io device type) must be specified for a new volume or a root volume, and may be passed for a snapshot volume. For any volume, a volume size less than 1 will be interpreted as a request not to create the volume.
+    required: false
+    default: null
+    aliases: []
 
 requirements: [ "boto" ]
 author: Seth Vidal, Tim Gerla, Lester Wade
@@ -223,6 +230,23 @@ EXAMPLES = '''
     instance_tags: '{"db":"postgres"}'
     monitoring=yes
 
+# Single instance with additional IOPS volume from snapshot
+local_action:
+    module: ec2
+    keypair: mykey
+    group: webserver
+    instance_type: m1.large
+    image: ami-6e649707
+    wait: yes
+    wait_timeout: 500
+    volumes:
+    - device_name: /dev/sdb
+      snapshot: snap-abcdef12
+      device_type: io1
+      iops: 1000
+      volume_size: 100
+    monitoring=yes
+
 # Multiple groups example
 local_action:
     module: ec2
@@ -236,6 +260,22 @@ local_action:
     instance_tags: '{"db":"postgres"}'
     monitoring=yes
 
+# Multiple instances with additional volume from snapshot
+local_action:
+    module: ec2
+    keypair: mykey
+    group: webserver
+    instance_type: m1.large
+    image: ami-6e649707
+    wait: yes
+    wait_timeout: 500
+    count: 5
+    volumes:
+    - device_name: /dev/sdb
+      snapshot: snap-abcdef12
+      volume_size: 10
+    monitoring=yes
+
 # VPC example
 - local_action:
     module: ec2
@@ -296,6 +336,7 @@ import time
 
 try:
     import boto.ec2
+    from boto.ec2.blockdevicemapping import BlockDeviceType, BlockDeviceMapping
     from boto.exception import EC2ResponseError
 except ImportError:
     print "failed=True msg='boto required for this module'"
@@ -364,6 +405,30 @@ def boto_supports_profile_name_arg(ec2):
     run_instances_method = getattr(ec2, 'run_instances')
     return 'instance_profile_name' in run_instances_method.func_code.co_varnames
 
+def create_block_device(module, ec2, volume):
+    # Not aware of a way to determine this programatically
+    # http://aws.amazon.com/about-aws/whats-new/2013/10/09/ebs-provisioned-iops-maximum-iops-gb-ratio-increased-to-30-1/
+    MAX_IOPS_TO_SIZE_RATIO = 30
+    if 'snapshot' not in volume and 'ephemeral' not in volume:
+        if 'volume_size' not in volume: 
+            module.fail_json(msg = 'Size must be specified when creating a new volume or modifying the root volume')
+    if 'snapshot' in volume:
+        if 'device_type' in volume and volume.get('device_type') == 'io1' and 'iops' not in volume:
+            module.fail_json(msg = 'io1 volumes must have an iops value set')
+        if 'iops' in volume:
+            snapshot = ec2.get_all_snapshots(snapshot_ids=[volume['snapshot']])[0]
+            size = volume.get('volume_size', snapshot.volume_size)
+            if int(volume['iops']) > MAX_IOPS_TO_SIZE_RATIO * size:
+                module.fail_json(msg = 'IOPS must be at most %d times greater than size' % MAX_IOPS_TO_SIZE_RATIO)
+    if 'ephemeral' in volume:
+        if 'snapshot' in volume: 
+            module.fail_json(msg = 'Cannot set both ephemeral and snapshot')
+    return BlockDeviceType(snapshot_id=volume.get('snapshot'),
+                           ephemeral_name=volume.get('ephemeral'),
+                           size=volume.get('volume_size'),
+                           volume_type=volume.get('device_type'),
+                           delete_on_termination=volume.get('delete_on_termination', False),
+                           iops=volume.get('iops'))
 
 def create_instances(module, ec2):
     """
@@ -397,6 +462,7 @@ def create_instances(module, ec2):
     assign_public_ip = module.boolean(module.params.get('assign_public_ip'))
     private_ip = module.params.get('private_ip')
     instance_profile_name = module.params.get('instance_profile_name')
+    volumes = module.params.get('volumes')
 
     # group_id and group_name are exclusive of each other
     if group_id and group_name:
@@ -489,6 +555,18 @@ def create_instances(module, ec2):
                 else:
                     params['security_groups'] = group_name
 
+            if volumes:
+                bdm = BlockDeviceMapping()
+                for volume in volumes: 
+                    if 'device_name' not in volume:
+                        module.fail_json(msg = 'Device name must be set for volume')
+                    # Minimum volume size is 1GB. We'll use volume size explicitly set to 0
+                    # to be a signal not to create this volume 
+                    if 'volume_size' not in volume or int(volume['volume_size']) > 0:
+                        bdm[volume['device_name']] = create_block_device(module, ec2, volume)
+
+                params['block_device_map'] = bdm
+
             res = ec2.run_instances(**params)
         except boto.exception.BotoServerError, e:
             module.fail_json(msg = "%s: %s" % (e.error_code, e.error_message))
@@ -641,6 +719,7 @@ def main():
             instance_profile_name = dict(),
             instance_ids = dict(type='list'),
             state = dict(default='present'),
+            volumes = dict(type='list'),
         )
     )