Enable ec2 volume types

At the moment we default to EBSBlockDevice, we need to be able to allow SSD
for example:

  prod:
    master_zone: domain.io
    ec2:
      block_devices:
      - DeviceName: /dev/sda1
        VolumeSize: 30
        VolumeType: gp2

(Closes # 160)

README.rst

@@ -162,6 +162,10 @@ The ``ec2`` key configures the EC2 instances created by auto-scaling groups (ASG
     The path of the linux device to attach the instance to
   ``VolumeSize``
     Size in gigabytes of the EBS volume
+  ``VolumeType (optional)``
+    The type of the volume to create. One of standard (default), gp2 or io1 (see `AWS API reference <http://docs.aws.amazon.com/AWSEC2/latest/APIReference/API_CreateVolume.html>`_)
+  ``Iops (Required for io1 type)``
+    The Iops value to assign to the io1 volume type.
 
   Example::
 
@@ -172,6 +176,7 @@ The ``ec2`` key configures the EC2 instances created by auto-scaling groups (ASG
           - DeviceName: /dev/sda1
             VolumeSize: 10
           - DeviceName: /dev/sdf
+            VolumeType: gp2
             VolumeSize: 100
 
 :``security_groups``:

bootstrap_cfn/config.py

@@ -865,9 +865,24 @@ def ec2(self):
         devices = []
         try:
             for i in data['block_devices']:
+                device_name = i['DeviceName']
+                volume_size = i.get('VolumeSize', 20)
+                volume_type = i.get('VolumeType', 'standard')
+                iops = i.get('Iops', False)
+                # Check we have a permitted volume type
+                if volume_type not in ['standard', 'gp2', 'io1']:
+                    raise errors.CfnConfigError("config: Volume type '%s' but must be one of standard', 'gp2' or 'io1"
+                                                % (volume_type))
+                # We need to specifiy iops if we have a volume type of io1
+                if volume_type == 'io1' and not iops:
+                    raise errors.CfnConfigError("config: Volume type io1 must have Iops defined")
+
                 devices.append(BlockDeviceMapping(
-                    DeviceName=i['DeviceName'],
-                    Ebs=EBSBlockDevice(VolumeSize=i['VolumeSize']),
+                    DeviceName=device_name,
+                    Ebs=EBSBlockDevice(
+                        VolumeType=volume_type,
+                        VolumeSize=volume_size,
+                        Iops=iops),
                 ))
         except KeyError:
             devices.append(BlockDeviceMapping(

tests/sample-project.yaml

@@ -15,6 +15,7 @@ dev:
       - DeviceName: /dev/sda1
         VolumeSize: 10
       - DeviceName: /dev/sdf
+        VolumeType: gp2
         VolumeSize: 10
     security_groups:
       AnotherSG:

tests/test.py

@@ -29,6 +29,7 @@ def setUp(self):
                                   'block_devices': [{'DeviceName': '/dev/sda1',
                                                      'VolumeSize': 10},
                                                     {'DeviceName': '/dev/sdf',
+                                                     'VolumeType': 'gp2',
                                                      'VolumeSize': 10}],
                                   'parameters': {'InstanceType': 't2.micro',
                                                  'KeyName': 'default'},

tests/tests.py

@@ -1295,11 +1295,11 @@ def test_ec2(self):
             BlockDeviceMappings=[
                 {
                     "DeviceName": "/dev/sda1",
-                    "Ebs": {"VolumeSize": 10}
+                    "Ebs": {"Iops": False, "VolumeSize": 10, "VolumeType": "standard"}
                 },
                 {
                     "DeviceName": "/dev/sdf",
-                    "Ebs": {"VolumeSize": 10}
+                    "Ebs": {"Iops": False, "VolumeSize": 10, "VolumeType": "gp2"}
                 }
             ],
             KeyName="default",
@@ -1345,11 +1345,11 @@ def test_launchconfig_userdata(self):
             BlockDeviceMappings=[
                 {
                     "DeviceName": "/dev/sda1",
-                    "Ebs": {"VolumeSize": 10}
+                    "Ebs": {"Iops": False, "VolumeSize": 10, "VolumeType": "standard"}
                 },
                 {
                     "DeviceName": "/dev/sdf",
-                    "Ebs": {"VolumeSize": 10}
+                    "Ebs": {"Iops": False, "VolumeSize": 10, "VolumeType": "gp2"}
                 }
             ],
             KeyName="default",