Wait for volume state

[e0d]

raidformer doesn't seem to wait for EBS volumes to become available before attempting to attach them. If there are not in the right state the following error occurs. I see this error nearly every time I run raidformer, even with small volumes. I can create a PR unless I'm missing something obvious.

Traceback (most recent call last):
  File "./raidformer.py", line 168, in <module>
    ec2conn.attach_volume(vol.id, instance_data['instance-id'], device)
  File "/usr/lib/python2.7/dist-packages/boto/ec2/connection.py", line 1369, in attach_volume
    return self.get_status('AttachVolume', params, verb='POST')
  File "/usr/lib/python2.7/dist-packages/boto/connection.py", line 935, in get_status
    raise self.ResponseError(response.status, response.reason, body)
boto.exception.EC2ResponseError: EC2ResponseError: 400 Bad Request
<?xml version="1.0" encoding="UTF-8"?>
<Response><Errors><Error><Code>IncorrectState</Code><Message>vol-c92fa384 is not 'available'.</Message></Error></Errors><RequestID>97f9ecf4-1b41-4c58-8254-63fc725057c8</RequestID></Response>

[jsmartin]

Hmm, interesting.. I'm ok with a pull request.. I thought I was waiting for the devices to be ready with this:

for device in attached_devices:
found = False

    while found is False:

        print "Waiting for %s to become available." % device
        if os.path.exists(device):
            print "%s has been found." % device
            break
        else:
            time.sleep(10)

But perhaps something has changed.

[e0d]

That waits for the device to show up upon attachment, the above error occurs when you call attach too soon.