Using boto3 to update a cloudformation template
<p>I am trying to use boto3 to update an existing CloudFormation template, but my code fails on the 'Parameters' property! Here is what I have tried:</p>

<ol>
<li><p>Read params from a config file</p>

<pre><code>from ConfigParser import SafeConfigParser  
parser = SafeConfigParser()  
parser.optionxform=str  
parser.read( '/parms/SecGrpsParams.cfg')  
parms = dict(parser.items('params'))
</code></pre></li>
</ol>

<p>print parms" produces</p>

<blockquote>
  <p>{'Application': 'Click2Buy', 'AdminCidr': '10.0.0.0/8', 'AppMoniker': 'c2b', 'vId': 'vpc-3bec005f'}</p>
</blockquote>

<ol start="2">
<li><p>Call update_stack</p>

<pre><code>client = boto3.client('cloudformation')  
response = client.update_stack(  
    StackName = args.stackname,  
    TemplateURL = template,  
    Parameters = args.params,  
    Capabilities = ['CAPABILITY_IAM']  
 )
</code></pre></li>
<li><p>And the code produces this error:<br>
botocore.exceptions.ParamValidationError: Parameter validation failed:
Invalid type for parameter Parameters,<br>
value: {'Application': 'Click2Buy', 'AdminCidr': '10.0.0.0/8', 'AppMoniker': 'c2b', 'vId': 'vpc-3bec005f'},<br>
type: type: , valid types: , </p></li>
</ol>

<p>I have tried to <code>args.params.items()</code>, <code>[args.params]</code>, and <code>[args.params.items()]</code> but can't figure out what is needed.</p>