Log the warning instead of raising an exception if input are not passed for tosca template raising

[bharaththiruveedula]

When I tried to parser the below template I got an error.

TEMPLATE:
tosca_definitions_version: tosca_simple_yaml_1_0

description: Template for deploying a single server with predefined properties.

topology_template:
  inputs:
    num_cpu:
        type: integer
  node_templates:
    my_server:
      type: tosca.nodes.Compute
      capabilities:
        # Host container properties
        host:
         properties:
           num_cpus: {get_input: num_cpu}
           disk_size: 10 GB
           mem_size: 512 MB
        # Guest Operating System properties
        os:
          properties:
            # host Operating System image properties
            architecture: x86_64
            type: Linux
            distribution: RHEL
            version: 6.5

ERROR:
The input "tosca_helloworld.yaml" failed validation with the following error(s):

 MissingRequiredParameterError: Template is missing required parameter for input "num_cpu".
  File /usr/local/bin/tosca-parser, line 10, in <module>
   sys.exit(main())
  File /usr/local/lib/python2.7/dist-packages/toscaparser/shell.py, line 104, in main
   ParserShell().main(args)
  File /usr/local/lib/python2.7/dist-packages/toscaparser/shell.py, line 59, in main
   self.parse(path)
  File /usr/local/lib/python2.7/dist-packages/toscaparser/shell.py, line 68, in parse
   tosca = ToscaTemplate(path, None, a_file)
  File /usr/local/lib/python2.7/dist-packages/toscaparser/tosca_template.py, line 101, in __init__
   self.topology_template = self._topology_template()
  File /usr/local/lib/python2.7/dist-packages/toscaparser/tosca_template.py, line 119, in _topology_template
   None)
  File /usr/local/lib/python2.7/dist-packages/toscaparser/topology_template.py, line 55, in __init__
   self.inputs = self._inputs()
  File /usr/local/lib/python2.7/dist-packages/toscaparser/topology_template.py, line 83, in _inputs
   input_name=input.name))

But this is not required output for some use cases. Instead of raising an exception we need to log that error

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/416698

[Sahdev Zala (spzala)]

There are cases where user may not want to provide any default e.g. password param or simply user want to provide value at the runtime so let's just log a warning message instead of failing.

[Sahdev Zala (spzala)]

Also in certain cases user may want to provide inputs via a separate configuration file at the runtime so logging only warning is more appropriate. If user miss providing such an input runtime failure should be considered as user error.

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/416698
Committed: https://git.openstack.org/cgit/openstack/tosca-parser/commit/?id=ed70f10d7a9a8c439655c19334b1e40b6116a756
Submitter: Jenkins
Branch: master

commit ed70f10d7a9a8c439655c19334b1e40b6116a756
Author: Bharath Thiruveedula <email address hidden>
Date: Wed Jan 4 23:45:45 2017 +0530

    Log the required inputs, instead of raising exceptions

    Change-Id: If154aeebf277b3374aaff9c6b5d1d9522ea6c13c
    Closes-Bug: #1653992