Since pkgtools has been modified to support different tosca parser backend to validate the tosca template syntax, we need to investigate the following different candidates, and choose which one we'd like to use to validate against the new VNFD model.

choosing standards:

• python based or provide restful APIs so pkgtools can be easily integrated with
• support custom changes/extensions in tosca, so we can use that for HPA specific purpose

Potential candidates, needs to be investitated

• aria tosca parser: https://github.com/apache/incubator-ariatosca/, which is current the default pkgtool parser backend
• nfv parser: https://github.com/opnfv/parser/, based on openstack tosca-parser
• parser as a service: there is on-going discussion in onap now, https://wiki.onap.org/pages/viewpage.action?pageId=24641685