Study of how to implement TCS Control Loops using a TOSCA appraoch

Cloudify support is being removed from DCAE in the Jakarta release and this decision impacts on the Policy Framework

• CLAMP flow for Control Loop Deployment using Cloudify is broken, we will not be able to do a Control Loop deployment in DCAE using Cloudify blueprints
• The best approach would be to use the TOSCA based approach and retire the support for the Cloudy approach
• We will keep the Cloudify code for this release, and move forward with the TOSCA/Participant approach
• For the TCA use case, we will get it working with the TOSCA/Participant approach
• There will not be much client impacts
• The CLAMP front end will remain, as it supports the TOSCA/Participant approach and also supports Policy creation and Service Template
• Sébastien Determe  has already checked the CLAMP front end code in policy/gui so it is OK to remove the CLAMP front end code from the policy/clamp repo
• The DCAE design for blueprint processing in DCAE-MOD now works towards a chart museum, so this part of the flow will change
• Some of the current work flow may be replaced with manual steps and/or with the TOSCA/Participant Commissioning/Instantiation flows
• We will use the PMSH use case as a starting point
• There is development happening in SDC in Jakarta to support TOSCA based control loops, see this EPIC:  POLICY-2952 - R10: TOSCA Control Loop Design Time In Progress
• Possible improvements in Jakarta and beyond
  • Possibility to list available microservices and other control loop elements at design time
  • Possibility to list running/viable microservices and other control loop elements at run time
• Currently CLAMP queries CDS for information but this is a "nice to have" rather than a "must have" feature
• We will have to change pairwise testing and tests run by OOM to use the changed Control Loop implementation
• Actions Arising:
  • Gervais-Martial Ngueko  will prepare a wiki page in  the Jakarta collaboration area no the next steps
  • Liam Fallon  will coordinate removal of the CLAMP front end code in the policy/clamp repo

See the Policy Framework meeting minutes from the 15th of December, 2021
https://wiki.onap.org/display/Meetings/2021-12-15+Policy+Weekly+Meeting

This story covers the work to study how TCS Control Loops can be implemented using the TOSCA approach.