Extending HPA for K8S

Kubernetes clusters using ONAP Multicloud K8s Plugin Project for R4/R5 do not report hardware features to A&AI.
Consequently during the CNF/VNF life cycle CNFs/VNFs that require or recommend specific hardware during instantiation cannot dynamically reach the correct cluster and node that provides the needed hardware capabilities.

This Frankfurt Release epic (MULTICLOUD-729: Extend HPA to enable K8s instantiation using HPAClosed) adds the ability to discover, report and use hardware features during CNF/VNF life cycle to accelerate use cases using ONAP.

Overall Flow Diagram for HPA for K8s

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Discovery and Labeling of Node Features

The below figure shows a K8s cluster registering with the K8s plugin, wherein capabilities are transmitted

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Discovery of HPA features will be done using the node feature discovery [NFD] addon (https://github.com/kubernetes-sigs/node-feature-discovery) for kubernetes.  NFD will be deployed as a daemonSet, with pods on each node and will discover and label hardware features on each kubernetes node with features labels (https://github.com/kubernetes-sigs/node-feature-discovery#feature-labels).

For SR-IOV Add Network Controllers Class "0200" to NFD-Worker Config File on deploy to label network cards on nodes

For HPA Features not labeled by NFD, investigate creation of Feature Detector Hooks (User Specific Features)

Registering of K8s Clusters

The GREEN FLOW is Register HPA features to AAI.

Registration of K8s Cluster will happen at the ESR UI (see: https://onap.readthedocs.io/en/latest/guides/onap-user/cloud_site/openstack/index.html - use k8s for cloud-type). ESR will then send a POST request to 

^{http://{{MSB_IP}}:{{MSB_PORT}}/api/v1/{{cloud-owner}}/{{cloud-region-id}}/registry}

Multicloud K8s Plugin registrationHandler will receive said POST and register the new Kubernetes cluster with the K8s Plugin using the connectivity code/API.

The registrationHandler will then query the k8s cluster under registration using the Node App or Node Plugin code to get a list of nodes and the labels for each node.

• registrationHandler - onap/multicloud-k8s/src/k8splugin/api/registrationhandler.go

• Registers K8s cloud to K8s plugin using onap/multicloud-k8s/src/k8splugin/internal/connection/connection.go – check into if we need kubeconfig or ESR change

• Requires update of onap/multicloud-k8s/src/k8splugin/api/api.go

• Invokes AAI Client to K8s AAI Module to update AAI with Cloud/Tenant/Flavor information for the cluster

Node App or Node Plugin

• Node App - onap/multicloud-k8s/src/k8splugin/internal/app/node or onap/multicloud-k8s/src/k8splugin/internal/plugin/node.go

• Requests labels from nodes in K8s cluster

• Requires update of onap/multicloud-k8s/src/k8splugin/internal/app/client.go extend to node Resource (helm.KubernetesResource does not have resource type)

Reporting of Cluster Info to AA&I

Reporting of HPA features to AA&I is done by the registrationHandler. Data will be munged to cloud-region/tenant/flavors schema for that cluster and reported to AA&I. registrationHandler is planning on using AA&I module under development for Frankfurt to report to AA&I. In this case we will send a request to the AA&I module instructing it to update the cloud-region, create a tenant and create flavors that match the node feature labels in said cloud-region.

Convert node feature label to flavor properties

below table is example how to convert node feature label to flavor properties

We can get the latest mapping table in HPA Policies and Mappings + K8s

Update of CNF Artifacts to Include nodeSelector

CNF and VNF helm charts will be updated with nodeSelector requirements & recommendations in line with node labels created by NFD during feature discovery.
Example Node Features: 

Where needed add resource limits and request to ResourceBundle charts. I.E.:

^{resources: requests: memory: "64Mi" cpu: "250m" limits: memory: "128Mi" cpu: "500m"}

Charts to Update

https://github.com/onap/multicloud-k8s/tree/master/kud/demo/firewall

https://github.com/onap/multicloud-k8s/tree/master/kud/tests/vnfs/edgex/helm/edgex

For CPU Pinning etc - investigate CMK for kubernetes (see links at bottom of page) and specifying nodeSelector of "cmk.intel.com/cmk-node": "true"

Instantiation of K8s HPA

See Deploying vFw and EdgeXFoundry Services on Kubernets Cluster with ONAP for instantiation flow for K8s. See https://docs.onap.org/en/latest/submodules/integration.git/docs/docs_vfwHPA.html?highlight=hpa VFW deployment with HPA for HPA use case.

If we follow the deploying vFW for K8s on ONAP, the only difference in the process for HPA would be the addition of homing (see VFW deployment with HPA docs above) to the SO instantiation request. This enables a call to OOF that uses AA&I and Policy to select the correct cluster.  

Policy and OOF will use the same path to discover capabilities of K8s nodes as are done for OpenStack. We are using the same data model (OpenStack cloud-region/tenant/flavors) from AA&I. OOF will use AA&I information to home particular CNF workloads to cloud-regions which contain requested features. When K8s plugin instantiates said workloads Kubernetes will read nodeSelector preferences and place each workload on nodes which contain needed features to accelerate their function.

High Level Task Overview

MULTICLOUD-729: Extend HPA to enable K8s instantiation using HPAClosed

• Ensure NFD (Node feature discovery - K8S CNCF project) deploy to Multicloud + K8s Plugin is working and labeling Kubernetes nodes MULTICLOUD-741: Ensure Node Feature Discovery Usable for Single/Multiple Node Deploys using K8s plugin codeClosed

• Add registrationHandler to K8s Plugin and expand K8s Plugin API to work with ESR VIM registration of K8s Clusters MULTICLOUD-740: Create Register Module in K8s Plugin Enabling ONAP cloud registrationClosed
  
  

  • Use POST/DELETE/GET of http://{{MSB_IP}}:{{MSB_PORT}}/api/multicloud-k8s/v1/{{cloud-owner}}/{{cloud-region-id}}/registry 

  • Ensure registrationHandler can get K8s feature labels - (labels discovered and placed by NFD representing hardware features)

  • Ensure registrationHandler can populate A&AI cloud-region/tenant/compute flavors based on cluster under registration
    MULTICLOUD-739: Map K8s tenant model to OpenStack Tenant model in AAIClosed

  • Register K8s cluster internally with the K8s Plugin

• Add Node App in K8s Plugin to retrieve node labels from a cluster

• Identify and Address any gaps in policy and OOF to do match making of CNFs/VNFs using K8s Plugin

• Update CNF packages (Resource Bundles, CSAR) to include nodeSelector and resource requests and limits

• Update docs for HPA and K8s and Multicloud and ESR to reflect any change
  
  MULTICLOUD-742: Document use of HPA in K8s pluginClosed

Identify & Address Gaps in AAI/ESR Cloud Registration

AAI-2640: Enhance ESR to register/un-register Kubernetes based Cloud regionsClosed

Identify & Address Gaps to Policy and OOF for K8s HPA Homing

As of now there are not any known gaps in OOF/Policy that would inhibit this from working.

Background Links:

Deploying vFw and EdgeXFoundry Services on Kubernets Cluster with ONAP

vFW K8S examples mapping to AAI

Setting up Closed Loop for K8S vFW - initial pass

https://github.com/intel/CPU-Manager-for-Kubernetes

https://github.com/kubernetes-sigs/node-feature-discovery

https://github.com/kubernetes-sigs/node-feature-discovery#feature-detector-hooks-user-specific-features

https://kubernetes.io/docs/tasks/configure-pod-container/assign-cpu-resource/

https://kubernetes.io/docs/tasks/administer-cluster/topology-manager/

https://kubernetes.io/docs/tasks/configure-pod-container/assign-memory-resource/

https://kubernetes.io/docs/tasks/administer-cluster/extended-resource-node/