[Policy Assistant] Modify Data Structure for (B)ANP

[huntergregory]

Requirement for #150.

Cyclonus uses an interim data structure (matcher.Policy) for the NetworkPolicy. We can modify this to support a generic Policy representing a ANP, BANP, or NetworkPolicy.

New features include:

• SameLabels in Peer
• Namespace Selector in Target (Subject)
• Node Selector in Target/Peer
• Priority + Action

Code to Modify

Will need to make new implementations of PeerMatcher like those seen in TargetsTableLines().

type Policy struct {
        // NOTE: need policyKind here
	Ingress map[string]*Target
	Egress  map[string]*Target
}

func (p *Policy) IsIngressOrEgressAllowed(traffic *Traffic, isIngress bool) *DirectionResult {
       // NOTE: need new logic here
       // Targets can overlap now since ANP uses namespace selector
}

type Traffic struct {
	Source      *TrafficPeer
	Destination *TrafficPeer

	ResolvedPort     int
	ResolvedPortName string
	Protocol         v1.Protocol
}

type Target struct {
       // NOTE: need:
       // 1. Namespace selector
       // 2. Node Selector
	Namespace   string
	PodSelector metav1.LabelSelector
	Peers       []PeerMatcher
	SourceRules []*networkingv1.NetworkPolicy // need ANP/BNP option
	primaryKey  string
}

type PeerMatcher interface {
	Allows(peer *TrafficPeer, portInt int, portName string, protocol v1.Protocol) bool
       // NOTE: need argument for target’s pod/node labels (to help with SameLabels)
       // NOTE: return value must be (policyKind, priority, action)
}

type TrafficPeer struct {
	Internal *InternalPeer
	IP       string
}

type InternalPeer struct {
	PodLabels map[string]string
	NamespaceLabels map[string]string
	Namespace       string
       // NOTE: need:
       // 1. Node
       // 2. Node labels
}