[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
}