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| 1 | +package routeutils |
| 2 | + |
| 3 | +import ( |
| 4 | + "context" |
| 5 | + v1 "k8s.io/api/core/v1" |
| 6 | + metav1 "k8s.io/apimachinery/pkg/apis/meta/v1" |
| 7 | + "k8s.io/apimachinery/pkg/util/sets" |
| 8 | + "sigs.k8s.io/controller-runtime/pkg/client" |
| 9 | + gwv1 "sigs.k8s.io/gateway-api/apis/v1" |
| 10 | +) |
| 11 | + |
| 12 | +type ListenerToRouteMapper interface { |
| 13 | + Map(context context.Context, client client.Client, gw *gwv1.Gateway, routes []RouteDescriptor) (map[int][]RouteDescriptor, error) |
| 14 | +} |
| 15 | + |
| 16 | +var _ ListenerToRouteMapper = &listenerToRouteMapper{} |
| 17 | + |
| 18 | +type listenerToRouteMapper struct { |
| 19 | +} |
| 20 | + |
| 21 | +func (ltr *listenerToRouteMapper) Map(ctx context.Context, k8sclient client.Client, gw *gwv1.Gateway, routes []RouteDescriptor) (map[int][]RouteDescriptor, error) { |
| 22 | + result := make(map[int][]RouteDescriptor) |
| 23 | + |
| 24 | + // Approach is to greedily add as many relevant routes to each listener. |
| 25 | + for _, listener := range gw.Spec.Listeners { |
| 26 | + for _, route := range routes { |
| 27 | + allowedAttachment, err := ltr.listenerAllowsAttachment(ctx, k8sclient, gw, listener, route) |
| 28 | + if err != nil { |
| 29 | + return nil, err |
| 30 | + } |
| 31 | + |
| 32 | + if allowedAttachment { |
| 33 | + result[int(listener.Port)] = append(result[int(listener.Port)], route) |
| 34 | + } |
| 35 | + } |
| 36 | + } |
| 37 | + return result, nil |
| 38 | +} |
| 39 | + |
| 40 | +func (ltr *listenerToRouteMapper) listenerAllowsAttachment(ctx context.Context, k8sclient client.Client, gw *gwv1.Gateway, listener gwv1.Listener, route RouteDescriptor) (bool, error) { |
| 41 | + namespaceOK, err := ltr.namespaceCheck(ctx, k8sclient, gw, listener, route) |
| 42 | + if err != nil { |
| 43 | + return false, err |
| 44 | + } |
| 45 | + |
| 46 | + if !namespaceOK { |
| 47 | + return false, nil |
| 48 | + } |
| 49 | + |
| 50 | + if !ltr.kindCheck(listener, route) { |
| 51 | + return false, nil |
| 52 | + } |
| 53 | + return true, nil |
| 54 | +} |
| 55 | + |
| 56 | +func (ltr *listenerToRouteMapper) namespaceCheck(ctx context.Context, k8sclient client.Client, gw *gwv1.Gateway, listener gwv1.Listener, route RouteDescriptor) (bool, error) { |
| 57 | + if listener.AllowedRoutes == nil { |
| 58 | + return gw.Namespace == route.GetRouteNamespace(), nil |
| 59 | + } |
| 60 | + |
| 61 | + var allowedNamespaces gwv1.FromNamespaces |
| 62 | + |
| 63 | + if listener.AllowedRoutes.Namespaces == nil || listener.AllowedRoutes.Namespaces.From == nil { |
| 64 | + allowedNamespaces = gwv1.NamespacesFromSame |
| 65 | + } else { |
| 66 | + allowedNamespaces = *listener.AllowedRoutes.Namespaces.From |
| 67 | + } |
| 68 | + |
| 69 | + switch allowedNamespaces { |
| 70 | + case gwv1.NamespacesFromSame: |
| 71 | + if gw.Namespace != route.GetRouteNamespace() { |
| 72 | + return false, nil |
| 73 | + } |
| 74 | + break |
| 75 | + case gwv1.NamespacesFromSelector: |
| 76 | + if listener.AllowedRoutes.Namespaces.Selector == nil { |
| 77 | + return false, nil |
| 78 | + } |
| 79 | + // This should be executed off the client-go cache, hence we do not need to perform local caching. |
| 80 | + namespaces, err := ltr.getNamespacesFromSelector(ctx, k8sclient, listener.AllowedRoutes.Namespaces.Selector) |
| 81 | + if err != nil { |
| 82 | + return false, err |
| 83 | + } |
| 84 | + |
| 85 | + if !namespaces.Has(route.GetRouteNamespace()) { |
| 86 | + return false, nil |
| 87 | + } |
| 88 | + break |
| 89 | + case gwv1.NamespacesFromAll: |
| 90 | + // Nothing to check |
| 91 | + break |
| 92 | + default: |
| 93 | + // Unclear what to do in this case, let's try to be best effort and just ignore this value. |
| 94 | + return false, nil |
| 95 | + } |
| 96 | + |
| 97 | + return false, nil |
| 98 | +} |
| 99 | + |
| 100 | +func (ltr *listenerToRouteMapper) kindCheck(listener gwv1.Listener, route RouteDescriptor) bool { |
| 101 | + |
| 102 | + var allowedRoutes sets.Set[string] |
| 103 | + |
| 104 | + // Allowed Routes being null defaults to no checking required. |
| 105 | + if listener.AllowedRoutes.Kinds == nil { |
| 106 | + allowedRoutes = sets.New[string](defaultProtocolToRouteKindMap[listener.Protocol]) |
| 107 | + } else { |
| 108 | + // TODO - Not sure how to handle versioning (correctly) here. |
| 109 | + // So going to ignore the group checks for now :x |
| 110 | + allowedRoutes = sets.New[string]() |
| 111 | + for _, v := range listener.AllowedRoutes.Kinds { |
| 112 | + allowedRoutes.Insert(string(v.Kind)) |
| 113 | + } |
| 114 | + } |
| 115 | + return allowedRoutes.Has(route.GetRouteKind()) |
| 116 | +} |
| 117 | + |
| 118 | +func (ltr *listenerToRouteMapper) getNamespacesFromSelector(context context.Context, k8sclient client.Client, selector *metav1.LabelSelector) (sets.Set[string], error) { |
| 119 | + namespaceList := v1.NamespaceList{} |
| 120 | + |
| 121 | + convertedSelector, err := metav1.LabelSelectorAsSelector(selector) |
| 122 | + if err != nil { |
| 123 | + return nil, err |
| 124 | + } |
| 125 | + listOpts := client.ListOptions{LabelSelector: convertedSelector} |
| 126 | + |
| 127 | + err = k8sclient.List(context, &namespaceList, &listOpts) |
| 128 | + if err != nil { |
| 129 | + return nil, err |
| 130 | + } |
| 131 | + |
| 132 | + namespaces := sets.New[string]() |
| 133 | + |
| 134 | + for _, ns := range namespaceList.Items { |
| 135 | + namespaces.Insert(ns.Name) |
| 136 | + } |
| 137 | + |
| 138 | + return namespaces, nil |
| 139 | +} |
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