Implement inline CIDR block egress peer

This PR adds support for implementing inline CIDR peer blocks. Signed-off-by: Surya Seetharaman <[email protected]>
kubernetes-sigs · Feb 13, 2024 · f84e679 · f84e679
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diff --git a/apis/v1alpha1/shared_types.go b/apis/v1alpha1/shared_types.go
@@ -175,6 +175,23 @@ type AdminNetworkPolicyEgressPeer struct {
 	// <network-policy-api:experimental>
 	// +optional
 	Nodes *metav1.LabelSelector `json:"nodes,omitempty"`
+	// Networks defines a way to select peers via CIDR blocks (both v4 & v6).
+	// This is intended for representing entities that live outside the cluster,
+	// which can't be selected by pods, namespaces and nodes peers, but note
+	// that cluster-internal traffic will be checked against the rule as
+	// well. So if you Allow or Deny traffic to `"0.0.0.0/0"`, that will allow
+	// or deny all IPv4 pod-to-pod traffic as well. If you don't want that,
+	// add a rule that Passes all pod traffic before the Networks rule.
+	//
+	// Each item in Networks should be provided in the CIDR format and should be
+	// IPv4 or IPv6, for example "10.0.0.0/8" or "fd00::/8".
+	// Support: Extended
+	//
+	// <network-policy-api:experimental>
+	// +optional
+	// +kubebuilder:validation:MinItems=1
+	// +kubebuilder:validation:MaxItems=100
+	Networks []CIDR `json:"networks,omitempty"`
 }
 
 // NamespacedPeer defines a flexible way to select Namespaces in a cluster.
@@ -237,3 +254,11 @@ type NamespacedPodPeer struct {
 	//
 	PodSelector metav1.LabelSelector `json:"podSelector"`
 }
+
+// CIDR is an IP address range in CIDR notation (for example, "10.0.0.0/8" or "fd00::/8").
+// +kubebuilder:validation:Pattern=`(^(([0-9]|[1-9][0-9]|1[0-9]{2}|2[0-4][0-9]|25[0-5])\.){3}([0-9]|[1-9][0-9]|1[0-9]{2}|2[0-4][0-9]|25[0-5])(\/(3[0-2]|[1-2][0-9]|[0-9]))$)|(^s*((([0-9A-Fa-f]{1,4}:){7}([0-9A-Fa-f]{1,4}|:))|(([0-9A-Fa-f]{1,4}:){6}(:[0-9A-Fa-f]{1,4}|((25[0-5]|2[0-4]d|1dd|[1-9]?d)(.(25[0-5]|2[0-4]d|1dd|[1-9]?d)){3})|:))|(([0-9A-Fa-f]{1,4}:){5}(((:[0-9A-Fa-f]{1,4}){1,2})|:((25[0-5]|2[0-4]d|1dd|[1-9]?d)(.(25[0-5]|2[0-4]d|1dd|[1-9]?d)){3})|:))|(([0-9A-Fa-f]{1,4}:){4}(((:[0-9A-Fa-f]{1,4}){1,3})|((:[0-9A-Fa-f]{1,4})?:((25[0-5]|2[0-4]d|1dd|[1-9]?d)(.(25[0-5]|2[0-4]d|1dd|[1-9]?d)){3}))|:))|(([0-9A-Fa-f]{1,4}:){3}(((:[0-9A-Fa-f]{1,4}){1,4})|((:[0-9A-Fa-f]{1,4}){0,2}:((25[0-5]|2[0-4]d|1dd|[1-9]?d)(.(25[0-5]|2[0-4]d|1dd|[1-9]?d)){3}))|:))|(([0-9A-Fa-f]{1,4}:){2}(((:[0-9A-Fa-f]{1,4}){1,5})|((:[0-9A-Fa-f]{1,4}){0,3}:((25[0-5]|2[0-4]d|1dd|[1-9]?d)(.(25[0-5]|2[0-4]d|1dd|[1-9]?d)){3}))|:))|(([0-9A-Fa-f]{1,4}:){1}(((:[0-9A-Fa-f]{1,4}){1,6})|((:[0-9A-Fa-f]{1,4}){0,4}:((25[0-5]|2[0-4]d|1dd|[1-9]?d)(.(25[0-5]|2[0-4]d|1dd|[1-9]?d)){3}))|:))|(:(((:[0-9A-Fa-f]{1,4}){1,7})|((:[0-9A-Fa-f]{1,4}){0,5}:((25[0-5]|2[0-4]d|1dd|[1-9]?d)(.(25[0-5]|2[0-4]d|1dd|[1-9]?d)){3}))|:)))(%.+)?s*(\/(12[0-8]|1[0-1][0-9]|[1-9][0-9]|[0-9]))$)`
+// + ---
+// + The regex for the IPv4 and IPv6 CIDR range was taken from
+// + https://blog.markhatton.co.uk/2011/03/15/regular-expressions-for-ip-addresses-cidr-ranges-and-hostnames/
+// + The resulting regex is an OR of both regexes.
+type CIDR string
diff --git a/apis/v1alpha1/zz_generated.deepcopy.go b/apis/v1alpha1/zz_generated.deepcopy.go
diff --git a/config/crd/experimental/policy.networking.k8s.io_adminnetworkpolicies.yaml b/config/crd/experimental/policy.networking.k8s.io_adminnetworkpolicies.yaml
@@ -249,6 +249,27 @@ spec:
                                 maxItems: 100
                                 type: array
                             type: object
+                          networks:
+                            description: "Networks defines a way to select peers via
+                              CIDR blocks (both v4 & v6). This is intended for representing
+                              entities that live outside the cluster, which can't
+                              be selected by pods, namespaces and nodes peers, but
+                              note that cluster-internal traffic will be checked against
+                              the rule as well. So if you Allow or Deny traffic to
+                              `\"0.0.0.0/0\"`, that will allow or deny all IPv4 pod-to-pod
+                              traffic as well. If you don't want that, add a rule
+                              that Passes all pod traffic before the Networks rule.
+                              \n Each item in Networks should be provided in the CIDR
+                              format and should be IPv4 or IPv6, for example \"10.0.0.0/8\"
+                              or \"fd00::/8\". Support: Extended \n <network-policy-api:experimental>"
+                            items:
+                              description: CIDR is an IP address range in CIDR notation
+                                (for example, "10.0.0.0/8" or "fd00::/8").
+                              pattern: (^(([0-9]|[1-9][0-9]|1[0-9]{2}|2[0-4][0-9]|25[0-5])\.){3}([0-9]|[1-9][0-9]|1[0-9]{2}|2[0-4][0-9]|25[0-5])(\/(3[0-2]|[1-2][0-9]|[0-9]))$)|(^s*((([0-9A-Fa-f]{1,4}:){7}([0-9A-Fa-f]{1,4}|:))|(([0-9A-Fa-f]{1,4}:){6}(:[0-9A-Fa-f]{1,4}|((25[0-5]|2[0-4]d|1dd|[1-9]?d)(.(25[0-5]|2[0-4]d|1dd|[1-9]?d)){3})|:))|(([0-9A-Fa-f]{1,4}:){5}(((:[0-9A-Fa-f]{1,4}){1,2})|:((25[0-5]|2[0-4]d|1dd|[1-9]?d)(.(25[0-5]|2[0-4]d|1dd|[1-9]?d)){3})|:))|(([0-9A-Fa-f]{1,4}:){4}(((:[0-9A-Fa-f]{1,4}){1,3})|((:[0-9A-Fa-f]{1,4})?:((25[0-5]|2[0-4]d|1dd|[1-9]?d)(.(25[0-5]|2[0-4]d|1dd|[1-9]?d)){3}))|:))|(([0-9A-Fa-f]{1,4}:){3}(((:[0-9A-Fa-f]{1,4}){1,4})|((:[0-9A-Fa-f]{1,4}){0,2}:((25[0-5]|2[0-4]d|1dd|[1-9]?d)(.(25[0-5]|2[0-4]d|1dd|[1-9]?d)){3}))|:))|(([0-9A-Fa-f]{1,4}:){2}(((:[0-9A-Fa-f]{1,4}){1,5})|((:[0-9A-Fa-f]{1,4}){0,3}:((25[0-5]|2[0-4]d|1dd|[1-9]?d)(.(25[0-5]|2[0-4]d|1dd|[1-9]?d)){3}))|:))|(([0-9A-Fa-f]{1,4}:){1}(((:[0-9A-Fa-f]{1,4}){1,6})|((:[0-9A-Fa-f]{1,4}){0,4}:((25[0-5]|2[0-4]d|1dd|[1-9]?d)(.(25[0-5]|2[0-4]d|1dd|[1-9]?d)){3}))|:))|(:(((:[0-9A-Fa-f]{1,4}){1,7})|((:[0-9A-Fa-f]{1,4}){0,5}:((25[0-5]|2[0-4]d|1dd|[1-9]?d)(.(25[0-5]|2[0-4]d|1dd|[1-9]?d)){3}))|:)))(%.+)?s*(\/(12[0-8]|1[0-1][0-9]|[1-9][0-9]|[0-9]))$)
+                              type: string
+                            maxItems: 100
+                            minItems: 1
+                            type: array
                           nodes:
                             description: "Nodes defines a way to select a set of nodes
                               in the cluster. This field follows standard label selector

diff --git a/config/crd/experimental/policy.networking.k8s.io_baselineadminnetworkpolicies.yaml b/config/crd/experimental/policy.networking.k8s.io_baselineadminnetworkpolicies.yaml
@@ -241,6 +241,27 @@ spec:
                                 maxItems: 100
                                 type: array
                             type: object
+                          networks:
+                            description: "Networks defines a way to select peers via
+                              CIDR blocks (both v4 & v6). This is intended for representing
+                              entities that live outside the cluster, which can't
+                              be selected by pods, namespaces and nodes peers, but
+                              note that cluster-internal traffic will be checked against
+                              the rule as well. So if you Allow or Deny traffic to
+                              `\"0.0.0.0/0\"`, that will allow or deny all IPv4 pod-to-pod
+                              traffic as well. If you don't want that, add a rule
+                              that Passes all pod traffic before the Networks rule.
+                              \n Each item in Networks should be provided in the CIDR
+                              format and should be IPv4 or IPv6, for example \"10.0.0.0/8\"
+                              or \"fd00::/8\". Support: Extended \n <network-policy-api:experimental>"
+                            items:
+                              description: CIDR is an IP address range in CIDR notation
+                                (for example, "10.0.0.0/8" or "fd00::/8").
+                              pattern: (^(([0-9]|[1-9][0-9]|1[0-9]{2}|2[0-4][0-9]|25[0-5])\.){3}([0-9]|[1-9][0-9]|1[0-9]{2}|2[0-4][0-9]|25[0-5])(\/(3[0-2]|[1-2][0-9]|[0-9]))$)|(^s*((([0-9A-Fa-f]{1,4}:){7}([0-9A-Fa-f]{1,4}|:))|(([0-9A-Fa-f]{1,4}:){6}(:[0-9A-Fa-f]{1,4}|((25[0-5]|2[0-4]d|1dd|[1-9]?d)(.(25[0-5]|2[0-4]d|1dd|[1-9]?d)){3})|:))|(([0-9A-Fa-f]{1,4}:){5}(((:[0-9A-Fa-f]{1,4}){1,2})|:((25[0-5]|2[0-4]d|1dd|[1-9]?d)(.(25[0-5]|2[0-4]d|1dd|[1-9]?d)){3})|:))|(([0-9A-Fa-f]{1,4}:){4}(((:[0-9A-Fa-f]{1,4}){1,3})|((:[0-9A-Fa-f]{1,4})?:((25[0-5]|2[0-4]d|1dd|[1-9]?d)(.(25[0-5]|2[0-4]d|1dd|[1-9]?d)){3}))|:))|(([0-9A-Fa-f]{1,4}:){3}(((:[0-9A-Fa-f]{1,4}){1,4})|((:[0-9A-Fa-f]{1,4}){0,2}:((25[0-5]|2[0-4]d|1dd|[1-9]?d)(.(25[0-5]|2[0-4]d|1dd|[1-9]?d)){3}))|:))|(([0-9A-Fa-f]{1,4}:){2}(((:[0-9A-Fa-f]{1,4}){1,5})|((:[0-9A-Fa-f]{1,4}){0,3}:((25[0-5]|2[0-4]d|1dd|[1-9]?d)(.(25[0-5]|2[0-4]d|1dd|[1-9]?d)){3}))|:))|(([0-9A-Fa-f]{1,4}:){1}(((:[0-9A-Fa-f]{1,4}){1,6})|((:[0-9A-Fa-f]{1,4}){0,4}:((25[0-5]|2[0-4]d|1dd|[1-9]?d)(.(25[0-5]|2[0-4]d|1dd|[1-9]?d)){3}))|:))|(:(((:[0-9A-Fa-f]{1,4}){1,7})|((:[0-9A-Fa-f]{1,4}){0,5}:((25[0-5]|2[0-4]d|1dd|[1-9]?d)(.(25[0-5]|2[0-4]d|1dd|[1-9]?d)){3}))|:)))(%.+)?s*(\/(12[0-8]|1[0-1][0-9]|[1-9][0-9]|[0-9]))$)
+                              type: string
+                            maxItems: 100
+                            minItems: 1
+                            type: array
                           nodes:
                             description: "Nodes defines a way to select a set of nodes
                               in the cluster. This field follows standard label selector