Files
weave/npc/namespace.go
Raj Chaudhuri c1d3107418 Changed module name, edited default manifests in prog/weave-kube
* Module name changed to `github.com/rajch/weave`
* Added environment variable `CHECKPOINT_DISABLE=1` to default manifests, to bypass weaveworks telemetry
2024-03-01 18:05:19 +05:30

617 lines
19 KiB
Go

package npc
import (
"errors"
"fmt"
coreapi "k8s.io/api/core/v1"
extnapi "k8s.io/api/extensions/v1beta1"
networkingv1 "k8s.io/api/networking/v1"
metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
"k8s.io/apimachinery/pkg/util/uuid"
"github.com/rajch/weave/common"
"github.com/rajch/weave/common/chains"
"github.com/rajch/weave/net/ipset"
"github.com/rajch/weave/npc/iptables"
)
var errInvalidNetworkPolicyObjType = errors.New("invalid NetworkPolicy object type")
type ns struct {
ipt iptables.Interface // interface to iptables
ips ipset.Interface // interface to ipset
name string // k8s Namespace name
nodeName string // my node name
namespaceUID ipset.UID // k8s Namespace UID
namespaceLabels map[string]string // k8s Namespace labels
pods map[ipset.UID]*coreapi.Pod // k8s Pod objects by UID
policies map[ipset.UID]interface{} // k8s NetworkPolicy objects by UID
uid ipset.UID // surrogate UID to own allPods selector
allPods *selectorSpec // hash:ip ipset of all pod IPs in this namespace
// stores IP addrs of pods which are not selected by any target podSelector of
// any netpol; used as a target in the WEAVE-NPC-{INGRESS,EGRESS}-DEFAULT
// iptables chains.
ingressDefaultAllowIPSet ipset.Name
egressDefaultAllowIPSet ipset.Name
nsSelectors *selectorSet // reference to global selectorSet that is shared across the `ns`. Used to represent all pods in the matching namespaces
podSelectors *selectorSet // used to represent the matching pods in namespace respresented by this `ns`
namespacedPodsSelectors *selectorSet // reference to global selectorSet that is shared across the `ns`. Used to represent matching pods in matching namespace
ipBlocks *ipBlockSet
rules *ruleSet
}
func newNS(name, nodeName string, ipt iptables.Interface, ips ipset.Interface, nsSelectors *selectorSet, namespacedPodsSelectors *selectorSet, namespaceObj *coreapi.Namespace) (*ns, error) {
allPods, err := newSelectorSpec(&metav1.LabelSelector{}, nil, nil, name, ipset.HashIP)
if err != nil {
return nil, err
}
ns := &ns{
ipt: ipt,
ips: ips,
name: name,
namespaceUID: nsuid(namespaceObj),
namespaceLabels: namespaceObj.ObjectMeta.Labels,
nodeName: nodeName,
pods: make(map[ipset.UID]*coreapi.Pod),
policies: make(map[ipset.UID]interface{}),
uid: ipset.UID(uuid.NewUUID()),
allPods: allPods,
nsSelectors: nsSelectors,
namespacedPodsSelectors: namespacedPodsSelectors,
ipBlocks: newIPBlockSet(ips),
rules: newRuleSet(ipt),
}
ns.podSelectors = newSelectorSet(ips, ns.onNewPodSelector, ns.onNewTargetPodSelector, ns.onDestroyTargetPodSelector)
ingressDefaultAllowIPSet := ipset.Name(IpsetNamePrefix + shortName("ingress-default-allow:"+name))
if err := ips.Create(ingressDefaultAllowIPSet, ipset.HashIP); err != nil {
return nil, err
}
ns.ingressDefaultAllowIPSet = ingressDefaultAllowIPSet
egressDefaultAllowIPSet := ipset.Name(IpsetNamePrefix + shortName("egress-default-allow:"+name))
if err := ips.Create(egressDefaultAllowIPSet, ipset.HashIP); err != nil {
return nil, err
}
ns.egressDefaultAllowIPSet = egressDefaultAllowIPSet
if err := ns.podSelectors.provision(ns.uid, nil, map[string]*selectorSpec{ns.allPods.key: ns.allPods}); err != nil {
return nil, err
}
return ns, nil
}
func (ns *ns) empty() bool {
return len(ns.pods) == 0 && len(ns.policies) == 0 && ns.namespaceUID == ""
}
func (ns *ns) destroy() error {
return ns.podSelectors.deprovision(ns.uid, map[string]*selectorSpec{ns.allPods.key: ns.allPods}, nil)
}
func (ns *ns) onNewPodSelector(selector *selector) error {
for _, pod := range ns.pods {
if hasIP(pod) {
if selector.matchesPodSelector(pod.ObjectMeta.Labels) {
if err := selector.addEntry(uid(pod), pod.Status.PodIP, podComment(pod)); err != nil {
return err
}
}
}
}
return nil
}
func (ns *ns) onNewTargetPodSelector(selector *selector, policyType policyType) error {
for _, pod := range ns.pods {
if hasIP(pod) {
// Remove the pod from default-allow if dst podselector matches the pod
ipset := ns.defaultAllowIPSetName(policyType)
if selector.matchesPodSelector(pod.ObjectMeta.Labels) {
if err := ns.ips.DelEntry(uid(pod), ipset, pod.Status.PodIP); err != nil {
return err
}
}
}
}
return nil
}
func (ns *ns) onDestroyTargetPodSelector(selector *selector, policyType policyType) error {
for _, pod := range ns.pods {
if hasIP(pod) {
if selector.matchesPodSelector(pod.ObjectMeta.Labels) {
if err := ns.addToDefaultAllowIfNoMatching(pod, policyType); err != nil {
return err
}
}
}
}
return nil
}
// Add pod IP addr to default-allow ipset if there are no matching target selectors
func (ns *ns) addToDefaultAllowIfNoMatching(pod *coreapi.Pod, policyType policyType) error {
found := false
// TODO(mp) optimize (avoid iterating over selectors) by ref counting IP addrs.
for _, s := range ns.podSelectors.entries {
if ns.podSelectors.targetSelectorExist(s, policyType) && s.matchesPodSelector(pod.ObjectMeta.Labels) {
found = true
break
}
}
if !found {
ipset := ns.defaultAllowIPSetName(policyType)
if err := ns.ips.AddEntry(uid(pod), ipset, pod.Status.PodIP, podComment(pod)); err != nil {
return err
}
}
return nil
}
func (ns *ns) addPod(obj *coreapi.Pod) error {
ns.pods[uid(obj)] = obj
if !hasIP(obj) {
return nil
}
foundIngress, foundEgress, err := ns.podSelectors.addToMatchingPodSelector(uid(obj), obj.ObjectMeta.Labels, obj.Status.PodIP, podComment(obj))
if err != nil {
return err
}
// If there are no matching target selectors, add the pod to default-allow
if !foundIngress {
if err := ns.ips.AddEntry(uid(obj), ns.ingressDefaultAllowIPSet, obj.Status.PodIP, podComment(obj)); err != nil {
return err
}
}
if !foundEgress {
if err := ns.ips.AddEntry(uid(obj), ns.egressDefaultAllowIPSet, obj.Status.PodIP, podComment(obj)); err != nil {
return err
}
}
err = ns.namespacedPodsSelectors.addToMatchingNamespacedPodSelector(uid(obj), obj.ObjectMeta.Labels, ns.namespaceLabels, obj.Status.PodIP, podComment(obj))
if err != nil {
return err
}
return nil
}
func (ns *ns) updatePod(oldObj, newObj *coreapi.Pod) error {
delete(ns.pods, uid(oldObj))
ns.pods[uid(newObj)] = newObj
if !hasIP(oldObj) && !hasIP(newObj) {
return nil
}
if hasIP(oldObj) && !hasIP(newObj) {
if err := ns.ips.DelEntry(uid(oldObj), ns.ingressDefaultAllowIPSet, oldObj.Status.PodIP); err != nil {
return err
}
if err := ns.ips.DelEntry(uid(oldObj), ns.egressDefaultAllowIPSet, oldObj.Status.PodIP); err != nil {
return err
}
if err := ns.namespacedPodsSelectors.delFromMatchingNamespacedPodSelector(uid(oldObj), oldObj.ObjectMeta.Labels, ns.namespaceLabels, oldObj.Status.PodIP); err != nil {
return err
}
return ns.podSelectors.delFromMatchingPodSelector(uid(oldObj), oldObj.ObjectMeta.Labels, oldObj.Status.PodIP)
}
if !hasIP(oldObj) && hasIP(newObj) {
foundIngress, foundEgress, err := ns.podSelectors.addToMatchingPodSelector(uid(newObj), newObj.ObjectMeta.Labels, newObj.Status.PodIP, podComment(newObj))
if err != nil {
return err
}
if !foundIngress {
if err := ns.ips.AddEntry(uid(newObj), ns.ingressDefaultAllowIPSet, newObj.Status.PodIP, podComment(newObj)); err != nil {
return err
}
}
if !foundEgress {
if err := ns.ips.AddEntry(uid(newObj), ns.egressDefaultAllowIPSet, newObj.Status.PodIP, podComment(newObj)); err != nil {
return err
}
}
err = ns.namespacedPodsSelectors.addToMatchingNamespacedPodSelector(uid(newObj), newObj.ObjectMeta.Labels, ns.namespaceLabels, newObj.Status.PodIP, podComment(newObj))
if err != nil {
return err
}
return nil
}
if oldObj.Status.PodIP != newObj.Status.PodIP {
if err := ns.updateDefaultAllowIPSetEntry(oldObj, newObj, ns.ingressDefaultAllowIPSet); err != nil {
return err
}
if err := ns.updateDefaultAllowIPSetEntry(oldObj, newObj, ns.egressDefaultAllowIPSet); err != nil {
return err
}
}
if !equals(oldObj.ObjectMeta.Labels, newObj.ObjectMeta.Labels) ||
oldObj.Status.PodIP != newObj.Status.PodIP {
for _, ps := range ns.podSelectors.entries {
oldMatch := ps.matchesPodSelector(oldObj.ObjectMeta.Labels)
newMatch := ps.matchesPodSelector(newObj.ObjectMeta.Labels)
if oldMatch == newMatch && oldObj.Status.PodIP == newObj.Status.PodIP {
continue
}
if oldMatch {
if err := ps.delEntry(uid(oldObj), oldObj.Status.PodIP); err != nil {
return err
}
}
if newMatch {
if err := ps.addEntry(uid(newObj), newObj.Status.PodIP, podComment(newObj)); err != nil {
return err
}
}
if err := ns.addOrRemoveToDefaultAllowIPSet(ps, oldObj, newObj, oldMatch, newMatch, policyTypeIngress); err != nil {
return err
}
if err := ns.addOrRemoveToDefaultAllowIPSet(ps, oldObj, newObj, oldMatch, newMatch, policyTypeEgress); err != nil {
return err
}
}
for _, ps := range ns.namespacedPodsSelectors.entries {
oldMatch := ps.matchesNamespacedPodSelector(oldObj.ObjectMeta.Labels, ns.namespaceLabels)
newMatch := ps.matchesNamespacedPodSelector(newObj.ObjectMeta.Labels, ns.namespaceLabels)
if oldMatch == newMatch && oldObj.Status.PodIP == newObj.Status.PodIP {
continue
}
if oldMatch {
if err := ps.delEntry(uid(oldObj), oldObj.Status.PodIP); err != nil {
return err
}
}
if newMatch {
if err := ps.addEntry(uid(newObj), newObj.Status.PodIP, podComment(newObj)); err != nil {
return err
}
}
}
}
return nil
}
func (ns *ns) addOrRemoveToDefaultAllowIPSet(ps *selector, oldObj, newObj *coreapi.Pod, oldMatch, newMatch bool, policyType policyType) error {
ipset := ns.defaultAllowIPSetName(policyType)
if ns.podSelectors.targetSelectorExist(ps, policyType) {
switch {
case !oldMatch && newMatch:
if err := ns.ips.DelEntry(uid(oldObj), ipset, oldObj.Status.PodIP); err != nil {
return err
}
case oldMatch && !newMatch:
if err := ns.addToDefaultAllowIfNoMatching(newObj, policyType); err != nil {
return err
}
}
}
return nil
}
func (ns *ns) deletePod(obj *coreapi.Pod) error {
delete(ns.pods, uid(obj))
if !hasIP(obj) {
return nil
}
if err := ns.ips.DelEntry(uid(obj), ns.ingressDefaultAllowIPSet, obj.Status.PodIP); err != nil {
return err
}
if err := ns.ips.DelEntry(uid(obj), ns.egressDefaultAllowIPSet, obj.Status.PodIP); err != nil {
return err
}
if err := ns.podSelectors.delFromMatchingPodSelector(uid(obj), obj.ObjectMeta.Labels, obj.Status.PodIP); err != nil {
return err
}
if err := ns.namespacedPodsSelectors.delFromMatchingNamespacedPodSelector(uid(obj), obj.ObjectMeta.Labels, ns.namespaceLabels, obj.Status.PodIP); err != nil {
return err
}
return nil
}
func (ns *ns) addNetworkPolicy(obj interface{}) error {
// Analyse policy, determine which rules and ipsets are required
uid, rules, nsSelectors, podSelectors, namespacedPodsSelectors, ipBlocks, err := ns.analyse(obj)
if err != nil {
return err
}
// Provision required resources in dependency order
if err := ns.nsSelectors.provision(uid, nil, nsSelectors); err != nil {
return err
}
if err := ns.podSelectors.provision(uid, nil, podSelectors); err != nil {
return err
}
if err := ns.namespacedPodsSelectors.provision(uid, nil, namespacedPodsSelectors); err != nil {
return err
}
if err := ns.ipBlocks.provision(uid, nil, ipBlocks); err != nil {
return err
}
return ns.rules.provision(uid, nil, rules)
}
func (ns *ns) updateNetworkPolicy(oldObj, newObj interface{}) error {
// Analyse the old and the new policy so we can determine differences
oldUID, oldRules, oldNsSelectors, oldPodSelectors, oldNamespacedPodsSelectors, oldIPBlocks, err := ns.analyse(oldObj)
if err != nil {
return err
}
newUID, newRules, newNsSelectors, newPodSelectors, newNamespacedPodsSelectors, newIPBlocks, err := ns.analyse(newObj)
if err != nil {
return err
}
delete(ns.policies, oldUID)
ns.policies[newUID] = newObj
// Deprovision unused and provision newly required resources in dependency order
if err := ns.rules.deprovision(oldUID, oldRules, newRules); err != nil {
return err
}
if err := ns.nsSelectors.deprovision(oldUID, oldNsSelectors, newNsSelectors); err != nil {
return err
}
if err := ns.podSelectors.deprovision(oldUID, oldPodSelectors, newPodSelectors); err != nil {
return err
}
if err := ns.namespacedPodsSelectors.deprovision(oldUID, oldNamespacedPodsSelectors, newNamespacedPodsSelectors); err != nil {
return err
}
if err := ns.ipBlocks.deprovision(oldUID, oldIPBlocks, newIPBlocks); err != nil {
return err
}
if err := ns.nsSelectors.provision(oldUID, oldNsSelectors, newNsSelectors); err != nil {
return err
}
if err := ns.podSelectors.provision(oldUID, oldPodSelectors, newPodSelectors); err != nil {
return err
}
if err := ns.namespacedPodsSelectors.provision(oldUID, oldNamespacedPodsSelectors, newNamespacedPodsSelectors); err != nil {
return err
}
if err := ns.ipBlocks.provision(oldUID, oldIPBlocks, newIPBlocks); err != nil {
return err
}
return ns.rules.provision(oldUID, oldRules, newRules)
}
func (ns *ns) deleteNetworkPolicy(obj interface{}) error {
// Analyse network policy to free resources
uid, rules, nsSelectors, podSelectors, namespacedPodsSelectors, ipBlocks, err := ns.analyse(obj)
if err != nil {
return err
}
delete(ns.policies, uid)
// Deprovision unused resources in dependency order
if err := ns.rules.deprovision(uid, rules, nil); err != nil {
return err
}
if err := ns.nsSelectors.deprovision(uid, nsSelectors, nil); err != nil {
return err
}
if err := ns.podSelectors.deprovision(uid, podSelectors, nil); err != nil {
return err
}
if err := ns.namespacedPodsSelectors.deprovision(uid, namespacedPodsSelectors, nil); err != nil {
return err
}
if err := ns.ipBlocks.deprovision(uid, ipBlocks, nil); err != nil {
return err
}
return nil
}
func (ns *ns) updateDefaultAllowIPSetEntry(oldObj, newObj *coreapi.Pod, ipsetName ipset.Name) error {
// Instead of iterating over all selectors we check whether old pod IP
// has been inserted into default-allow ipset to decide whether the IP
// in the ipset has to be updated.
if ns.ips.EntryExists(uid(oldObj), ipsetName, oldObj.Status.PodIP) {
if err := ns.ips.DelEntry(uid(oldObj), ipsetName, oldObj.Status.PodIP); err != nil {
return err
}
if err := ns.ips.AddEntry(uid(newObj), ipsetName, newObj.Status.PodIP, podComment(newObj)); err != nil {
return err
}
}
return nil
}
func bypassRules(namespace string, ingress, egress ipset.Name) map[string][][]string {
return map[string][][]string{
chains.DefaultChain: {
{"-m", "set", "--match-set", string(ingress), "dst", "-j", "ACCEPT",
"-m", "comment", "--comment", "DefaultAllow ingress isolation for namespace: " + namespace},
},
chains.EgressDefaultChain: {
{"-m", "set", "--match-set", string(egress), "src", "-j", chains.EgressMarkChain,
"-m", "comment", "--comment", "DefaultAllow egress isolation for namespace: " + namespace},
{"-m", "set", "--match-set", string(egress), "src", "-j", "RETURN",
"-m", "comment", "--comment", "DefaultAllow egress isolation for namespace: " + namespace},
},
}
}
func (ns *ns) ensureBypassRules() error {
for chain, rules := range bypassRules(ns.name, ns.ingressDefaultAllowIPSet, ns.egressDefaultAllowIPSet) {
for _, rule := range rules {
common.Log.Debugf("adding rule for DefaultAllow in namespace: %s, chain: %s, %s", ns.name, chain, rule)
if err := ns.ipt.Append(TableFilter, chain, rule...); err != nil {
return err
}
}
}
return nil
}
func (ns *ns) deleteBypassRules() error {
for chain, rules := range bypassRules(ns.name, ns.ingressDefaultAllowIPSet, ns.egressDefaultAllowIPSet) {
for _, rule := range rules {
common.Log.Debugf("removing rule for DefaultAllow in namespace: %s, chain: %s, %s", ns.name, chain, rule)
if err := ns.ipt.Delete(TableFilter, chain, rule...); err != nil {
return err
}
}
}
return nil
}
func (ns *ns) addNamespace(obj *coreapi.Namespace) error {
ns.namespaceUID = ipset.UID(obj.ObjectMeta.UID)
ns.namespaceLabels = obj.ObjectMeta.Labels
// Insert a rule to bypass policies
if err := ns.ensureBypassRules(); err != nil {
return err
}
// Add namespace ipset to matching namespace selectors
err := ns.nsSelectors.addToMatchingNamespaceSelector(nsuid(obj), obj.ObjectMeta.Labels, string(ns.allPods.ipsetName), namespaceComment(ns))
return err
}
func (ns *ns) updateNamespace(oldObj, newObj *coreapi.Namespace) error {
// Re-evaluate namespace selector membership if labels have changed
if !equals(oldObj.ObjectMeta.Labels, newObj.ObjectMeta.Labels) {
ns.namespaceLabels = newObj.ObjectMeta.Labels
for _, selector := range ns.nsSelectors.entries {
oldMatch := selector.matchesNamespaceSelector(oldObj.ObjectMeta.Labels)
newMatch := selector.matchesNamespaceSelector(newObj.ObjectMeta.Labels)
if oldMatch == newMatch {
continue
}
if oldMatch {
if err := selector.delEntry(ns.namespaceUID, string(ns.allPods.ipsetName)); err != nil {
return err
}
}
if newMatch {
if err := selector.addEntry(ns.namespaceUID, string(ns.allPods.ipsetName), namespaceComment(ns)); err != nil {
return err
}
}
}
}
return nil
}
func (ns *ns) deleteNamespace(obj *coreapi.Namespace) error {
ns.namespaceUID = ""
// Remove bypass rule
if err := ns.deleteBypassRules(); err != nil {
return err
}
// Remove namespace ipset from any matching namespace selectors
err := ns.nsSelectors.delFromMatchingNamespaceSelector(nsuid(obj), obj.ObjectMeta.Labels, string(ns.allPods.ipsetName))
if err != nil {
return err
}
if err := ns.ips.Destroy(ns.ingressDefaultAllowIPSet); err != nil {
return err
}
if err := ns.ips.Destroy(ns.egressDefaultAllowIPSet); err != nil {
return err
}
return nil
}
func hasIP(pod *coreapi.Pod) bool {
// Ensure pod isn't dead, has an IP address and isn't sharing the host network namespace
return pod.Status.Phase != "Succeeded" && pod.Status.Phase != "Failed" &&
len(pod.Status.PodIP) > 0 && !pod.Spec.HostNetwork
}
func equals(a, b map[string]string) bool {
if len(a) != len(b) {
return false
}
for ak, av := range a {
if b[ak] != av {
return false
}
}
return true
}
func namespaceComment(namespace *ns) string {
return "namespace: " + namespace.name
}
func podComment(pod *coreapi.Pod) string {
return fmt.Sprintf("namespace: %s, pod: %s", pod.ObjectMeta.Namespace, pod.ObjectMeta.Name)
}
func (ns *ns) defaultAllowIPSetName(pt policyType) ipset.Name {
ipset := ns.ingressDefaultAllowIPSet
if pt == policyTypeEgress {
ipset = ns.egressDefaultAllowIPSet
}
return ipset
}
func (ns *ns) analyse(obj interface{}) (
uid ipset.UID,
rules map[string]*ruleSpec,
nsSelectors, podSelectors, namespacedPodsSelectors map[string]*selectorSpec,
ipBlocks map[string]*ipBlockSpec,
err error) {
switch p := obj.(type) {
case *extnapi.NetworkPolicy:
uid = ipset.UID(p.ObjectMeta.UID)
case *networkingv1.NetworkPolicy:
uid = ipset.UID(p.ObjectMeta.UID)
default:
err = errInvalidNetworkPolicyObjType
return
}
ns.policies[uid] = obj
// Analyse policy, determine which rules and ipsets are required
rules, nsSelectors, podSelectors, namespacedPodsSelectors, ipBlocks, err = ns.analysePolicy(obj.(*networkingv1.NetworkPolicy))
if err != nil {
return
}
return
}