now processing relabeling rules for prometheus

obtaining all required monitoring endpoints now seems to work.
This commit is contained in:
Erik Brakkee 2025-01-29 21:08:42 +01:00
parent 2bea96cc57
commit 2373f428bb
8 changed files with 568 additions and 16 deletions

View File

@ -6,40 +6,409 @@ import (
v1 "k8s.io/api/core/v1"
metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
"k8s.io/apimachinery/pkg/labels"
"k8s.io/apimachinery/pkg/runtime/schema"
"k8s.io/apimachinery/pkg/util/json"
"k8s.io/client-go/dynamic"
"k8s.io/client-go/kubernetes"
"k8s.io/klog/v2"
"log"
"os"
"slices"
"strconv"
"strings"
)
type ServiceMonitor struct {
metav1.TypeMeta `json:",inline"`
metav1.ObjectMeta `json:"metadata,omitempty"`
Spec ServiceMonitorSpec `json:"spec"`
}
type ServiceMonitorSpec struct {
NamespaceSelector NamespaceSelector `json:"namespaceSelector"`
Selector metav1.LabelSelector `json:"selector"`
Endpoints []Endpoint `json:"endpoints"`
}
type Endpoint struct {
Path string `json:"path,omitempty"`
Port string `json:"port"`
TargetPort string `json:"targetPort"`
Scheme string `json:"scheme,omitempty"`
Relabelings []RelabelConfig `json:"relabelings,omitempty"`
}
type PodMonitor struct {
metav1.TypeMeta `json:",inline"`
metav1.ObjectMeta `json:"metadata,omitempty"`
Spec PodMonitorSpec `json:"spec"`
}
type PodMonitorSpec struct {
NamespaceSelector NamespaceSelector `json:"namespaceSelector"`
Selector metav1.LabelSelector `json:"selector"`
PodMetricsEndpoints []Endpoint `json:"podMetricsEndpoints"`
}
type NamespaceSelector struct {
Any bool `json:"any,omitempty"`
MatchNames []string `json:"matchNames,omitempty"`
}
type RelabelConfig struct {
Action string `json:"action,omitempty"`
SourceLabels []string `json:"sourceLabels,omitempty"`
Separator string `json:"separator,omitempty"`
TargetLabel string `json:"targetLabel,omitempty"`
Regex string `json:"regex,omitempty"`
Modulus uint64 `json:"modulus,omitempty"`
Replacement string `json:"replacement,omitempty"`
}
type Cluster struct {
namespaces map[string]v1.Namespace
clientset *kubernetes.Clientset
dynClient *dynamic.DynamicClient
// map of namespace to list of all pods
pods map[string][]v1.Pod
pods map[string][]v1.Pod
services map[string][]v1.Service
// map of namespace/podname ->: ScrapingEndpoints
endpoints map[string]MonitoringEndpoints
}
func NewCluster(clientset *kubernetes.Clientset) (*Cluster, error) {
type MonitoringEndpoint struct {
Port string
Path string
}
type MonitoringEndpoints []MonitoringEndpoint
func (s MonitoringEndpoint) CompareTo(e MonitoringEndpoint) int {
if res := strings.Compare(s.Port, e.Port); res != 0 {
return res
}
return strings.Compare(s.Path, e.Path)
}
func (s *MonitoringEndpoints) Merge(endpoints MonitoringEndpoints) {
*s = append(*s, endpoints...)
slices.SortFunc(*s, func(a, b MonitoringEndpoint) int {
return a.CompareTo(b)
})
*s = slices.CompactFunc(*s, func(a, b MonitoringEndpoint) bool {
return a.CompareTo(b) == 0
})
}
func NewCluster(clientset *kubernetes.Clientset, dynClient *dynamic.DynamicClient) (*Cluster, error) {
cluster := &Cluster{
clientset: clientset,
clientset: clientset,
dynClient: dynClient,
namespaces: make(map[string]v1.Namespace),
pods: make(map[string][]v1.Pod),
services: make(map[string][]v1.Service),
endpoints: make(map[string]MonitoringEndpoints),
}
nslist, err := cluster.clientset.CoreV1().Namespaces().List(context.Background(), metav1.ListOptions{})
if err != nil {
return nil, err
}
fmt.Fprintf(os.Stderr, "Getting pods, services\n")
for _, ns := range nslist.Items {
cluster.namespaces[ns.Name] = ns
podList, err := cluster.clientset.CoreV1().Pods(ns.Name).List(context.Background(), metav1.ListOptions{})
if err != nil {
return nil, err
}
cluster.pods[ns.Name] = podList.Items
}
podList, err := cluster.clientset.CoreV1().Pods("").List(context.Background(), metav1.ListOptions{})
if err != nil {
return nil, err
}
for _, pod := range podList.Items {
cluster.pods[pod.Namespace] = append(cluster.pods[pod.Namespace], pod)
}
svcList, err := cluster.clientset.CoreV1().Services("").List(context.Background(), metav1.ListOptions{})
if err != nil {
return nil, err
}
for _, svc := range svcList.Items {
cluster.services[svc.Namespace] = append(cluster.services[svc.Namespace], svc)
}
err = cluster.processServiceMonitors()
if err != nil {
return nil, err
}
err = cluster.procewssPodMonitors()
if err != nil {
return nil, err
}
podkeys := MapKeys(cluster.endpoints)
slices.Sort(podkeys)
for _, pod := range podkeys {
monitors := cluster.endpoints[pod]
slices.SortFunc(monitors,
func(m1, m2 MonitoringEndpoint) int {
return m1.CompareTo(m2)
})
monitors = slices.CompactFunc(monitors,
func(m1, m2 MonitoringEndpoint) bool {
return m1.CompareTo(m2) == 0
})
cluster.endpoints[pod] = monitors
fmt.Fprintf(os.Stderr, "monitoring endpoint: %s: %v\n", pod, monitors)
}
return cluster, nil
}
func (c *Cluster) processPodMonitor(podMonitor PodMonitor) error {
selector, err := metav1.LabelSelectorAsSelector(&podMonitor.Spec.Selector)
if err != nil {
return err
}
namespaces := c.getNamespacesForMonitor(podMonitor.Spec.NamespaceSelector, podMonitor.Namespace)
for _, endpoint := range podMonitor.Spec.PodMetricsEndpoints {
for _, relabeling := range endpoint.Relabelings {
if relabeling.Action != "keep" {
continue
}
fmt.Fprintf(os.Stderr, "WARNING: podmonitor %s/%s contains relabeling which are currently not processed\n",
podMonitor.Namespace, podMonitor.Name)
}
}
for _, namespace := range namespaces {
pods := slices.DeleteFunc(slices.Clone(c.pods[namespace]), func(pod v1.Pod) bool {
return !selector.Matches(labels.Set(pod.Labels))
})
for _, pod := range pods {
podkey := pod.Namespace + "/" + pod.Name
klog.V(3).Infof(" match %s/%s\n", pod.Namespace, pod.Name)
for _, container := range pod.Spec.Containers {
for _, endpoint := range podMonitor.Spec.PodMetricsEndpoints {
ep, err := c.getEndpointSpec(endpoint, &pod, &container, container.Ports)
if err != nil {
// TODO generate warning?
// this container did not match
continue
}
c.endpoints[podkey] = append(c.endpoints[podkey], ep...)
}
}
if len(c.endpoints[podkey]) > 0 {
klog.V(3).Infof(" POD %s/%s :%v\n", pod.Namespace, pod.Name,
c.endpoints[podkey])
}
}
}
return nil
}
func (c *Cluster) getNamespacesForMonitor(namespaceSelector NamespaceSelector, defaultNamespace string) []string {
namespaces := MapKeys(c.namespaces)
if !namespaceSelector.Any {
namespaces = namespaceSelector.MatchNames
if len(namespaces) == 0 {
namespaces = []string{defaultNamespace}
}
}
return namespaces
}
func (c *Cluster) processServiceMonitor(serviceMonitor ServiceMonitor) error {
selector, err := metav1.LabelSelectorAsSelector(&serviceMonitor.Spec.Selector)
if err != nil {
return err
}
namespaces := c.getNamespacesForMonitor(serviceMonitor.Spec.NamespaceSelector,
serviceMonitor.Namespace)
for _, endpoint := range serviceMonitor.Spec.Endpoints {
for _, relabeling := range endpoint.Relabelings {
if relabeling.Action != "keep" {
continue
}
fmt.Fprintf(os.Stderr, "WARNING: servicemonitor %s/%s contains relabeling which are currently not processed\n",
serviceMonitor.Namespace, serviceMonitor.Name)
}
}
for _, namespace := range namespaces {
svcs := slices.DeleteFunc(slices.Clone(c.services[namespace]), func(svc v1.Service) bool {
return !selector.Matches(labels.Set(svc.Labels))
})
for _, svc := range svcs {
klog.V(3).Infof(" match %s/%s\n", svc.Namespace, svc.Name)
if svc.Spec.Selector == nil {
fmt.Fprintf(os.Stderr, " service does not have a selector, skippingit, probably configured using endpoints\n")
continue
}
// Now we need to obtain the pod port.
// 1. Port specified
// service targetPort is used (equal to port if not specified)
// a. lookup pods matched by the service using the service selector
// b. path is /metics or the metric defined in the service selector
// c. port, path is defined and poss are known.
// 2. Target port specified
// a, b, c see above.
svcSelector := labels.SelectorFromSet(labels.Set(svc.Spec.Selector))
// find pods
pods := slices.DeleteFunc(slices.Clone(c.pods[svc.Namespace]), func(pod v1.Pod) bool {
return !svcSelector.Matches(labels.Set(pod.Labels))
})
for _, endpoint := range serviceMonitor.Spec.Endpoints {
for _, pod := range pods {
podkey := pod.Namespace + "/" + pod.Name
for _, container := range pod.Spec.Containers {
ep, err := c.getEndpointSpec(endpoint, &pod, &container, container.Ports)
if err != nil {
// TODO: generate warning?
// this wervice did not match
}
c.endpoints[podkey] = append(c.endpoints[podkey], ep...)
}
if len(c.endpoints[podkey]) > 0 {
klog.V(3).Infof(" POD %s/%s :%v\n", pod.Namespace, pod.Name,
c.endpoints[podkey])
}
}
}
}
}
return nil
}
type GeneralizedPort struct {
Name string
TargetPort string
Protocol string
}
func MapServicePorts(ports []v1.ServicePort) []GeneralizedPort {
return Map(ports, func(p v1.ServicePort) GeneralizedPort {
return GeneralizedPort{
Name: p.Name,
TargetPort: p.TargetPort.String(),
Protocol: string(p.Protocol),
}
})
}
func MapConteinerPorts(ports []v1.ContainerPort) []GeneralizedPort {
return Map(ports, func(p v1.ContainerPort) GeneralizedPort {
return GeneralizedPort{
Name: p.Name,
TargetPort: strconv.Itoa(int(p.ContainerPort)),
Protocol: string(p.Protocol),
}
})
}
func (c *Cluster) getEndpointSpec(endpoint Endpoint, pod *v1.Pod, container *v1.Container, ports []v1.ContainerPort) ([]MonitoringEndpoint, error) {
klog.V(4).Infof(" analyzing %s/%s container %s/%s %v\n",
endpoint.Port, endpoint.TargetPort, pod.Name, container.Name, ports)
res := []MonitoringEndpoint{}
portLoop:
for _, port := range ports {
targetPort := ""
switch {
case endpoint.Port != "":
//fmt.Fprintf(os.Stderr, "Checking %v %s\n", port.Port, endpoint.Port)
if port.Name != endpoint.Port {
continue
}
case endpoint.TargetPort != "":
if strconv.Itoa(int(port.ContainerPort)) != endpoint.TargetPort {
continue
}
}
if targetPort == "" {
if port.Name != "" {
targetPort = port.Name
} else {
targetPort = strconv.Itoa(int(port.ContainerPort))
}
}
// check relabeling configs
for _, relabeling := range endpoint.Relabelings {
match, err := MatchRelabeling(relabeling, pod, container, &port)
if err != nil {
return nil, err
}
if !match {
continue portLoop
}
}
// port matches all criteria
path := "/metrics"
if endpoint.Path != "" {
path = endpoint.Path
}
ep := MonitoringEndpoint{
Port: targetPort,
Path: path,
}
res = append(res, ep)
}
return res, nil
}
func (c *Cluster) processServiceMonitors() error {
fmt.Fprintf(os.Stderr, "Getting service monitors\n")
serviceMonitorGVR := schema.GroupVersionResource{
Group: "monitoring.coreos.com",
Version: "v1",
Resource: "servicemonitors",
}
list, err := c.dynClient.Resource(serviceMonitorGVR).
Namespace("").
List(context.Background(), metav1.ListOptions{})
if err != nil {
return err
}
for _, item := range list.Items {
var sm ServiceMonitor
bytes, _ := json.Marshal(item.Object)
if err := json.Unmarshal(bytes, &sm); err != nil {
return fmt.Errorf("Error unmarshalling %s: %w", bytes, err)
}
klog.V(2).Infof("Found servicemonitor: %s/%s\n", sm.ObjectMeta.Namespace, sm.ObjectMeta.Name)
if err := c.processServiceMonitor(sm); err != nil {
return err
}
}
return nil
}
func (c *Cluster) procewssPodMonitors() error {
fmt.Fprintf(os.Stderr, "Getting pod monitors\n")
podMonitorGVR := schema.GroupVersionResource{
Group: "monitoring.coreos.com",
Version: "v1",
Resource: "podmonitors",
}
list, err := c.dynClient.Resource(podMonitorGVR).
Namespace("").
List(context.Background(), metav1.ListOptions{})
if err != nil {
return err
}
for _, item := range list.Items {
var pm PodMonitor
bytes, _ := json.Marshal(item.Object)
if err := json.Unmarshal(bytes, &pm); err != nil {
return fmt.Errorf("Error unmarshalling %s: %w", bytes, err)
}
klog.V(2).Infof("Found podmonitor: %s/%s\n", pm.ObjectMeta.Namespace, pm.ObjectMeta.Name)
if err := c.processPodMonitor(pm); err != nil {
return err
}
}
return nil
}
func (c *Cluster) Pods(application *Application) []v1.Pod {
selector, err := metav1.LabelSelectorAsSelector(application.Selector())
if err != nil {

View File

@ -35,13 +35,13 @@ func IterToSlice[K any](i iter.Seq[K]) []K {
}
func validate(files []string, options *Options) error {
clientset, _ := GetKubernetesConnection()
clientset, dynClient, _ := GetKubernetesConnection()
config, err := readConfig(files)
if err != nil {
return err
}
cluster, err := NewCluster(clientset)
cluster, err := NewCluster(clientset, dynClient)
if err != nil {
return err
}

View File

@ -1,12 +1,13 @@
package main
import (
"k8s.io/client-go/dynamic"
"k8s.io/client-go/kubernetes"
"k8s.io/client-go/tools/clientcmd"
"log"
)
func GetKubernetesConnection() (*kubernetes.Clientset, string) {
func GetKubernetesConnection() (*kubernetes.Clientset, *dynamic.DynamicClient, string) {
loadingRules := clientcmd.NewDefaultClientConfigLoadingRules()
configOverrides := &clientcmd.ConfigOverrides{}
kubeConfig := clientcmd.NewNonInteractiveDeferredLoadingClientConfig(loadingRules, configOverrides)
@ -20,12 +21,16 @@ func GetKubernetesConnection() (*kubernetes.Clientset, string) {
clientset, err := kubernetes.NewForConfig(config)
if err != nil {
log.Panicln(err.Error())
panic(err)
}
dynamicClient, err := dynamic.NewForConfig(config)
if err != nil {
panic(err)
}
namespace, _, err := kubeConfig.Namespace()
if err != nil {
log.Panicf("Could not get namespace")
}
return clientset, namespace
return clientset, dynamicClient, namespace
}

View File

@ -1,8 +1,10 @@
package main
import (
goflags "flag"
"fmt"
"github.com/spf13/cobra"
"k8s.io/klog/v2"
"os"
)
@ -59,11 +61,12 @@ func generateLinkerdPolicies(files []string, options *Options) error {
if err != nil {
return err
}
clientset, _ := GetKubernetesConnection()
cluster, err := NewCluster(clientset)
clientset, dynClient, _ := GetKubernetesConnection()
cluster, err := NewCluster(clientset, dynClient)
if err != nil {
return err
}
fmt.Fprintf(os.Stderr, "Enhancing configuration based on running cluster\n")
config.Infer(cluster)
policyTemplates, err := NewPolicyTemplates()
@ -81,6 +84,8 @@ func generateLinkerdPolicies(files []string, options *Options) error {
}
func main() {
klogFlags := goflags.NewFlagSet("", goflags.PanicOnError)
klog.InitFlags(klogFlags)
options := Options{
cni: "cilium",

150
cmd/policygen/prometheus.go Normal file
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@ -0,0 +1,150 @@
package main
import (
"fmt"
v1 "k8s.io/api/core/v1"
"k8s.io/klog/v2"
"regexp"
"slices"
"strconv"
"strings"
)
var standardPodLabels = map[string]func(pod *v1.Pod) string{
"__meta_kubernetes_pod_name": func(pod *v1.Pod) string { return pod.Name },
"__meta_kubernetes_pod_ip": func(pod *v1.Pod) string { return pod.Status.PodIP },
"__meta_kubernetes_pod_node_name": func(pod *v1.Pod) string { return pod.Spec.NodeName },
"__meta_kubernetes_pod_uid": func(pod *v1.Pod) string { return string(pod.UID) },
"__meta_kubernetes_pod_phase": func(pod *v1.Pod) string { return string(pod.Status.Phase) },
"__meta_kubernetes_pod_ready": func(pod *v1.Pod) string { return getPodReadyCondition(pod) },
"__meta_kubernetes_pod_host_ip": func(pod *v1.Pod) string { return pod.Status.HostIP },
"__meta_kubernetes_namespace": func(pod *v1.Pod) string { return pod.Namespace },
"__meta_kubernetes_pod_container_init": func(pod *v1.Pod) string { return "false" },
"__meta_kubernetes_pod_service_account": func(pod *v1.Pod) string { return pod.Spec.ServiceAccountName },
"__meta_kubernetes_pod_controller_kind": func(pod *v1.Pod) string { return getControllerKind(pod) },
"__meta_kubernetes_pod_controller_name": func(pod *v1.Pod) string { return getControllerName(pod) },
}
var containerLabels = map[string]func(pod *v1.Pod, container *v1.Container) string{
"__meta_kubernetes_pod_container_name": func(pod *v1.Pod, container *v1.Container) string {
return container.Name
},
"__meta_kubernetes_pod_container_id": func(pod *v1.Pod, container *v1.Container) string {
return getContainerID(pod, container)
},
}
func metadataPodLabels(pod *v1.Pod) map[string]string {
labels := make(map[string]string)
for name, value := range pod.Labels {
key := "__meta_kubernetes_pod_label_" + strings.ReplaceAll(name, ".", "_")
key = strings.ReplaceAll(key, "/", "_")
key = strings.ReplaceAll(key, "-", "_")
labels[key] = value
}
for name, value := range pod.Annotations {
key := "__meta_kubernetes_pod_annotation_" + strings.ReplaceAll(name, ".", "_")
key = strings.ReplaceAll(key, "/", "_")
key = strings.ReplaceAll(key, "-", "_")
labels[key] = value
}
klog.V(6).Infof("METADATA LABELS %v\n", labels)
return labels
}
func getContainerPortSourceLabels(port *v1.ContainerPort) map[string]string {
labels := make(map[string]string)
labels["__meta_kubernetes_pod_container_port_name"] = port.Name
labels["__meta_kubernetes_pod_container_port_number"] = strconv.FormatInt(int64(port.ContainerPort), 10)
labels["__meta_kubernetes_pod_container_port_protocol"] = string(port.Protocol)
return labels
}
type RelabelingMatcher func(pod *v1.Pod) ([]v1.ContainerPort, error)
func MatchRelabeling(config RelabelConfig, pod *v1.Pod, container *v1.Container,
port *v1.ContainerPort) (bool, error) {
if config.Action != "keep" {
return true, nil
}
labelValues := make([]string, len(config.SourceLabels))
for isource, sourceLabel := range config.SourceLabels {
if podLabelFunc, ok := standardPodLabels[sourceLabel]; ok {
labelValues[isource] = podLabelFunc(pod)
continue
}
metadataLabels := metadataPodLabels(pod)
if metadataLabelValue, ok := metadataLabels[sourceLabel]; ok {
labelValues[isource] = metadataLabelValue
continue
}
if containerLabelFunc, ok := containerLabels[sourceLabel]; ok {
labelValues[isource] = containerLabelFunc(pod, container)
continue
}
containerPortSourceLabels := getContainerPortSourceLabels(port)
if containerPortValue, ok := containerPortSourceLabels[sourceLabel]; ok {
labelValues[isource] = containerPortValue
continue
}
}
// concatenate the label values
labelstring := strings.Join(labelValues, ";")
matched, err := regexp.MatchString(config.Regex, labelstring)
if err != nil {
return false, err
}
klog.V(5).Infof(" relabeling '%s' ~ '%s': %v\n", labelstring, config.Regex, matched)
return matched, err
}
func combinations(s [][]string, i int, sequence []string) {
if i == len(s) {
fmt.Printf("COMBINATION %v\n", sequence)
return
}
for _, v := range s[i] {
sequence[i] = v
combinations(s, i+1, sequence)
}
}
// Helper functions
func getPodReadyCondition(pod *v1.Pod) string {
for _, condition := range pod.Status.Conditions {
if condition.Type == v1.PodReady {
if condition.Status == v1.ConditionTrue {
return "true"
}
return "false"
}
}
return "unknown"
}
func getContainerID(pod *v1.Pod, container *v1.Container) string {
containerIndex := slices.IndexFunc(pod.Spec.Containers, func(c v1.Container) bool {
return c.Name == container.Name
})
id := pod.Status.ContainerStatuses[containerIndex].ContainerID
// Strip the docker:// prefix if present
return strings.TrimPrefix(id, "docker://")
}
func getControllerKind(pod *v1.Pod) string {
for _, owner := range pod.OwnerReferences {
if owner.Controller != nil && *owner.Controller {
return owner.Kind
}
}
return ""
}
func getControllerName(pod *v1.Pod) string {
for _, owner := range pod.OwnerReferences {
if owner.Controller != nil && *owner.Controller {
return owner.Name
}
}
return ""
}

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@ -0,0 +1,2 @@
# a rule that allows ingress from monitoring

View File

@ -0,0 +1,20 @@
---
# a Server matching all pods
# 1. must scan podmonitors and service monitoros
# must scan for all applicable podmonitor and servicemonitor resources
# Based on namespaceSelector: any (bool), matchNames ([]string)
# spec.selector determines the pods.
#
# 2. determine pods targeted
# 2. for each targeted pod, determine the port number
# 3. for each targeted pod determine the application it belongs to (so we know the labels to use)
# 4. create a rule for the given port to the given application to allow access by monitoring.
#
# Build mapping of application -> pod
# pod -> podmonitors -> port(s)
# pod -> endpoint
#
# linkerd scraping port
# linkerd-admin port on linkerd-proxy containers in any namespace, as long as they have the label linkerd.io/control-plane-ns=linkerd.
# a MeshTlsAuthentication matching all pods

3
go.mod
View File

@ -12,6 +12,8 @@ require (
k8s.io/api v0.32.0
k8s.io/apimachinery v0.32.0
k8s.io/client-go v0.32.0
k8s.io/klog/v2 v2.130.1
)
require (
@ -59,7 +61,6 @@ require (
gopkg.in/evanphx/json-patch.v4 v4.12.0 // indirect
gopkg.in/inf.v0 v0.9.1 // indirect
gopkg.in/yaml.v3 v3.0.1 // indirect
k8s.io/klog/v2 v2.130.1 // indirect
k8s.io/kube-openapi v0.0.0-20241105132330-32ad38e42d3f // indirect
k8s.io/utils v0.0.0-20241104100929-3ea5e8cea738 // indirect
sigs.k8s.io/json v0.0.0-20241010143419-9aa6b5e7a4b3 // indirect