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// Copyright 2016 The Prometheus Authors
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package kubernetes
import (
"context"
"fmt"
"net"
"strconv"
"github.com/go-kit/kit/log"
"github.com/go-kit/kit/log/level"
"github.com/prometheus/common/model"
"github.com/prometheus/prometheus/discovery/targetgroup"
"github.com/prometheus/prometheus/util/strutil"
apiv1 "k8s.io/api/core/v1"
"k8s.io/client-go/tools/cache"
"k8s.io/client-go/util/workqueue"
)
const (
NodeLegacyHostIP = "LegacyHostIP"
)
// Node discovers Kubernetes nodes.
type Node struct {
logger log.Logger
informer cache.SharedInformer
store cache.Store
queue *workqueue.Type
}
// NewNode returns a new node discovery.
func NewNode(l log.Logger, inf cache.SharedInformer) *Node {
if l == nil {
l = log.NewNopLogger()
}
n := &Node{logger: l, informer: inf, store: inf.GetStore(), queue: workqueue.NewNamed("node")}
n.informer.AddEventHandler(cache.ResourceEventHandlerFuncs{
AddFunc: func(o interface{}) {
eventCount.WithLabelValues("node", "add").Inc()
n.enqueue(o)
},
DeleteFunc: func(o interface{}) {
eventCount.WithLabelValues("node", "delete").Inc()
n.enqueue(o)
},
UpdateFunc: func(_, o interface{}) {
eventCount.WithLabelValues("node", "update").Inc()
n.enqueue(o)
},
})
return n
}
func (n *Node) enqueue(obj interface{}) {
key, err := cache.DeletionHandlingMetaNamespaceKeyFunc(obj)
if err != nil {
return
}
n.queue.Add(key)
}
// Run implements the Discoverer interface.
func (n *Node) Run(ctx context.Context, ch chan<- []*targetgroup.Group) {
defer n.queue.ShutDown()
if !cache.WaitForCacheSync(ctx.Done(), n.informer.HasSynced) {
level.Error(n.logger).Log("msg", "node informer unable to sync cache")
return
}
go func() {
for n.process(ctx, ch) {
}
}()
// Block until the target provider is explicitly canceled.
<-ctx.Done()
}
func (n *Node) process(ctx context.Context, ch chan<- []*targetgroup.Group) bool {
keyObj, quit := n.queue.Get()
if quit {
return false
}
defer n.queue.Done(keyObj)
key := keyObj.(string)
_, name, err := cache.SplitMetaNamespaceKey(key)
if err != nil {
return true
}
o, exists, err := n.store.GetByKey(key)
if err != nil {
return true
}
if !exists {
send(ctx, n.logger, RoleNode, ch, &targetgroup.Group{Source: nodeSourceFromName(name)})
return true
}
node, err := convertToNode(o)
if err != nil {
level.Error(n.logger).Log("msg", "converting to Node object failed", "err", err)
return true
}
send(ctx, n.logger, RoleNode, ch, n.buildNode(node))
return true
}
func convertToNode(o interface{}) (*apiv1.Node, error) {
node, ok := o.(*apiv1.Node)
if ok {
return node, nil
}
return nil, fmt.Errorf("Received unexpected object: %v", o)
}
func nodeSource(n *apiv1.Node) string {
return nodeSourceFromName(n.Name)
}
func nodeSourceFromName(name string) string {
return "node/" + name
}
const (
nodeNameLabel = metaLabelPrefix + "node_name"
nodeLabelPrefix = metaLabelPrefix + "node_label_"
nodeAnnotationPrefix = metaLabelPrefix + "node_annotation_"
nodeAddressPrefix = metaLabelPrefix + "node_address_"
)
func nodeLabels(n *apiv1.Node) model.LabelSet {
ls := make(model.LabelSet, len(n.Labels)+len(n.Annotations)+1)
ls[nodeNameLabel] = lv(n.Name)
for k, v := range n.Labels {
ln := strutil.SanitizeLabelName(nodeLabelPrefix + k)
ls[model.LabelName(ln)] = lv(v)
}
for k, v := range n.Annotations {
ln := strutil.SanitizeLabelName(nodeAnnotationPrefix + k)
ls[model.LabelName(ln)] = lv(v)
}
return ls
}
func (n *Node) buildNode(node *apiv1.Node) *targetgroup.Group {
tg := &targetgroup.Group{
Source: nodeSource(node),
}
tg.Labels = nodeLabels(node)
addr, addrMap, err := nodeAddress(node)
if err != nil {
level.Warn(n.logger).Log("msg", "No node address found", "err", err)
return nil
}
addr = net.JoinHostPort(addr, strconv.FormatInt(int64(node.Status.DaemonEndpoints.KubeletEndpoint.Port), 10))
t := model.LabelSet{
model.AddressLabel: lv(addr),
model.InstanceLabel: lv(node.Name),
}
for ty, a := range addrMap {
ln := strutil.SanitizeLabelName(nodeAddressPrefix + string(ty))
t[model.LabelName(ln)] = lv(a[0])
}
tg.Targets = append(tg.Targets, t)
return tg
}
// nodeAddresses returns the provided node's address, based on the priority:
// 1. NodeInternalIP
// 2. NodeExternalIP
// 3. NodeLegacyHostIP
// 3. NodeHostName
//
// Derived from k8s.io/kubernetes/pkg/util/node/node.go
func nodeAddress(node *apiv1.Node) (string, map[apiv1.NodeAddressType][]string, error) {
m := map[apiv1.NodeAddressType][]string{}
for _, a := range node.Status.Addresses {
m[a.Type] = append(m[a.Type], a.Address)
}
if addresses, ok := m[apiv1.NodeInternalIP]; ok {
return addresses[0], m, nil
}
if addresses, ok := m[apiv1.NodeExternalIP]; ok {
return addresses[0], m, nil
}
if addresses, ok := m[apiv1.NodeAddressType(NodeLegacyHostIP)]; ok {
return addresses[0], m, nil
}
if addresses, ok := m[apiv1.NodeHostName]; ok {
return addresses[0], m, nil
}
return "", m, fmt.Errorf("host address unknown")
}