prometheus/discovery/kubernetes/pod.go
Tariq Ibrahim 8fdfa8abea refine error handling in prometheus (#5388)
i) Uses the more idiomatic Wrap and Wrapf methods for creating nested errors.
ii) Fixes some incorrect usages of fmt.Errorf where the error messages don't have any formatting directives.
iii) Does away with the use of fmt package for errors in favour of pkg/errors

Signed-off-by: tariqibrahim <tariq181290@gmail.com>
2019-03-26 00:01:12 +01:00

258 lines
7.3 KiB
Go

// 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"
"net"
"strconv"
"strings"
"github.com/go-kit/kit/log"
"github.com/go-kit/kit/log/level"
"github.com/pkg/errors"
"github.com/prometheus/common/model"
apiv1 "k8s.io/api/core/v1"
metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
"k8s.io/client-go/tools/cache"
"k8s.io/client-go/util/workqueue"
"github.com/prometheus/prometheus/discovery/targetgroup"
"github.com/prometheus/prometheus/util/strutil"
)
// Pod discovers new pod targets.
type Pod struct {
informer cache.SharedInformer
store cache.Store
logger log.Logger
queue *workqueue.Type
}
// NewPod creates a new pod discovery.
func NewPod(l log.Logger, pods cache.SharedInformer) *Pod {
if l == nil {
l = log.NewNopLogger()
}
p := &Pod{
informer: pods,
store: pods.GetStore(),
logger: l,
queue: workqueue.NewNamed("pod"),
}
p.informer.AddEventHandler(cache.ResourceEventHandlerFuncs{
AddFunc: func(o interface{}) {
eventCount.WithLabelValues("pod", "add").Inc()
p.enqueue(o)
},
DeleteFunc: func(o interface{}) {
eventCount.WithLabelValues("pod", "delete").Inc()
p.enqueue(o)
},
UpdateFunc: func(_, o interface{}) {
eventCount.WithLabelValues("pod", "update").Inc()
p.enqueue(o)
},
})
return p
}
func (p *Pod) enqueue(obj interface{}) {
key, err := cache.DeletionHandlingMetaNamespaceKeyFunc(obj)
if err != nil {
return
}
p.queue.Add(key)
}
// Run implements the Discoverer interface.
func (p *Pod) Run(ctx context.Context, ch chan<- []*targetgroup.Group) {
defer p.queue.ShutDown()
if !cache.WaitForCacheSync(ctx.Done(), p.informer.HasSynced) {
level.Error(p.logger).Log("msg", "pod informer unable to sync cache")
return
}
go func() {
for p.process(ctx, ch) {
}
}()
// Block until the target provider is explicitly canceled.
<-ctx.Done()
}
func (p *Pod) process(ctx context.Context, ch chan<- []*targetgroup.Group) bool {
keyObj, quit := p.queue.Get()
if quit {
return false
}
defer p.queue.Done(keyObj)
key := keyObj.(string)
namespace, name, err := cache.SplitMetaNamespaceKey(key)
if err != nil {
return true
}
o, exists, err := p.store.GetByKey(key)
if err != nil {
return true
}
if !exists {
send(ctx, p.logger, RolePod, ch, &targetgroup.Group{Source: podSourceFromNamespaceAndName(namespace, name)})
return true
}
eps, err := convertToPod(o)
if err != nil {
level.Error(p.logger).Log("msg", "converting to Pod object failed", "err", err)
return true
}
send(ctx, p.logger, RolePod, ch, p.buildPod(eps))
return true
}
func convertToPod(o interface{}) (*apiv1.Pod, error) {
pod, ok := o.(*apiv1.Pod)
if ok {
return pod, nil
}
return nil, errors.Errorf("received unexpected object: %v", o)
}
const (
podNameLabel = metaLabelPrefix + "pod_name"
podIPLabel = metaLabelPrefix + "pod_ip"
podContainerNameLabel = metaLabelPrefix + "pod_container_name"
podContainerPortNameLabel = metaLabelPrefix + "pod_container_port_name"
podContainerPortNumberLabel = metaLabelPrefix + "pod_container_port_number"
podContainerPortProtocolLabel = metaLabelPrefix + "pod_container_port_protocol"
podReadyLabel = metaLabelPrefix + "pod_ready"
podPhaseLabel = metaLabelPrefix + "pod_phase"
podLabelPrefix = metaLabelPrefix + "pod_label_"
podAnnotationPrefix = metaLabelPrefix + "pod_annotation_"
podNodeNameLabel = metaLabelPrefix + "pod_node_name"
podHostIPLabel = metaLabelPrefix + "pod_host_ip"
podUID = metaLabelPrefix + "pod_uid"
podControllerKind = metaLabelPrefix + "pod_controller_kind"
podControllerName = metaLabelPrefix + "pod_controller_name"
)
// GetControllerOf returns a pointer to a copy of the controllerRef if controllee has a controller
// https://github.com/kubernetes/apimachinery/blob/cd2cae2b39fa57e8063fa1f5f13cfe9862db3d41/pkg/apis/meta/v1/controller_ref.go
func GetControllerOf(controllee metav1.Object) *metav1.OwnerReference {
for _, ref := range controllee.GetOwnerReferences() {
if ref.Controller != nil && *ref.Controller {
return &ref
}
}
return nil
}
func podLabels(pod *apiv1.Pod) model.LabelSet {
ls := model.LabelSet{
podNameLabel: lv(pod.ObjectMeta.Name),
podIPLabel: lv(pod.Status.PodIP),
podReadyLabel: podReady(pod),
podPhaseLabel: lv(string(pod.Status.Phase)),
podNodeNameLabel: lv(pod.Spec.NodeName),
podHostIPLabel: lv(pod.Status.HostIP),
podUID: lv(string(pod.ObjectMeta.UID)),
}
createdBy := GetControllerOf(pod)
if createdBy != nil {
if createdBy.Kind != "" {
ls[podControllerKind] = lv(createdBy.Kind)
}
if createdBy.Name != "" {
ls[podControllerName] = lv(createdBy.Name)
}
}
for k, v := range pod.Labels {
ln := strutil.SanitizeLabelName(podLabelPrefix + k)
ls[model.LabelName(ln)] = lv(v)
}
for k, v := range pod.Annotations {
ln := strutil.SanitizeLabelName(podAnnotationPrefix + k)
ls[model.LabelName(ln)] = lv(v)
}
return ls
}
func (p *Pod) buildPod(pod *apiv1.Pod) *targetgroup.Group {
tg := &targetgroup.Group{
Source: podSource(pod),
}
// PodIP can be empty when a pod is starting or has been evicted.
if len(pod.Status.PodIP) == 0 {
return tg
}
tg.Labels = podLabels(pod)
tg.Labels[namespaceLabel] = lv(pod.Namespace)
for _, c := range pod.Spec.Containers {
// If no ports are defined for the container, create an anonymous
// target per container.
if len(c.Ports) == 0 {
// We don't have a port so we just set the address label to the pod IP.
// The user has to add a port manually.
tg.Targets = append(tg.Targets, model.LabelSet{
model.AddressLabel: lv(pod.Status.PodIP),
podContainerNameLabel: lv(c.Name),
})
continue
}
// Otherwise create one target for each container/port combination.
for _, port := range c.Ports {
ports := strconv.FormatUint(uint64(port.ContainerPort), 10)
addr := net.JoinHostPort(pod.Status.PodIP, ports)
tg.Targets = append(tg.Targets, model.LabelSet{
model.AddressLabel: lv(addr),
podContainerNameLabel: lv(c.Name),
podContainerPortNumberLabel: lv(ports),
podContainerPortNameLabel: lv(port.Name),
podContainerPortProtocolLabel: lv(string(port.Protocol)),
})
}
}
return tg
}
func podSource(pod *apiv1.Pod) string {
return podSourceFromNamespaceAndName(pod.Namespace, pod.Name)
}
func podSourceFromNamespaceAndName(namespace, name string) string {
return "pod/" + namespace + "/" + name
}
func podReady(pod *apiv1.Pod) model.LabelValue {
for _, cond := range pod.Status.Conditions {
if cond.Type == apiv1.PodReady {
return lv(strings.ToLower(string(cond.Status)))
}
}
return lv(strings.ToLower(string(apiv1.ConditionUnknown)))
}