blob: 67973c514a664a7938cc64ac6ee05ded5f0107cd [file] [log] [blame]
// Copyright 2015 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package main
import (
"context"
"errors"
"fmt"
"io"
"log"
"sort"
"strconv"
"strings"
"sync"
"time"
"golang.org/x/build/buildlet"
"golang.org/x/build/dashboard"
"golang.org/x/build/kubernetes"
"golang.org/x/build/kubernetes/api"
"golang.org/x/build/kubernetes/gke"
container "google.golang.org/api/container/v1"
)
/*
This file implements the Kubernetes-based buildlet pool.
*/
// Initialized by initKube:
var (
buildletsKubeClient *kubernetes.Client // for "buildlets" cluster
goKubeClient *kubernetes.Client // for "go" cluster (misc jobs)
kubeErr error
registryPrefix = "gcr.io"
kubeCluster *container.Cluster
)
// initGCE must be called before initKube
func initKube() error {
if buildEnv.KubeBuild.MaxNodes == 0 {
return errors.New("Kubernetes builders disabled due to KubeBuild.MaxNodes == 0")
}
// projectID was set by initGCE
registryPrefix += "/" + buildEnv.ProjectName
if !hasCloudPlatformScope() {
return errors.New("coordinator not running with access to the Cloud Platform scope.")
}
ctx, cancel := context.WithTimeout(context.Background(), 1*time.Minute)
defer cancel() // ctx is only used for discovery and connect; not retained.
var err error
buildletsKubeClient, err = gke.NewClient(ctx,
buildEnv.KubeBuild.Name,
gke.OptZone(buildEnv.Zone),
gke.OptProject(buildEnv.ProjectName),
gke.OptTokenSource(tokenSource))
if err != nil {
return err
}
goKubeClient, err = gke.NewClient(ctx,
buildEnv.KubeTools.Name,
gke.OptZone(buildEnv.Zone),
gke.OptProject(buildEnv.ProjectName),
gke.OptTokenSource(tokenSource))
if err != nil {
return err
}
go kubePool.pollCapacityLoop()
return nil
}
// kubeBuildletPool is the Kubernetes buildlet pool.
type kubeBuildletPool struct {
mu sync.Mutex // guards all following
pods map[string]podHistory // pod instance name -> podHistory
clusterResources *kubeResource // cpu and memory resources of the Kubernetes cluster
pendingResources *kubeResource // cpu and memory resources waiting to be scheduled
runningResources *kubeResource // cpu and memory resources already running (periodically updated from API)
}
var kubePool = &kubeBuildletPool{
clusterResources: &kubeResource{
cpu: api.NewQuantity(0, api.DecimalSI),
memory: api.NewQuantity(0, api.BinarySI),
},
pendingResources: &kubeResource{
cpu: api.NewQuantity(0, api.DecimalSI),
memory: api.NewQuantity(0, api.BinarySI),
},
runningResources: &kubeResource{
cpu: api.NewQuantity(0, api.DecimalSI),
memory: api.NewQuantity(0, api.BinarySI),
},
}
type kubeResource struct {
cpu *api.Quantity
memory *api.Quantity
}
type podHistory struct {
requestedAt time.Time
readyAt time.Time
deletedAt time.Time
}
func (p podHistory) String() string {
return fmt.Sprintf("requested at %v, ready at %v, deleted at %v", p.requestedAt, p.readyAt, p.deletedAt)
}
func (p *kubeBuildletPool) pollCapacityLoop() {
ctx := context.Background()
for {
p.pollCapacity(ctx)
time.Sleep(15 * time.Second)
}
}
func (p *kubeBuildletPool) pollCapacity(ctx context.Context) {
nodes, err := buildletsKubeClient.GetNodes(ctx)
if err != nil {
log.Printf("failed to retrieve nodes to calculate cluster capacity for %s/%s: %v", buildEnv.ProjectName, buildEnv.Region(), err)
return
}
pods, err := buildletsKubeClient.GetPods(ctx)
if err != nil {
log.Printf("failed to retrieve pods to calculate cluster capacity for %s/%s: %v", buildEnv.ProjectName, buildEnv.Region(), err)
return
}
p.mu.Lock()
// Calculate the total provisioned, pending, and running CPU and memory
// in the cluster
provisioned := &kubeResource{
cpu: api.NewQuantity(0, api.DecimalSI),
memory: api.NewQuantity(0, api.BinarySI),
}
running := &kubeResource{
cpu: api.NewQuantity(0, api.DecimalSI),
memory: api.NewQuantity(0, api.BinarySI),
}
pending := &kubeResource{
cpu: api.NewQuantity(0, api.DecimalSI),
memory: api.NewQuantity(0, api.BinarySI),
}
// Resources used by running and pending pods
var resourceCounter *kubeResource
for _, pod := range pods {
switch pod.Status.Phase {
case api.PodPending:
resourceCounter = pending
case api.PodRunning:
resourceCounter = running
case api.PodSucceeded:
// TODO(bradfitz,evanbrown): this was spamming
// logs a lot. Don't count these resources, I
// assume. We weren't before (when the
// log.Printf below was firing) anyway.
continue
default:
log.Printf("Pod in unknown state (%q); ignoring", pod.Status.Phase)
continue
}
for _, c := range pod.Spec.Containers {
// The Kubernetes API rarely, but can, return a response
// with an empty Requests map. Check to be sure...
if _, ok := c.Resources.Requests[api.ResourceCPU]; ok {
resourceCounter.cpu.Add(c.Resources.Requests[api.ResourceCPU])
}
if _, ok := c.Resources.Requests[api.ResourceMemory]; ok {
resourceCounter.memory.Add(c.Resources.Requests[api.ResourceMemory])
}
}
}
p.runningResources = running
p.pendingResources = pending
// Resources provisioned to the cluster
for _, n := range nodes {
provisioned.cpu.Add(n.Status.Capacity[api.ResourceCPU])
provisioned.memory.Add(n.Status.Capacity[api.ResourceMemory])
}
p.clusterResources = provisioned
p.mu.Unlock()
}
func (p *kubeBuildletPool) GetBuildlet(ctx context.Context, hostType string, lg logger) (*buildlet.Client, error) {
hconf, ok := dashboard.Hosts[hostType]
if !ok || !hconf.IsKube() {
return nil, fmt.Errorf("kubepool: invalid host type %q", hostType)
}
if kubeErr != nil {
return nil, kubeErr
}
if buildletsKubeClient == nil {
panic("expect non-nil buildletsKubeClient")
}
deleteIn, ok := ctx.Value(buildletTimeoutOpt{}).(time.Duration)
if !ok {
deleteIn = podDeleteTimeout
}
podName := "buildlet-" + strings.TrimPrefix(hostType, "host-") + "-rn" + randHex(7)
// Get an estimate for when the pod will be started/running and set
// the context timeout based on that
var needDelete bool
lg.logEventTime("creating_kube_pod", podName)
log.Printf("Creating Kubernetes pod %q for %s", podName, hostType)
bc, err := buildlet.StartPod(ctx, buildletsKubeClient, podName, hostType, buildlet.PodOpts{
ProjectID: buildEnv.ProjectName,
ImageRegistry: registryPrefix,
Description: fmt.Sprintf("Go Builder for %s", hostType),
DeleteIn: deleteIn,
OnPodCreating: func() {
lg.logEventTime("pod_creating")
p.setPodUsed(podName, true)
p.updatePodHistory(podName, podHistory{requestedAt: time.Now()})
needDelete = true
},
OnPodCreated: func() {
lg.logEventTime("pod_created")
p.updatePodHistory(podName, podHistory{readyAt: time.Now()})
},
OnGotPodInfo: func() {
lg.logEventTime("got_pod_info", "waiting_for_buildlet...")
},
})
if err != nil {
lg.logEventTime("kube_buildlet_create_failure", fmt.Sprintf("%s: %v", podName, err))
if needDelete {
log.Printf("Deleting failed pod %q", podName)
if err := buildletsKubeClient.DeletePod(context.Background(), podName); err != nil {
log.Printf("Error deleting pod %q: %v", podName, err)
}
p.setPodUsed(podName, false)
}
return nil, err
}
bc.SetDescription("Kube Pod: " + podName)
// The build's context will be canceled when the build completes (successfully
// or not), or if the buildlet becomes unavailable. In any case, delete the pod
// running the buildlet.
go func() {
<-ctx.Done()
log.Printf("Deleting pod %q after build context completed", podName)
// Giving DeletePod a new context here as the build ctx has been canceled
buildletsKubeClient.DeletePod(context.Background(), podName)
p.setPodUsed(podName, false)
}()
return bc, nil
}
func (p *kubeBuildletPool) WriteHTMLStatus(w io.Writer) {
fmt.Fprintf(w, "<b>Kubernetes pool</b> capacity: %s", p.capacityString())
const show = 6 // must be even
active := p.podsActive()
if len(active) > 0 {
fmt.Fprintf(w, "<ul>")
for i, pod := range active {
if i < show/2 || i >= len(active)-(show/2) {
fmt.Fprintf(w, "<li>%v, %v</li>\n", pod.name, time.Since(pod.creation))
} else if i == show/2 {
fmt.Fprintf(w, "<li>... %d of %d total omitted ...</li>\n", len(active)-show, len(active))
}
}
fmt.Fprintf(w, "</ul>")
}
}
func (p *kubeBuildletPool) capacityString() string {
p.mu.Lock()
defer p.mu.Unlock()
return fmt.Sprintf("<ul><li>%v CPUs running, %v CPUs pending, %v total CPUs in cluster</li><li>%v memory running, %v memory pending, %v total memory in cluster</li></ul>",
p.runningResources.cpu, p.pendingResources.cpu, p.clusterResources.cpu,
p.runningResources.memory, p.pendingResources.memory, p.clusterResources.memory)
}
func (p *kubeBuildletPool) setPodUsed(podName string, used bool) {
p.mu.Lock()
defer p.mu.Unlock()
if p.pods == nil {
p.pods = make(map[string]podHistory)
}
if used {
p.pods[podName] = podHistory{requestedAt: time.Now()}
} else {
p.pods[podName] = podHistory{deletedAt: time.Now()}
// TODO(evanbrown): log this podHistory data for analytics purposes before deleting
delete(p.pods, podName)
}
}
func (p *kubeBuildletPool) updatePodHistory(podName string, updatedHistory podHistory) error {
p.mu.Lock()
defer p.mu.Unlock()
ph, ok := p.pods[podName]
if !ok {
return fmt.Errorf("pod %q does not exist", podName)
}
if !updatedHistory.readyAt.IsZero() {
ph.readyAt = updatedHistory.readyAt
}
if !updatedHistory.requestedAt.IsZero() {
ph.requestedAt = updatedHistory.requestedAt
}
if !updatedHistory.deletedAt.IsZero() {
ph.deletedAt = updatedHistory.deletedAt
}
p.pods[podName] = ph
return nil
}
func (p *kubeBuildletPool) podUsed(podName string) bool {
p.mu.Lock()
defer p.mu.Unlock()
_, ok := p.pods[podName]
return ok
}
func (p *kubeBuildletPool) podsActive() (ret []resourceTime) {
p.mu.Lock()
defer p.mu.Unlock()
for name, ph := range p.pods {
ret = append(ret, resourceTime{
name: name,
creation: ph.requestedAt,
})
}
sort.Sort(byCreationTime(ret))
return ret
}
func (p *kubeBuildletPool) String() string {
p.mu.Lock()
inUse := 0
total := 0
// ...
p.mu.Unlock()
return fmt.Sprintf("Kubernetes pool capacity: %d/%d", inUse, total)
}
// cleanUpOldPods loops forever and periodically enumerates pods
// and deletes those which have expired.
//
// A Pod is considered expired if it has a "delete-at" metadata
// attribute having a unix timestamp before the current time.
//
// This is the safety mechanism to delete pods which stray from the
// normal deleting process. Pods are created to run a single build and
// should be shut down by a controlling process. Due to various types
// of failures, they might get stranded. To prevent them from getting
// stranded and wasting resources forever, we instead set the
// "delete-at" metadata attribute on them when created to some time
// that's well beyond their expected lifetime.
func (p *kubeBuildletPool) cleanUpOldPodsLoop(ctx context.Context) {
if buildletsKubeClient == nil {
log.Printf("cleanUpOldPods: no buildletsKubeClient configured; aborting.")
return
}
for {
ctx, cancel := context.WithTimeout(ctx, 5*time.Minute)
p.cleanUpOldPods(ctx)
cancel()
time.Sleep(time.Minute)
}
}
func (p *kubeBuildletPool) cleanUpOldPods(ctx context.Context) {
pods, err := buildletsKubeClient.GetPods(ctx)
if err != nil {
log.Printf("cleanUpOldPods: error getting pods: %v", err)
return
}
var stats struct {
Pods int
WithAttr int
WithDelete int
DeletedOld int // even if failed to delete
StillUsed int
DeletedOldGen int // even if failed to delete
}
for _, pod := range pods {
if pod.ObjectMeta.Annotations == nil {
// Defensive. Not seen in practice.
continue
}
stats.Pods++
sawDeleteAt := false
stats.WithAttr++
for k, v := range pod.ObjectMeta.Annotations {
if k == "delete-at" {
stats.WithDelete++
sawDeleteAt = true
if v == "" {
log.Printf("cleanUpOldPods: missing delete-at value; ignoring")
continue
}
unixDeadline, err := strconv.ParseInt(v, 10, 64)
if err != nil {
log.Printf("cleanUpOldPods: invalid delete-at value %q seen; ignoring", v)
}
if err == nil && time.Now().Unix() > unixDeadline {
stats.DeletedOld++
log.Printf("cleanUpOldPods: Deleting expired pod %q in zone %q ...", pod.Name, buildEnv.Zone)
err = buildletsKubeClient.DeletePod(ctx, pod.Name)
if err != nil {
log.Printf("cleanUpOldPods: problem deleting old pod %q: %v", pod.Name, err)
}
}
}
}
// Delete buildlets (things we made) from previous
// generations. Only deleting things starting with "buildlet-"
// is a historical restriction, but still fine for paranoia.
if sawDeleteAt && strings.HasPrefix(pod.Name, "buildlet-") {
if p.podUsed(pod.Name) {
stats.StillUsed++
} else {
stats.DeletedOldGen++
log.Printf("cleanUpOldPods: deleting pod %q from an earlier coordinator generation ...", pod.Name)
err = buildletsKubeClient.DeletePod(ctx, pod.Name)
if err != nil {
log.Printf("cleanUpOldPods: problem deleting pod: %v", err)
}
}
}
}
if stats.Pods > 0 {
log.Printf("cleanUpOldPods: loop stats: %+v", stats)
}
}
func hasCloudPlatformScope() bool {
return hasScope(container.CloudPlatformScope)
}