kubernetes/pkg/standalone/standalone.go
Filipe Brandenburger 79ff06ffa1 Fix comparison of EtcdClient to nil so that it does not run into the pointer vs. interface issue
This is a partial rollback of commit 6e6f465a36 ("Fix a crash for
kubelet when without EtcdClient") in which we used the `reflect` module
to inspect that the pointer stored inside the interface was `nil`, but
as pointed out by @lavalamp, the correct solution is to make the
function return the interface type, in which case a `return nil` will
return the interface nil and not a nil pointer that turns into a non-nil
value when coerced into an interface.

For more details, see http://golang.org/doc/faq#nil_error and the
discussion in PR #3356.

Tested by installing a kubelet built from head with this patch into a
containervm instance and confirming it did not crash on standalone.go.
Confirmed that by only removing the `reflect.IsNil()` comparison but not
changing the return type of `EtcdClientOrDie()` did indeed cause that
same crash, so changing the return type does indeed fix the issue.

Signed-off-by: Filipe Brandenburger <filbranden@google.com>
2015-01-16 16:43:05 -08:00

304 lines
9.5 KiB
Go

/*
Copyright 2014 Google Inc. All rights reserved.
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 standalone
import (
"fmt"
"net"
"net/http"
"time"
"github.com/GoogleCloudPlatform/kubernetes/pkg/api"
"github.com/GoogleCloudPlatform/kubernetes/pkg/api/resource"
"github.com/GoogleCloudPlatform/kubernetes/pkg/apiserver"
"github.com/GoogleCloudPlatform/kubernetes/pkg/client"
"github.com/GoogleCloudPlatform/kubernetes/pkg/clientauth"
nodeControllerPkg "github.com/GoogleCloudPlatform/kubernetes/pkg/cloudprovider/controller"
"github.com/GoogleCloudPlatform/kubernetes/pkg/controller"
"github.com/GoogleCloudPlatform/kubernetes/pkg/kubelet"
"github.com/GoogleCloudPlatform/kubernetes/pkg/kubelet/config"
"github.com/GoogleCloudPlatform/kubernetes/pkg/kubelet/dockertools"
"github.com/GoogleCloudPlatform/kubernetes/pkg/master"
"github.com/GoogleCloudPlatform/kubernetes/pkg/service"
"github.com/GoogleCloudPlatform/kubernetes/pkg/tools"
"github.com/GoogleCloudPlatform/kubernetes/pkg/util"
"github.com/GoogleCloudPlatform/kubernetes/plugin/pkg/scheduler"
_ "github.com/GoogleCloudPlatform/kubernetes/plugin/pkg/scheduler/algorithmprovider"
"github.com/GoogleCloudPlatform/kubernetes/plugin/pkg/scheduler/factory"
"github.com/golang/glog"
)
type delegateHandler struct {
delegate http.Handler
}
func (h *delegateHandler) ServeHTTP(w http.ResponseWriter, req *http.Request) {
if h.delegate != nil {
h.delegate.ServeHTTP(w, req)
return
}
w.WriteHeader(http.StatusNotFound)
}
// TODO: replace this with clientcmd
func GetAPIServerClient(authPath string, apiServerList util.StringList) (*client.Client, error) {
authInfo, err := clientauth.LoadFromFile(authPath)
if err != nil {
return nil, err
}
clientConfig, err := authInfo.MergeWithConfig(client.Config{})
if err != nil {
return nil, err
}
if len(apiServerList) < 1 {
return nil, fmt.Errorf("no api servers specified.")
}
// TODO: adapt Kube client to support LB over several servers
if len(apiServerList) > 1 {
glog.Infof("Mulitple api servers specified. Picking first one")
}
clientConfig.Host = apiServerList[0]
c, err := client.New(&clientConfig)
if err != nil {
return nil, err
}
return c, nil
}
// RunApiServer starts an API server in a go routine.
func RunApiServer(cl *client.Client, etcdClient tools.EtcdClient, addr string, port int, masterServiceNamespace string) {
handler := delegateHandler{}
helper, err := master.NewEtcdHelper(etcdClient, "")
if err != nil {
glog.Fatalf("Unable to get etcd helper: %v", err)
}
// Create a master and install handlers into mux.
m := master.New(&master.Config{
Client: cl,
EtcdHelper: helper,
KubeletClient: &client.HTTPKubeletClient{
Client: http.DefaultClient,
Port: 10250,
},
EnableLogsSupport: false,
EnableSwaggerSupport: true,
APIPrefix: "/api",
Authorizer: apiserver.NewAlwaysAllowAuthorizer(),
ReadWritePort: port,
ReadOnlyPort: port,
PublicAddress: addr,
MasterServiceNamespace: masterServiceNamespace,
})
handler.delegate = m.InsecureHandler
go http.ListenAndServe(fmt.Sprintf("%s:%d", addr, port), &handler)
}
// RunScheduler starts up a scheduler in it's own goroutine
func RunScheduler(cl *client.Client) {
// Scheduler
schedulerConfigFactory := factory.NewConfigFactory(cl)
schedulerConfig, err := schedulerConfigFactory.Create()
if err != nil {
glog.Fatalf("Couldn't create scheduler config: %v", err)
}
scheduler.New(schedulerConfig).Run()
}
// RunControllerManager starts a controller
func RunControllerManager(machineList []string, cl *client.Client, nodeMilliCPU, nodeMemory int64) {
nodeResources := &api.NodeResources{
Capacity: api.ResourceList{
api.ResourceCPU: *resource.NewMilliQuantity(nodeMilliCPU, resource.DecimalSI),
api.ResourceMemory: *resource.NewQuantity(nodeMemory, resource.BinarySI),
},
}
nodeController := nodeControllerPkg.NewNodeController(nil, "", machineList, nodeResources, cl)
nodeController.Run(10 * time.Second)
endpoints := service.NewEndpointController(cl)
go util.Forever(func() { endpoints.SyncServiceEndpoints() }, time.Second*10)
controllerManager := controller.NewReplicationManager(cl)
controllerManager.Run(10 * time.Second)
}
// SimpleRunKubelet is a simple way to start a Kubelet talking to dockerEndpoint, using an etcdClient.
// Under the hood it calls RunKubelet (below)
func SimpleRunKubelet(client *client.Client,
etcdClient tools.EtcdClient,
dockerClient dockertools.DockerInterface,
hostname, rootDir, manifestURL, address string,
port uint,
masterServiceNamespace string) {
kcfg := KubeletConfig{
KubeClient: client,
EtcdClient: etcdClient,
DockerClient: dockerClient,
HostnameOverride: hostname,
RootDirectory: rootDir,
ManifestURL: manifestURL,
NetworkContainerImage: kubelet.NetworkContainerImage,
Port: port,
Address: util.IP(net.ParseIP(address)),
EnableServer: true,
EnableDebuggingHandlers: true,
SyncFrequency: 3 * time.Second,
MinimumGCAge: 10 * time.Second,
MaxContainerCount: 5,
MasterServiceNamespace: masterServiceNamespace,
}
RunKubelet(&kcfg)
}
// RunKubelet is responsible for setting up and running a kubelet. It is used in three different applications:
// 1 Integration tests
// 2 Kubelet binary
// 3 Standalone 'kubernetes' binary
// Eventually, #2 will be replaced with instances of #3
func RunKubelet(kcfg *KubeletConfig) {
kcfg.Hostname = util.GetHostname(kcfg.HostnameOverride)
if kcfg.KubeClient != nil {
kubelet.SetupEventSending(kcfg.KubeClient, kcfg.Hostname)
} else {
glog.Infof("No api server defined - no events will be sent.")
}
kubelet.SetupLogging()
kubelet.SetupCapabilities(kcfg.AllowPrivileged)
cfg := makePodSourceConfig(kcfg)
k, err := createAndInitKubelet(kcfg, cfg)
if err != nil {
glog.Errorf("Failed to create kubelet: %s", err)
return
}
// process pods and exit.
if kcfg.Runonce {
if _, err := k.RunOnce(cfg.Updates()); err != nil {
glog.Errorf("--runonce failed: %v", err)
}
} else {
startKubelet(k, cfg, kcfg)
}
}
func startKubelet(k *kubelet.Kubelet, cfg *config.PodConfig, kc *KubeletConfig) {
// start the kubelet
go util.Forever(func() { k.Run(cfg.Updates()) }, 0)
// start the kubelet server
if kc.EnableServer {
go util.Forever(func() {
kubelet.ListenAndServeKubeletServer(k, net.IP(kc.Address), kc.Port, kc.EnableDebuggingHandlers)
}, 0)
}
}
func makePodSourceConfig(kc *KubeletConfig) *config.PodConfig {
// source of all configuration
cfg := config.NewPodConfig(config.PodConfigNotificationSnapshotAndUpdates)
// define file config source
if kc.ConfigFile != "" {
glog.Infof("Adding manifest file: %v", kc.ConfigFile)
config.NewSourceFile(kc.ConfigFile, kc.FileCheckFrequency, cfg.Channel(kubelet.FileSource))
}
// define url config source
if kc.ManifestURL != "" {
glog.Infof("Adding manifest url: %v", kc.ManifestURL)
config.NewSourceURL(kc.ManifestURL, kc.HttpCheckFrequency, cfg.Channel(kubelet.HTTPSource))
}
if kc.EtcdClient != nil {
glog.Infof("Watching for etcd configs at %v", kc.EtcdClient.GetCluster())
config.NewSourceEtcd(config.EtcdKeyForHost(kc.Hostname), kc.EtcdClient, cfg.Channel(kubelet.EtcdSource))
}
if kc.KubeClient != nil {
glog.Infof("Watching apiserver")
config.NewSourceApiserver(kc.KubeClient, kc.Hostname, cfg.Channel(kubelet.ApiserverSource))
}
return cfg
}
type KubeletConfig struct {
EtcdClient tools.EtcdClient
KubeClient *client.Client
DockerClient dockertools.DockerInterface
CAdvisorPort uint
Address util.IP
AllowPrivileged bool
HostnameOverride string
RootDirectory string
ConfigFile string
ManifestURL string
FileCheckFrequency time.Duration
HttpCheckFrequency time.Duration
Hostname string
NetworkContainerImage string
SyncFrequency time.Duration
RegistryPullQPS float64
RegistryBurst int
MinimumGCAge time.Duration
MaxContainerCount int
ClusterDomain string
ClusterDNS util.IP
EnableServer bool
EnableDebuggingHandlers bool
Port uint
Runonce bool
MasterServiceNamespace string
}
func createAndInitKubelet(kc *KubeletConfig, pc *config.PodConfig) (*kubelet.Kubelet, error) {
// TODO: block until all sources have delivered at least one update to the channel, or break the sync loop
// up into "per source" synchronizations
k, err := kubelet.NewMainKubelet(
kc.Hostname,
kc.DockerClient,
kc.EtcdClient,
kc.KubeClient,
kc.RootDirectory,
kc.NetworkContainerImage,
kc.SyncFrequency,
float32(kc.RegistryPullQPS),
kc.RegistryBurst,
kc.MinimumGCAge,
kc.MaxContainerCount,
pc.IsSourceSeen,
kc.ClusterDomain,
net.IP(kc.ClusterDNS),
kc.MasterServiceNamespace)
if err != nil {
return nil, err
}
k.BirthCry()
go k.GarbageCollectLoop()
go kubelet.MonitorCAdvisor(k, kc.CAdvisorPort)
kubelet.InitHealthChecking(k)
return k, nil
}