8180536bed
Revert "Merge pull request #51857 from kubernetes/revert-51307-kc-type-refactor" This reverts commit9d27d92420, reversing changes made to2e69d4e625. See original: #51307 We punted this from 1.8 so it could go through an API review. The point of this PR is that we are trying to stabilize the kubeletconfig API so that we can move it out of alpha, and unblock features like Dynamic Kubelet Config, Kubelet loading its initial config from a file instead of flags, kubeadm and other install tools having a versioned API to rely on, etc. We shouldn't rev the version without both removing all the deprecated junk from the KubeletConfiguration struct, and without (at least temporarily) removing all of the fields that have "Experimental" in their names. It wouldn't make sense to lock in to deprecated fields. "Experimental" fields can be audited on a 1-by-1 basis after this PR, and if found to be stable (or sufficiently alpha-gated), can be restored to the KubeletConfiguration without the "Experimental" prefix.
110 lines
3.6 KiB
Go
110 lines
3.6 KiB
Go
/*
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Copyright 2014 The Kubernetes Authors.
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Licensed under the Apache License, Version 2.0 (the "License");
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you may not use this file except in compliance with the License.
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You may obtain a copy of the License at
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http://www.apache.org/licenses/LICENSE-2.0
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Unless required by applicable law or agreed to in writing, software
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distributed under the License is distributed on an "AS IS" BASIS,
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WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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See the License for the specific language governing permissions and
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limitations under the License.
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*/
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// The kubelet binary is responsible for maintaining a set of containers on a particular host VM.
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// It syncs data from both configuration file(s) as well as from a quorum of etcd servers.
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// It then queries Docker to see what is currently running. It synchronizes the configuration data,
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// with the running set of containers by starting or stopping Docker containers.
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package main
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import (
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"fmt"
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"os"
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"github.com/spf13/pflag"
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utilfeature "k8s.io/apiserver/pkg/util/feature"
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"k8s.io/apiserver/pkg/util/flag"
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"k8s.io/apiserver/pkg/util/logs"
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"k8s.io/kubernetes/cmd/kubelet/app"
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"k8s.io/kubernetes/cmd/kubelet/app/options"
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_ "k8s.io/kubernetes/pkg/client/metrics/prometheus" // for client metric registration
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_ "k8s.io/kubernetes/pkg/version/prometheus" // for version metric registration
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"k8s.io/kubernetes/pkg/version/verflag"
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)
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func die(err error) {
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fmt.Fprintf(os.Stderr, "error: %v\n", err)
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os.Exit(1)
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}
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func main() {
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// construct KubeletFlags object and register command line flags mapping
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kubeletFlags := options.NewKubeletFlags()
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kubeletFlags.AddFlags(pflag.CommandLine)
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// construct KubeletConfiguration object and register command line flags mapping
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defaultConfig, err := options.NewKubeletConfiguration()
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if err != nil {
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die(err)
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}
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options.AddKubeletConfigFlags(pflag.CommandLine, defaultConfig)
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// parse the command line flags into the respective objects
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flag.InitFlags()
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// initialize logging and defer flush
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logs.InitLogs()
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defer logs.FlushLogs()
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// short-circuit on verflag
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verflag.PrintAndExitIfRequested()
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// TODO(mtaufen): won't need this this once dynamic config is GA
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// set feature gates so we can check if dynamic config is enabled
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if err := utilfeature.DefaultFeatureGate.SetFromMap(defaultConfig.FeatureGates); err != nil {
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die(err)
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}
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// validate the initial KubeletFlags, to make sure the dynamic-config-related flags aren't used unless the feature gate is on
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if err := options.ValidateKubeletFlags(kubeletFlags); err != nil {
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die(err)
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}
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// bootstrap the kubelet config controller, app.BootstrapKubeletConfigController will check
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// feature gates and only turn on relevant parts of the controller
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kubeletConfig, kubeletConfigController, err := app.BootstrapKubeletConfigController(
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defaultConfig, kubeletFlags.InitConfigDir, kubeletFlags.DynamicConfigDir)
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if err != nil {
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die(err)
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}
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// construct a KubeletServer from kubeletFlags and kubeletConfig
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kubeletServer := &options.KubeletServer{
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KubeletFlags: *kubeletFlags,
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KubeletConfiguration: *kubeletConfig,
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}
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// use kubeletServer to construct the default KubeletDeps
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kubeletDeps, err := app.UnsecuredDependencies(kubeletServer)
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if err != nil {
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die(err)
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}
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// add the kubelet config controller to kubeletDeps
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kubeletDeps.KubeletConfigController = kubeletConfigController
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// start the experimental docker shim, if enabled
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if kubeletFlags.ExperimentalDockershim {
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if err := app.RunDockershim(kubeletFlags, kubeletConfig); err != nil {
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die(err)
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}
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}
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// run the kubelet
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if err := app.Run(kubeletServer, kubeletDeps); err != nil {
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die(err)
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}
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}
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