oom_watcher_linux.go

Documentation: k8s.io/kubernetes/pkg/kubelet/oom

     1  //go:build linux
     2  // +build linux
     3  
     4  /*
     5  Copyright 2015 The Kubernetes Authors.
     6  
     7  Licensed under the Apache License, Version 2.0 (the "License");
     8  you may not use this file except in compliance with the License.
     9  You may obtain a copy of the License at
    10  
    11      http://www.apache.org/licenses/LICENSE-2.0
    12  
    13  Unless required by applicable law or agreed to in writing, software
    14  distributed under the License is distributed on an "AS IS" BASIS,
    15  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    16  See the License for the specific language governing permissions and
    17  limitations under the License.
    18  */
    19  
    20  package oom
    21  
    22  import (
    23  	"fmt"
    24  
    25  	v1 "k8s.io/api/core/v1"
    26  	"k8s.io/apimachinery/pkg/util/runtime"
    27  	"k8s.io/client-go/tools/record"
    28  	"k8s.io/klog/v2"
    29  
    30  	"github.com/google/cadvisor/utils/oomparser"
    31  )
    32  
    33  type streamer interface {
    34  	StreamOoms(chan<- *oomparser.OomInstance)
    35  }
    36  
    37  var _ streamer = &oomparser.OomParser{}
    38  
    39  type realWatcher struct {
    40  	recorder    record.EventRecorder
    41  	oomStreamer streamer
    42  }
    43  
    44  var _ Watcher = &realWatcher{}
    45  
    46  // NewWatcher creates and initializes a OOMWatcher backed by Cadvisor as
    47  // the oom streamer.
    48  func NewWatcher(recorder record.EventRecorder) (Watcher, error) {
    49  	// for test purpose
    50  	_, ok := recorder.(*record.FakeRecorder)
    51  	if ok {
    52  		return nil, nil
    53  	}
    54  
    55  	oomStreamer, err := oomparser.New()
    56  	if err != nil {
    57  		return nil, err
    58  	}
    59  
    60  	watcher := &realWatcher{
    61  		recorder:    recorder,
    62  		oomStreamer: oomStreamer,
    63  	}
    64  
    65  	return watcher, nil
    66  }
    67  
    68  const (
    69  	systemOOMEvent           = "SystemOOM"
    70  	recordEventContainerName = "/"
    71  )
    72  
    73  // Start watches for system oom's and records an event for every system oom encountered.
    74  func (ow *realWatcher) Start(ref *v1.ObjectReference) error {
    75  	outStream := make(chan *oomparser.OomInstance, 10)
    76  	go ow.oomStreamer.StreamOoms(outStream)
    77  
    78  	go func() {
    79  		defer runtime.HandleCrash()
    80  
    81  		for event := range outStream {
    82  			if event.VictimContainerName == recordEventContainerName {
    83  				klog.V(1).InfoS("Got sys oom event", "event", event)
    84  				eventMsg := "System OOM encountered"
    85  				if event.ProcessName != "" && event.Pid != 0 {
    86  					eventMsg = fmt.Sprintf("%s, victim process: %s, pid: %d", eventMsg, event.ProcessName, event.Pid)
    87  				}
    88  				ow.recorder.Eventf(ref, v1.EventTypeWarning, systemOOMEvent, eventMsg)
    89  			}
    90  		}
    91  		klog.ErrorS(nil, "Unexpectedly stopped receiving OOM notifications")
    92  	}()
    93  	return nil
    94  }
    95
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