add log-counter go plugin

Makefile

@@ -77,6 +77,11 @@ fmt:
 version:
 	@echo $(VERSION)
 
+./bin/log-counter: $(PKG_SOURCES)
+	CGO_ENABLED=$(CGO_ENABLED) GOOS=linux go build -o bin/log-counter \
+	     -ldflags '-X $(PKG)/pkg/version.version=$(VERSION)' \
+	     $(BUILD_TAGS) cmd/logcounter/log_counter.go
+
 ./bin/node-problem-detector: $(PKG_SOURCES)
 	CGO_ENABLED=$(CGO_ENABLED) GOOS=linux go build -o bin/node-problem-detector \
 	     -ldflags '-X $(PKG)/pkg/version.version=$(VERSION)' \
@@ -88,10 +93,10 @@ Dockerfile: Dockerfile.in
 test: vet fmt
 	go test -timeout=1m -v -race ./cmd/options ./pkg/... $(BUILD_TAGS)
 
-build-container: ./bin/node-problem-detector Dockerfile
+build-container: ./bin/node-problem-detector ./bin/log-counter Dockerfile
 	docker build -t $(IMAGE) .
 
-build-tar: ./bin/node-problem-detector
+build-tar: ./bin/node-problem-detector ./bin/log-counter
 	tar -zcvf $(TARBALL) bin/ config/
 	sha1sum $(TARBALL)
 	md5sum $(TARBALL)
@@ -107,5 +112,6 @@ push-tar: build-tar
 push: push-container push-tar
 
 clean:
+	rm -f bin/log-counter
 	rm -f bin/node-problem-detector
 	rm -f node-problem-detector-*.tar.gz

cmd/logcounter/log_counter.go

@@ -0,0 +1,46 @@
+/*
+Copyright 2018 The Kubernetes Authors 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 main
+
+import (
+	"fmt"
+	"os"
+
+	"github.com/spf13/pflag"
+
+	"k8s.io/node-problem-detector/cmd/logcounter/options"
+	"k8s.io/node-problem-detector/pkg/custompluginmonitor/types"
+	"k8s.io/node-problem-detector/pkg/logcounter"
+)
+
+func main() {
+	fedo := options.NewLogCounterOptions()
+	fedo.AddFlags(pflag.CommandLine)
+	pflag.Parse()
+
+	counter, err := logcounter.NewKmsgLogCounter(fedo)
+	if err != nil {
+		fmt.Print(err)
+		os.Exit(int(types.Unknown))
+	}
+	actual := counter.Count()
+	if actual >= fedo.Count {
+		fmt.Printf("Found %d matching logs, which meets the threshold of %d\n", actual, fedo.Count)
+		os.Exit(int(types.NonOK))
+	}
+	os.Exit(int(types.OK))
+}

cmd/logcounter/options/options.go

@@ -0,0 +1,48 @@
+/*
+Copyright 2018 The Kubernetes Authors 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 options
+
+import (
+	"flag"
+
+	"github.com/spf13/pflag"
+)
+
+func NewLogCounterOptions() *LogCounterOptions {
+	return &LogCounterOptions{}
+}
+
+// LogCounterOptions contains frequent event detector command line and application options.
+type LogCounterOptions struct {
+	// command line options. See flag descriptions for the description
+	Lookback string
+	Pattern  string
+	Count    int
+}
+
+// AddFlags adds log counter command line options to pflag.
+func (fedo *LogCounterOptions) AddFlags(fs *pflag.FlagSet) {
+	fs.StringVar(&fedo.Lookback, "lookback", "", "The time log watcher looks up")
+	fs.StringVar(&fedo.Pattern, "pattern", "",
+		"The regular expression to match the problem in log. The pattern must match to the end of the line.")
+	fs.IntVar(&fedo.Count, "count", 1,
+		"The number of times the pattern must be found to trigger the condition")
+}
+
+func init() {
+	pflag.CommandLine.AddGoFlagSet(flag.CommandLine)
+}

config/kernel-monitor-counter.json

@@ -0,0 +1,31 @@
+{
+  "plugin": "custom",
+  "pluginConfig": {
+    "invoke_interval": "5m",
+    "timeout": "1m",
+    "max_output_length": 80,
+    "concurrency": 1
+  },
+  "source": "kernel-monitor",
+  "conditions": [
+    {
+      "type": "FrequentUnregisterNetDevice",
+      "reason": "NoFrequentUnregisterNetDevice",
+      "message": "node is functioning properly"
+    }
+  ],
+  "rules": [
+    {
+      "type": "permanent",
+      "condition": "FrequentUnregisterNetDevice",
+      "reason": "UnregisterNetDevice",
+      "path": "/home/kubernetes/bin/log-counter",
+      "args": [
+        "--lookback=20m",
+        "--count=3",
+        "--pattern=unregister_netdevice: waiting for \\w+ to become free. Usage count = \\d+"
+      ],
+      "timeout": "1m"
+    }
+  ]
+}

pkg/custompluginmonitor/plugin/plugin.go

@@ -108,7 +108,7 @@ func (p *Plugin) run(rule cpmtypes.CustomRule) (exitStatus cpmtypes.Status, outp
 	}
 	defer cancel()
 
-	cmd := exec.CommandContext(ctx, rule.Path)
+	cmd := exec.CommandContext(ctx, rule.Path, rule.Args...)
 	stdout, err := cmd.Output()
 	if err != nil {
 		if _, ok := err.(*exec.ExitError); !ok {

pkg/custompluginmonitor/types/types.go

@@ -48,6 +48,8 @@ type CustomRule struct {
 	Reason string `json:"reason"`
 	// Path is the path to the custom plugin.
 	Path string `json:"path"`
+	// Args is the args passed to the custom plugin.
+	Args []string `json:"args"`
 	// Timeout is the timeout string for the custom plugin to execute.
 	TimeoutString *string `json:"timeout"`
 	// Timeout is the timeout for the custom plugin to execute.

pkg/logcounter/log_counter.go

@@ -0,0 +1,78 @@
+/*
+Copyright 2018 The Kubernetes Authors 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 logcounter
+
+import (
+	"fmt"
+	"time"
+
+	"k8s.io/kubernetes/pkg/util/clock"
+
+	"k8s.io/node-problem-detector/cmd/logcounter/options"
+	"k8s.io/node-problem-detector/pkg/logcounter/types"
+	"k8s.io/node-problem-detector/pkg/systemlogmonitor"
+	"k8s.io/node-problem-detector/pkg/systemlogmonitor/logwatchers/kmsg"
+	watchertypes "k8s.io/node-problem-detector/pkg/systemlogmonitor/logwatchers/types"
+	systemtypes "k8s.io/node-problem-detector/pkg/systemlogmonitor/types"
+)
+
+const (
+	bufferSize = 1000
+	timeout    = 1 * time.Second
+)
+
+type logCounter struct {
+	logCh   <-chan *systemtypes.Log
+	buffer  systemlogmonitor.LogBuffer
+	pattern string
+	clock   clock.Clock
+}
+
+func NewKmsgLogCounter(options *options.LogCounterOptions) (types.LogCounter, error) {
+	watcher := kmsg.NewKmsgWatcher(watchertypes.WatcherConfig{Lookback: options.Lookback})
+	logCh, err := watcher.Watch()
+	if err != nil {
+		return nil, fmt.Errorf("error watching kmsg: %v", err)
+	}
+	return &logCounter{
+		logCh:   logCh,
+		buffer:  systemlogmonitor.NewLogBuffer(bufferSize),
+		pattern: options.Pattern,
+		clock:   clock.RealClock{},
+	}, nil
+}
+
+func (e *logCounter) Count() (count int) {
+	start := e.clock.Now()
+	for {
+		select {
+		case log := <-e.logCh:
+			// We only want to count events up until the time at which we started.
+			// Otherwise we would run forever
+			if start.Before(log.Timestamp) {
+				return
+			}
+			e.buffer.Push(log)
+			if len(e.buffer.Match(e.pattern)) != 0 {
+				count++
+			}
+		case <-e.clock.After(timeout):
+			// Don't block forever if we do not get any new messages
+			return
+		}
+	}
+}

pkg/logcounter/log_counter_test.go

@@ -0,0 +1,129 @@
+/*
+Copyright 2018 The Kubernetes Authors 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 logcounter
+
+import (
+	"testing"
+	"time"
+
+	"k8s.io/kubernetes/pkg/util/clock"
+
+	"k8s.io/node-problem-detector/pkg/logcounter/types"
+	"k8s.io/node-problem-detector/pkg/systemlogmonitor"
+	systemtypes "k8s.io/node-problem-detector/pkg/systemlogmonitor/types"
+)
+
+func NewTestLogCounter(pattern string, startTime time.Time) (types.LogCounter, *clock.FakeClock, chan *systemtypes.Log) {
+	logCh := make(chan *systemtypes.Log)
+	clock := clock.NewFakeClock(startTime)
+	return &logCounter{
+		logCh:   logCh,
+		buffer:  systemlogmonitor.NewLogBuffer(bufferSize),
+		pattern: pattern,
+		clock:   clock,
+	}, clock, logCh
+}
+
+func TestCount(t *testing.T) {
+	startTime := time.Now()
+	for _, tc := range []struct {
+		description   string
+		logs          []*systemtypes.Log
+		pattern       string
+		expectedCount int
+	}{
+		{
+			description:   "no logs",
+			logs:          []*systemtypes.Log{},
+			pattern:       "",
+			expectedCount: 0,
+		},
+		{
+			description: "one matching log",
+			logs: []*systemtypes.Log{
+				{
+					Timestamp: startTime.Add(-time.Second),
+					Message:   "0",
+				},
+			},
+			pattern:       "0",
+			expectedCount: 1,
+		},
+		{
+			description: "one non-matching log",
+			logs: []*systemtypes.Log{
+				{
+					Timestamp: startTime.Add(-time.Second),
+					Message:   "1",
+				},
+			},
+			pattern:       "0",
+			expectedCount: 0,
+		},
+		{
+			description: "log too new",
+			logs: []*systemtypes.Log{
+				{
+					Timestamp: startTime.Add(time.Second),
+					Message:   "0",
+				},
+			},
+			pattern:       "0",
+			expectedCount: 0,
+		},
+		{
+			description: "many logs",
+			logs: []*systemtypes.Log{
+				{
+					Timestamp: startTime.Add(-time.Second),
+					Message:   "0",
+				},
+				{
+					Timestamp: startTime.Add(-time.Second),
+					Message:   "0",
+				},
+				{
+					Timestamp: startTime.Add(-time.Second),
+					Message:   "1",
+				},
+				{
+					Timestamp: startTime.Add(time.Second),
+					Message:   "0",
+				},
+			},
+			pattern:       "0",
+			expectedCount: 2,
+		},
+	} {
+		t.Run(tc.description, func(t *testing.T) {
+			counter, fakeClock, logCh := NewTestLogCounter(tc.pattern, startTime)
+			go func(logs []*systemtypes.Log, ch chan<- *systemtypes.Log) {
+				for _, log := range logs {
+					ch <- log
+				}
+				// trigger the timeout to ensure the test doesn't block permenantly
+				for {
+					fakeClock.Step(2 * timeout)
+				}
+			}(tc.logs, logCh)
+			actualCount := counter.Count()
+			if actualCount != tc.expectedCount {
+				t.Errorf("got %d; expected %d", actualCount, tc.expectedCount)
+			}
+		})
+	}
+}