add log-counter go plugin

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)
+}