add skiplist filter example in filelog config and add test case

Author: smileusd

config/docker-monitor-filelog.json

@@ -9,6 +9,7 @@
 	"lookback": "5m",
 	"bufferSize": 10,
 	"source": "docker-monitor",
+	"skipList": [],
 	"conditions": [],
 	"rules": [
 		{

config/kernel-monitor-filelog.json

@@ -9,6 +9,7 @@
 	"lookback": "5m",
 	"bufferSize": 10,
 	"source": "kernel-monitor",
+	"skipList": [ " audit:", " audit[" ],
 	"conditions": [
 		{
 			"type": "KernelDeadlock",

pkg/systemlogmonitor/logwatchers/filelog/log_watcher_test.go

@@ -176,3 +176,36 @@ Jan  2 03:04:05 kernel: [2.000000] 3
 		}
 	}
 }
+
+func TestFilterSkipList(t *testing.T) {
+	s := &filelogWatcher{
+		cfg: types.WatcherConfig{
+			SkipList: []string{
+				" audit:", " kubelet:",
+			},
+		},
+	}
+	testcase := []struct{
+		log string
+		expect bool
+	}{
+		{
+			log: `Jan  2 03:04:03 kernel: [0.000000] 1`,
+			expect: false,
+		},
+		{
+			log: `Jan  2 03:04:04 audit: [1.000000] 2`,
+			expect: true,
+		},
+		{
+			log: `Jan  2 03:04:05 kubelet: [2.000000] 3`,
+			expect: true,
+
+		},
+	}
+	for i, test := range testcase {
+		if s.filterSkipList(test.log) != test.expect {
+			t.Errorf("test case %d: expect %v but got %v", i, test.expect, s.filterSkipList(test.log))
+		}
+	}
+}