@@ -17,86 +17,88 @@ package syslog
1717
1818import (
1919 "fmt"
20- "io"
21- "os"
22- "strings"
20+ "regexp"
2321 "time"
2422
2523 kerntypes "k8s.io/node-problem-detector/pkg/kernelmonitor/types"
2624
27- "github.com/google/cadvisor/utils/tail "
25+ "github.com/golang/glog "
2826)
2927
28+ // translator translates log line into internal log type based on user defined
29+ // regular expression.
30+ type translator struct {
31+ timestampRegexp * regexp.Regexp
32+ messageRegexp * regexp.Regexp
33+ timestampFormat string
34+ }
35+
36+ const (
37+ // NOTE that we support submatch for both timestamp and message regular expressions. When
38+ // there are multiple matches returned by submatch, only **the last** is used.
39+ // timestampKey is the key of timestamp regular expression in the plugin configuration.
40+ timestampKey = "timestamp"
41+ // messageKey is the key of message regular expression in the plugin configuration.
42+ messageKey = "message"
43+ // timestampFormatKey is the key of timestamp format string in the plugin configuration.
44+ timestampFormatKey = "timestampFormat"
45+ )
46+
47+ func newTranslatorOrDie (pluginConfig map [string ]string ) * translator {
48+ if err := validatePluginConfig (pluginConfig ); err != nil {
49+ glog .Errorf ("Failed to validate plugin configuration %+v: %v" , pluginConfig , err )
50+ }
51+ return & translator {
52+ timestampRegexp : regexp .MustCompile (pluginConfig [timestampKey ]),
53+ messageRegexp : regexp .MustCompile (pluginConfig [messageKey ]),
54+ timestampFormat : pluginConfig [timestampFormatKey ],
55+ }
56+ }
57+
3058// translate translates the log line into internal type.
31- func translate (line string ) (* kerntypes.KernelLog , error ) {
32- timestamp , message , err := parseLine (line )
59+ func (t * translator ) translate (line string ) (* kerntypes.KernelLog , error ) {
60+ // Parse timestamp.
61+ matches := t .timestampRegexp .FindStringSubmatch (line )
62+ if len (matches ) == 0 {
63+ return nil , fmt .Errorf ("no timestamp found in line %q with regular expression %v" , line , t .timestampRegexp )
64+ }
65+ timestamp , err := time .ParseInLocation (t .timestampFormat , matches [len (matches )- 1 ], time .Local )
3366 if err != nil {
34- return nil , err
67+ return nil , fmt .Errorf ("failed to parse timestamp %q: %v" , matches [len (matches )- 1 ], err )
68+ }
69+ // Formalize the timestmap.
70+ timestamp = formalizeTimestamp (timestamp )
71+ // Parse message.
72+ matches = t .messageRegexp .FindStringSubmatch (line )
73+ if len (matches ) == 0 {
74+ return nil , fmt .Errorf ("no message found in line %q with regular expression %v" , line , t .messageRegexp )
3575 }
76+ message := matches [len (matches )- 1 ]
3677 return & kerntypes.KernelLog {
3778 Timestamp : timestamp ,
3879 Message : message ,
3980 }, nil
4081}
4182
42- const (
43- // timestampLen is the length of timestamp in syslog logging format.
44- timestampLen = 15
45- // messagePrefix is the character before real message.
46- messagePrefix = "]"
47- )
48-
49- // parseLine parses one log line into timestamp and message.
50- func parseLine (line string ) (time.Time , string , error ) {
51- // Trim the spaces to make sure timestamp could be found
52- line = strings .TrimSpace (line )
53- if len (line ) < timestampLen {
54- return time.Time {}, "" , fmt .Errorf ("the line is too short: %q" , line )
83+ // validatePluginConfig validates whether the plugin configuration.
84+ func validatePluginConfig (cfg map [string ]string ) error {
85+ if cfg [timestampKey ] == "" {
86+ return fmt .Errorf ("unexpected empty timestamp regular expression" )
5587 }
56- // Example line: Jan 1 00:00:00 hostname kernel: [0.000000] component: log message
57- now := time .Now ()
58- // There is no time zone information in kernel log timestamp, apply the current time
59- // zone.
60- timestamp , err := time .ParseInLocation (time .Stamp , line [:timestampLen ], time .Local )
61- if err != nil {
62- return time.Time {}, "" , fmt .Errorf ("error parsing timestamp in line %q: %v" , line , err )
88+ if cfg [messageKey ] == "" {
89+ return fmt .Errorf ("unexpected empty message regular expression" )
6390 }
64- // There is no year information in kernel log timestamp, apply the current year.
65- // This could go wrong during looking back phase after kernel monitor is started,
66- // and the old logs are generated in old year.
67- timestamp = timestamp .AddDate (now .Year (), 0 , 0 )
68-
69- loc := strings .Index (line , messagePrefix )
70- if loc == - 1 {
71- return timestamp , "" , fmt .Errorf ("can't find message prefix %q in line %q" , messagePrefix , line )
91+ if cfg [timestampFormatKey ] == "" {
92+ return fmt .Errorf ("unexpected empty timestamp format string" )
7293 }
73- message := strings .Trim (line [loc + 1 :], " " )
74-
75- return timestamp , message , nil
94+ return nil
7695}
7796
78- // defaultKernelLogPath the default path of syslog kernel log.
79- const defaultKernelLogPath = "/var/log/kern.log"
80-
81- // getLogReader returns log reader for syslog log. Note that getLogReader doesn't look back
82- // to the rolled out logs.
83- func getLogReader (path string ) (io.ReadCloser , error ) {
84- if path == "" {
85- path = defaultKernelLogPath
86- }
87- // To handle log rotation, tail will not report error immediately if
88- // the file doesn't exist. So we check file existence frist.
89- // This could go wrong during mid-rotation. It should recover after
90- // several restart when the log file is created again. The chance
91- // is slim but we should still fix this in the future.
92- // TODO(random-liu): Handle log missing during rotation.
93- _ , err := os .Stat (path )
94- if err != nil {
95- return nil , fmt .Errorf ("failed to stat the file %q: %v" , path , err )
96- }
97- tail , err := tail .NewTail (path )
98- if err != nil {
99- return nil , fmt .Errorf ("failed to tail the file %q: %v" , path , err )
97+ // formalizeTimestamp formalizes the timestamp. We need this because some log doesn't contain full
98+ // timestamp, e.g. syslog.
99+ func formalizeTimestamp (t time.Time ) time.Time {
100+ if t .Year () == 0 {
101+ t = t .AddDate (time .Now ().Year (), 0 , 0 )
100102 }
101- return tail , nil
103+ return t
102104}
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