summaryrefslogtreecommitdiff
path: root/libpod/logs/log.go
blob: 488291cfe6980132c5eb33fe249e9666f5e224b5 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
package logs

import (
	"fmt"
	"io/ioutil"
	"strings"
	"sync"
	"time"

	"github.com/hpcloud/tail"
	"github.com/pkg/errors"
)

const (
	// LogTimeFormat is the time format used in the log.
	// It is a modified version of RFC3339Nano that guarantees trailing
	// zeroes are not trimmed, taken from
	// https://github.com/golang/go/issues/19635
	LogTimeFormat = "2006-01-02T15:04:05.000000000Z07:00"

	// PartialLogType signifies a log line that exceeded the buffer
	// length and needed to spill into a new line
	PartialLogType = "P"

	// FullLogType signifies a log line is full
	FullLogType = "F"
)

// LogOptions is the options you can use for logs
type LogOptions struct {
	Details    bool
	Follow     bool
	Since      time.Time
	Tail       uint64
	Timestamps bool
	Multi      bool
	WaitGroup  *sync.WaitGroup
}

// LogLine describes the information for each line of a log
type LogLine struct {
	Device       string
	ParseLogType string
	Time         time.Time
	Msg          string
	CID          string
}

// GetLogFile returns an hp tail for a container given options
func GetLogFile(path string, options *LogOptions) (*tail.Tail, []*LogLine, error) {
	var (
		whence  int
		err     error
		logTail []*LogLine
	)
	// whence 0=origin, 2=end
	if options.Tail > 0 {
		whence = 2
		logTail, err = getTailLog(path, int(options.Tail))
		if err != nil {
			return nil, nil, err
		}
	}
	seek := tail.SeekInfo{
		Offset: 0,
		Whence: whence,
	}

	t, err := tail.TailFile(path, tail.Config{MustExist: true, Poll: true, Follow: options.Follow, Location: &seek, Logger: tail.DiscardingLogger})
	return t, logTail, err
}

func getTailLog(path string, tail int) ([]*LogLine, error) {
	var (
		tailLog     []*LogLine
		nlls        []*LogLine
		tailCounter int
		partial     string
	)
	content, err := ioutil.ReadFile(path)
	if err != nil {
		return nil, err
	}
	splitContent := strings.Split(string(content), "\n")
	// We read the content in reverse and add each nll until we have the same
	// number of F type messages as the desired tail
	for i := len(splitContent) - 1; i >= 0; i-- {
		if len(splitContent[i]) == 0 {
			continue
		}
		nll, err := NewLogLine(splitContent[i])
		if err != nil {
			return nil, err
		}
		nlls = append(nlls, nll)
		if !nll.Partial() {
			tailCounter = tailCounter + 1
		}
		if tailCounter == tail {
			break
		}
	}
	// Now we iterate the results and assemble partial messages to become full messages
	for _, nll := range nlls {
		if nll.Partial() {
			partial = partial + nll.Msg
		} else {
			nll.Msg = nll.Msg + partial
			tailLog = append(tailLog, nll)
			partial = ""
		}
	}
	return tailLog, nil
}

// String converts a logline to a string for output given whether a detail
// bool is specified.
func (l *LogLine) String(options *LogOptions) string {
	var out string
	if options.Multi {
		cid := l.CID
		if len(cid) > 12 {
			cid = cid[:12]
		}
		out = fmt.Sprintf("%s ", cid)
	}
	if options.Timestamps {
		out = out + fmt.Sprintf("%s ", l.Time.Format(LogTimeFormat))
	}
	return out + l.Msg
}

// Since returns a bool as to whether a log line occurred after a given time
func (l *LogLine) Since(since time.Time) bool {
	return l.Time.After(since)
}

// NewLogLine creates a logLine struct from a container log string
func NewLogLine(line string) (*LogLine, error) {
	splitLine := strings.Split(line, " ")
	if len(splitLine) < 4 {
		return nil, errors.Errorf("'%s' is not a valid container log line", line)
	}
	logTime, err := time.Parse(LogTimeFormat, splitLine[0])
	if err != nil {
		return nil, errors.Wrapf(err, "unable to convert time %s from container log", splitLine[0])
	}
	l := LogLine{
		Time:         logTime,
		Device:       splitLine[1],
		ParseLogType: splitLine[2],
		Msg:          strings.Join(splitLine[3:], " "),
	}
	return &l, nil
}

// Partial returns a bool if the log line is a partial log type
func (l *LogLine) Partial() bool {
	if l.ParseLogType == PartialLogType {
		return true
	}
	return false
}