aboutsummaryrefslogtreecommitdiff
path: root/libpod/events/journal_linux.go
blob: 470c76959c7dd78c5f288c598e8552570a6882df (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
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
// +build systemd

package events

import (
	"fmt"
	"strconv"
	"time"

	"github.com/coreos/go-systemd/journal"
	"github.com/coreos/go-systemd/sdjournal"
	"github.com/pkg/errors"
	"github.com/sirupsen/logrus"
)

// DefaultEventerType is journald when systemd is available
const DefaultEventerType = Journald

// EventJournalD is the journald implementation of an eventer
type EventJournalD struct {
	options EventerOptions
}

// newEventJournalD creates a new journald Eventer
func newEventJournalD(options EventerOptions) (Eventer, error) {
	return EventJournalD{options}, nil
}

// Write to journald
func (e EventJournalD) Write(ee Event) error {
	m := make(map[string]string)
	m["SYSLOG_IDENTIFIER"] = "podman"
	m["PODMAN_EVENT"] = ee.Status.String()
	m["PODMAN_TYPE"] = ee.Type.String()
	m["PODMAN_TIME"] = ee.Time.Format(time.RFC3339Nano)

	// Add specialized information based on the podman type
	switch ee.Type {
	case Image:
		m["PODMAN_NAME"] = ee.Name
		m["PODMAN_ID"] = ee.ID
	case Container, Pod:
		m["PODMAN_IMAGE"] = ee.Image
		m["PODMAN_NAME"] = ee.Name
		m["PODMAN_ID"] = ee.ID
		if ee.ContainerExitCode != 0 {
			m["PODMAN_EXIT_CODE"] = strconv.Itoa(ee.ContainerExitCode)
		}
	case Volume:
		m["PODMAN_NAME"] = ee.Name
	}
	return journal.Send(fmt.Sprintf("%s", ee.ToHumanReadable()), journal.PriInfo, m)
}

// Read reads events from the journal and sends qualified events to the event channel
func (e EventJournalD) Read(options ReadOptions) error {
	eventOptions, err := generateEventOptions(options.Filters, options.Since, options.Until)
	if err != nil {
		return errors.Wrapf(err, "failed to generate event options")
	}
	j, err := sdjournal.NewJournal() //nolint
	if err != nil {
		return err
	}
	// TODO AddMatch and Seek seem to conflict
	// Issue filed upstream -> https://github.com/coreos/go-systemd/issues/315
	// Leaving commented code in case upstream fixes things
	//podmanJournal := sdjournal.Match{Field: "SYSLOG_IDENTIFIER", Value: "podman"} //nolint
	//if err := j.AddMatch(podmanJournal.String()); err != nil {
	//	return errors.Wrap(err, "failed to add filter for event log")
	//}
	if len(options.Since) == 0 && len(options.Until) == 0 && options.Stream {
		if err := j.SeekTail(); err != nil {
			return errors.Wrap(err, "failed to seek end of journal")
		}
	} else {
		podmanJournal := sdjournal.Match{Field: "SYSLOG_IDENTIFIER", Value: "podman"} //nolint
		if err := j.AddMatch(podmanJournal.String()); err != nil {
			return errors.Wrap(err, "failed to add filter for event log")
		}
	}
	// the api requires a next|prev before getting a cursor
	if _, err := j.Next(); err != nil {
		return err
	}
	prevCursor, err := j.GetCursor()
	if err != nil {
		return err
	}
	defer close(options.EventChannel)
	for {
		if _, err := j.Next(); err != nil {
			return err
		}
		newCursor, err := j.GetCursor()
		if err != nil {
			return err
		}
		if prevCursor == newCursor {
			if len(options.Until) > 0 || !options.Stream {
				break
			}
			_ = j.Wait(sdjournal.IndefiniteWait) //nolint
			continue
		}
		prevCursor = newCursor
		entry, err := j.GetEntry()
		if err != nil {
			return err
		}
		// TODO this keeps us from feeding the podman event parser with
		// with regular journal content; it can be removed if the above
		// problem with AddMatch is resolved.
		if entry.Fields["PODMAN_EVENT"] == "" {
			continue
		}
		newEvent, err := newEventFromJournalEntry(entry)
		if err != nil {
			// We can't decode this event.
			// Don't fail hard - that would make events unusable.
			// Instead, log and continue.
			if errors.Cause(err) != ErrEventTypeBlank {
				logrus.Errorf("Unable to decode event: %v", err)
			}
			continue
		}
		include := true
		for _, filter := range eventOptions {
			include = include && filter(newEvent)
		}
		if include {
			options.EventChannel <- newEvent
		}
	}
	return nil

}

func newEventFromJournalEntry(entry *sdjournal.JournalEntry) (*Event, error) { //nolint
	newEvent := Event{}
	eventType, err := StringToType(entry.Fields["PODMAN_TYPE"])
	if err != nil {
		return nil, err
	}
	eventTime, err := time.Parse(time.RFC3339Nano, entry.Fields["PODMAN_TIME"])
	if err != nil {
		return nil, err
	}
	eventStatus, err := StringToStatus(entry.Fields["PODMAN_EVENT"])
	if err != nil {
		return nil, err
	}
	newEvent.Type = eventType
	newEvent.Time = eventTime
	newEvent.Status = eventStatus
	newEvent.Name = entry.Fields["PODMAN_NAME"]

	switch eventType {
	case Container, Pod:
		newEvent.ID = entry.Fields["PODMAN_ID"]
		newEvent.Image = entry.Fields["PODMAN_IMAGE"]
		if code, ok := entry.Fields["PODMAN_EXIT_CODE"]; ok {
			intCode, err := strconv.Atoi(code)
			if err != nil {
				logrus.Errorf("Error parsing event exit code %s", code)
			} else {
				newEvent.ContainerExitCode = intCode
			}
		}
	case Image:
		newEvent.ID = entry.Fields["PODMAN_ID"]
	}
	return &newEvent, nil
}

// String returns a string representation of the logger
func (e EventJournalD) String() string {
	return Journald.String()
}