podman/libpod/events/journal_linux.go

315 lines
9.3 KiB
Go

//go:build systemd
package events
import (
"context"
"encoding/json"
"errors"
"fmt"
"strconv"
"time"
"github.com/containers/podman/v5/pkg/rootless"
"github.com/containers/podman/v5/pkg/util"
"github.com/coreos/go-systemd/v22/journal"
"github.com/coreos/go-systemd/v22/sdjournal"
"github.com/sirupsen/logrus"
)
// EventJournalD is the journald implementation of an eventer
type EventJournalD struct {
options EventerOptions
}
// newJournalDEventer creates a new EventJournalD Eventer
func newJournalDEventer(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
if ee.Error != "" {
m["ERROR"] = ee.Error
}
case Container, Pod:
m["PODMAN_IMAGE"] = ee.Image
m["PODMAN_NAME"] = ee.Name
m["PODMAN_ID"] = ee.ID
if ee.ContainerExitCode != nil {
m["PODMAN_EXIT_CODE"] = strconv.Itoa(*ee.ContainerExitCode)
}
if ee.PodID != "" {
m["PODMAN_POD_ID"] = ee.PodID
}
// If we have container labels, we need to convert them to a string so they
// can be recorded with the event
if len(ee.Details.Attributes) > 0 {
b, err := json.Marshal(ee.Details.Attributes)
if err != nil {
return err
}
m["PODMAN_LABELS"] = string(b)
}
if ee.Status == HealthStatus {
m["PODMAN_HEALTH_STATUS"] = ee.HealthStatus
if ee.HealthLog != "" {
m["PODMAN_HEALTH_LOG"] = ee.HealthLog
}
m["PODMAN_HEALTH_FAILING_STREAK"] = strconv.Itoa(ee.HealthFailingStreak)
}
if len(ee.Details.ContainerInspectData) > 0 {
m["PODMAN_CONTAINER_INSPECT_DATA"] = ee.Details.ContainerInspectData
}
case Network:
m["PODMAN_ID"] = ee.ID
m["PODMAN_NETWORK_NAME"] = ee.Network
case Volume:
m["PODMAN_NAME"] = ee.Name
}
// starting with commit 7e6e267329 we set LogLevel=notice for the systemd healthcheck unit
// This so it doesn't log the started/stopped unit messages al the time which spam the
// journal if a small interval is used. That however broke the healthcheck event as it no
// longer showed up in podman events when running as root as we only send the event on info
// level. To fix this we have to send the event on notice level.
// https://github.com/containers/podman/issues/20342
prio := journal.PriInfo
if len(ee.HealthStatus) > 0 {
prio = journal.PriNotice
}
return journal.Send(ee.ToHumanReadable(false), prio, m)
}
// Read reads events from the journal and sends qualified events to the event channel
func (e EventJournalD) Read(ctx context.Context, options ReadOptions) (retErr error) {
filterMap, err := generateEventFilters(options.Filters, options.Since, options.Until)
if err != nil {
return fmt.Errorf("failed to parse event filters: %w", err)
}
var untilTime time.Time
if len(options.Until) > 0 {
untilTime, err = util.ParseInputTime(options.Until, false)
if err != nil {
return err
}
}
j, err := sdjournal.NewJournal()
if err != nil {
return err
}
defer func() {
if retErr != nil {
if err := j.Close(); err != nil {
logrus.Errorf("Unable to close journal :%v", err)
}
}
}()
err = j.SetDataThreshold(0)
if err != nil {
return fmt.Errorf("cannot set data threshold for journal: %v", err)
}
// match only podman journal entries
podmanJournal := sdjournal.Match{Field: "SYSLOG_IDENTIFIER", Value: "podman"}
if err := j.AddMatch(podmanJournal.String()); err != nil {
return fmt.Errorf("failed to add SYSLOG_IDENTIFIER journal filter for event log: %w", err)
}
// make sure we only read events for the current user
uidMatch := sdjournal.Match{Field: "_UID", Value: strconv.Itoa(rootless.GetRootlessUID())}
if err := j.AddMatch(uidMatch.String()); err != nil {
return fmt.Errorf("failed to add _UID journal filter for event log: %w", err)
}
if len(options.Since) == 0 && len(options.Until) == 0 && options.Stream {
if err := j.SeekTail(); err != nil {
return fmt.Errorf("failed to seek end of journal: %w", err)
}
// After SeekTail calling Next moves to a random entry.
// To prevent this we have to call Previous first.
// see: https://bugs.freedesktop.org/show_bug.cgi?id=64614
if _, err := j.Previous(); err != nil {
return fmt.Errorf("failed to move journal cursor to previous entry: %w", err)
}
} else if len(options.Since) > 0 {
since, err := util.ParseInputTime(options.Since, true)
if err != nil {
return err
}
// seek based on time which helps to reduce unnecessary event reads
if err := j.SeekRealtimeUsec(uint64(since.UnixMicro())); err != nil {
return err
}
}
go func() {
defer close(options.EventChannel)
defer func() {
if err := j.Close(); err != nil {
logrus.Errorf("Unable to close journal :%v", err)
}
}()
for {
entry, err := GetNextEntry(ctx, j, options.Stream, untilTime)
if err != nil {
options.EventChannel <- ReadResult{Error: err}
break
}
// no entry == we hit the end
if entry == nil {
break
}
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.Is(err, ErrEventTypeBlank) {
options.EventChannel <- ReadResult{Error: fmt.Errorf("unable to decode event: %v", err)}
}
continue
}
if applyFilters(newEvent, filterMap) {
options.EventChannel <- ReadResult{Event: newEvent}
}
}
}()
return nil
}
func newEventFromJournalEntry(entry *sdjournal.JournalEntry) (*Event, error) {
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"]
newEvent.PodID = entry.Fields["PODMAN_POD_ID"]
if code, ok := entry.Fields["PODMAN_EXIT_CODE"]; ok {
intCode, err := strconv.Atoi(code)
if err != nil {
logrus.Errorf("Parsing event exit code %s", code)
} else {
newEvent.ContainerExitCode = &intCode
}
}
// we need to check for the presence of labels recorded to a container event
if stringLabels, ok := entry.Fields["PODMAN_LABELS"]; ok && len(stringLabels) > 0 {
labels := make(map[string]string, 0)
if err := json.Unmarshal([]byte(stringLabels), &labels); err != nil {
return nil, err
}
// if we have labels, add them to the event
if len(labels) > 0 {
newEvent.Attributes = labels
}
}
newEvent.HealthStatus = entry.Fields["PODMAN_HEALTH_STATUS"]
if log, ok := entry.Fields["PODMAN_HEALTH_LOG"]; ok {
newEvent.HealthLog = log
}
if FailingStreak, ok := entry.Fields["PODMAN_HEALTH_FAILING_STREAK"]; ok {
FailingStreakInt, err := strconv.Atoi(FailingStreak)
if err == nil {
newEvent.HealthFailingStreak = FailingStreakInt
}
}
newEvent.Details.ContainerInspectData = entry.Fields["PODMAN_CONTAINER_INSPECT_DATA"]
case Network:
newEvent.ID = entry.Fields["PODMAN_ID"]
newEvent.Network = entry.Fields["PODMAN_NETWORK_NAME"]
case Image:
newEvent.ID = entry.Fields["PODMAN_ID"]
if val, ok := entry.Fields["ERROR"]; ok {
newEvent.Error = val
}
}
return &newEvent, nil
}
// String returns a string representation of the logger
func (e EventJournalD) String() string {
return Journald.String()
}
// GetNextEntry returns the next entry in the journal. If the end of the
// journal is reached and stream is not set or the current time is after
// the until time this function returns nil,nil.
func GetNextEntry(ctx context.Context, j *sdjournal.Journal, stream bool, untilTime time.Time) (*sdjournal.JournalEntry, error) {
for {
select {
case <-ctx.Done():
// the consumer has cancelled
return nil, nil
default:
// fallthrough
}
// the api requires a next|prev before reading the event
ret, err := j.Next()
if err != nil {
return nil, fmt.Errorf("failed to move journal cursor to next entry: %w", err)
}
// ret == 0 equals EOF, see sd_journal_next(3)
if ret == 0 {
if !stream || (!untilTime.IsZero() && time.Now().After(untilTime)) {
// we hit the end and should not keep streaming
return nil, nil
}
// keep waiting for the next entry
// j.Wait() is blocking, this would cause the goroutine to hang forever
// if no more journal entries are generated and thus if the client
// has closed the connection in the meantime to leak memory.
// Waiting only 5 seconds makes sure we can check if the client closed in the
// meantime at least every 5 seconds.
t := 5 * time.Second
if !untilTime.IsZero() {
until := time.Until(untilTime)
if until < t {
t = until
}
}
_ = j.Wait(t)
continue
}
entry, err := j.GetEntry()
if err != nil {
return nil, fmt.Errorf("failed to read journal entry: %w", err)
}
return entry, nil
}
}