summaryrefslogtreecommitdiff
path: root/libpod/container_log.go
diff options
context:
space:
mode:
Diffstat (limited to 'libpod/container_log.go')
-rw-r--r--libpod/container_log.go213
1 files changed, 213 insertions, 0 deletions
diff --git a/libpod/container_log.go b/libpod/container_log.go
new file mode 100644
index 000000000..e998ad316
--- /dev/null
+++ b/libpod/container_log.go
@@ -0,0 +1,213 @@
+package libpod
+
+import (
+ "fmt"
+ "io/ioutil"
+ "os"
+ "strings"
+ "sync"
+ "time"
+
+ "github.com/hpcloud/tail"
+ "github.com/pkg/errors"
+ "github.com/sirupsen/logrus"
+)
+
+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"
+)
+
+// 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
+}
+
+// Log is a runtime function that can read one or more container logs.
+func (r *Runtime) Log(containers []*Container, options *LogOptions, logChannel chan *LogLine) error {
+ for _, ctr := range containers {
+ if err := ctr.ReadLog(options, logChannel); err != nil {
+ return err
+ }
+ }
+ return nil
+}
+
+// ReadLog reads a containers log based on the input options and returns loglines over a channel
+func (c *Container) ReadLog(options *LogOptions, logChannel chan *LogLine) error {
+ t, tailLog, err := getLogFile(c.LogPath(), options)
+ if err != nil {
+ // If the log file does not exist, this is not fatal.
+ if os.IsNotExist(errors.Cause(err)) {
+ return nil
+ }
+ return errors.Wrapf(err, "unable to read log file %s for %s ", c.ID(), c.LogPath())
+ }
+ options.WaitGroup.Add(1)
+ if len(tailLog) > 0 {
+ for _, nll := range tailLog {
+ nll.CID = c.ID()
+ if nll.Since(options.Since) {
+ logChannel <- nll
+ }
+ }
+ }
+
+ go func() {
+ var partial string
+ for line := range t.Lines {
+ nll, err := newLogLine(line.Text)
+ if err != nil {
+ logrus.Error(err)
+ continue
+ }
+ if nll.Partial() {
+ partial = partial + nll.Msg
+ continue
+ } else if !nll.Partial() && len(partial) > 1 {
+ nll.Msg = partial
+ partial = ""
+ }
+ nll.CID = c.ID()
+ if nll.Since(options.Since) {
+ logChannel <- nll
+ }
+ }
+ options.WaitGroup.Done()
+ }()
+ return nil
+}
+
+// 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(time.RFC3339Nano, 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 == "P" {
+ return true
+ }
+ return false
+}