From 02f971131a3bb71615d15a45df808edd0fa88266 Mon Sep 17 00:00:00 2001 From: Peter Hunt Date: Sat, 18 May 2019 22:17:37 -0400 Subject: Implement podman logs with log-driver journald Add a journald reader that translates the journald entry to a k8s-file formatted line, to be added as a log line Note: --follow with journald hasn't been implemented. It's going to be a larger undertaking that can wait. Signed-off-by: Peter Hunt --- libpod/container_log.go | 25 ++++++-- libpod/container_log_linux.go | 114 ++++++++++++++++++++++++++++++++++++ libpod/container_log_unsupported.go | 7 +++ libpod/oci.go | 6 ++ libpod/oci_linux.go | 2 +- 5 files changed, 149 insertions(+), 5 deletions(-) create mode 100644 libpod/container_log_linux.go create mode 100644 libpod/container_log_unsupported.go (limited to 'libpod') diff --git a/libpod/container_log.go b/libpod/container_log.go index f11db8014..9276b52f4 100644 --- a/libpod/container_log.go +++ b/libpod/container_log.go @@ -19,6 +19,16 @@ const ( // zeroes are not trimmed, taken from // https://github.com/golang/go/issues/19635 logTimeFormat = "2006-01-02T15:04:05.000000000Z07:00" + + // readLogTimeFormat is the format the log lines will be read in + readLogTimeFormat = time.RFC3339Nano + + // 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 @@ -55,9 +65,16 @@ func (r *Runtime) Log(containers []*Container, options *LogOptions, logChannel c func (c *Container) ReadLog(options *LogOptions, logChannel chan *LogLine) error { // TODO Skip sending logs until journald logs can be read // TODO make this not a magic string - if c.LogDriver() == "journald" { - return ErrNotImplemented + if c.LogDriver() == JournaldLogging { + if options.Follow { + return errors.Errorf("The follow option with journald logging is not currently supported") + } + return c.readFromJournal(options, logChannel) } + return c.readFromLogFile(options, logChannel) +} + +func (c *Container) readFromLogFile(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. @@ -196,7 +213,7 @@ func newLogLine(line string) (*LogLine, error) { 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]) + logTime, err := time.Parse(readLogTimeFormat, splitLine[0]) if err != nil { return nil, errors.Wrapf(err, "unable to convert time %s from container log", splitLine[0]) } @@ -211,7 +228,7 @@ func newLogLine(line string) (*LogLine, error) { // Partial returns a bool if the log line is a partial log type func (l *LogLine) Partial() bool { - if l.ParseLogType == "P" { + if l.ParseLogType == partialLogType { return true } return false diff --git a/libpod/container_log_linux.go b/libpod/container_log_linux.go new file mode 100644 index 000000000..47dc44b8f --- /dev/null +++ b/libpod/container_log_linux.go @@ -0,0 +1,114 @@ +//+build linux + +package libpod + +import ( + "fmt" + "io" + "strings" + "time" + + journal "github.com/coreos/go-systemd/sdjournal" + "github.com/pkg/errors" + "github.com/sirupsen/logrus" +) + +const ( + // journaldLogOut is the journald priority signifying stdout + journaldLogOut = "6" + + // journaldLogErr is the journald priority signifying stderr + journaldLogErr = "3" + + // bufLen is the length of the buffer to read from a k8s-file + // formatted log line + // It consists of conmon.TSBUFLEN+2+conmon.STDIOBUFSIZE+'\0' + bufLen = 44 + 2 + 8192 + 1 +) + +func (c *Container) readFromJournal(options *LogOptions, logChannel chan *LogLine) error { + var config journal.JournalReaderConfig + config.NumFromTail = options.Tail + config.Formatter = journalFormatter + defaultTime := time.Time{} + if options.Since != defaultTime { + // coreos/go-systemd/sdjournal doesn't correctly handle requests for data in the future + // return nothing instead of fasely printing + if time.Now().Before(options.Since) { + return nil + } + config.Since = time.Since(options.Since) + } + config.Matches = append(config.Matches, journal.Match{ + Field: "CONTAINER_ID_FULL", + Value: c.ID(), + }) + options.WaitGroup.Add(1) + + r, err := journal.NewJournalReader(config) + if err != nil { + return err + } + if r == nil { + return errors.Errorf("journal reader creation failed") + } + if options.Tail == 0 { + r.Rewind() + } + + go func() { + bytes := make([]byte, bufLen) + // /me complains about no do-while in go + ec, err := r.Read(bytes) + for ec != 0 && err == nil { + // because we are reusing bytes, we need to make + // sure the old data doesn't get into the new line + bytestr := string(bytes[:ec]) + logLine, err2 := newLogLine(bytestr) + if err2 != nil { + logrus.Error(err2) + continue + } + logChannel <- logLine + ec, err = r.Read(bytes) + } + if err != nil && err != io.EOF { + logrus.Error(err) + } + r.Close() + options.WaitGroup.Done() + }() + return nil +} + +func journalFormatter(entry *journal.JournalEntry) (string, error) { + usec := entry.RealtimeTimestamp + timestamp := time.Unix(0, int64(usec)*int64(time.Microsecond)) + output := timestamp.Format(readLogTimeFormat) + " " + priority, ok := entry.Fields["PRIORITY"] + if !ok { + return "", errors.Errorf("no PRIORITY field present in journal entry") + } + if priority == journaldLogOut { + output += "stdout " + } else if priority == journaldLogErr { + output += "stderr " + } else { + return "", errors.Errorf("unexpected PRIORITY field in journal entry") + } + + // if CONTAINER_PARTIAL_MESSAGE is defined, the log type is "P" + if _, ok := entry.Fields["CONTAINER_PARTIAL_MESSAGE"]; ok { + output += fmt.Sprintf("%s ", partialLogType) + } else { + output += fmt.Sprintf("%s ", fullLogType) + } + + // Finally, append the message + msg, ok := entry.Fields["MESSAGE"] + if !ok { + return "", fmt.Errorf("no MESSAGE field present in journal entry") + } + output += strings.TrimSpace(msg) + return output, nil +} diff --git a/libpod/container_log_unsupported.go b/libpod/container_log_unsupported.go new file mode 100644 index 000000000..0c3d41620 --- /dev/null +++ b/libpod/container_log_unsupported.go @@ -0,0 +1,7 @@ +//+build !linux + +package libpod + +func (c *Container) readFromJournal(options *LogOptions, logChannel chan *LogLine) error { + return ErrOSNotSupported +} diff --git a/libpod/oci.go b/libpod/oci.go index 152c8e73e..a3e44bcce 100644 --- a/libpod/oci.go +++ b/libpod/oci.go @@ -42,6 +42,12 @@ const ( // NsRunDir is the default directory in which running network namespaces // are stored NsRunDir = "/var/run/netns" + + // JournaldLogging is the string conmon expects to specify journald logging + JournaldLogging = "journald" + + // KubernetesLogging is the string conmon expects when specifying to use the kubernetes logging format + KubernetesLogging = "k8s-file" ) // OCIRuntime represents an OCI-compatible runtime that libpod can call into diff --git a/libpod/oci_linux.go b/libpod/oci_linux.go index b3a21948e..5d66e6d82 100644 --- a/libpod/oci_linux.go +++ b/libpod/oci_linux.go @@ -237,7 +237,7 @@ func (r *OCIRuntime) createOCIContainer(ctr *Container, cgroupParent string, res args = append(args, "--log-size-max", fmt.Sprintf("%v", r.logSizeMax)) } - logDriver := "k8s-file" + logDriver := KubernetesLogging if ctr.LogDriver() != "" { logDriver = ctr.LogDriver() } -- cgit v1.2.3-54-g00ecf