示例#1
0
//SeekHead seeks to the beginning of the journal, i.e. the oldest available entry.
func (j *Journal) SeekHead() error {
	j.mu.Lock()
	r := C.sd_journal_seek_head(j.cjournal)
	j.mu.Unlock()

	if r < 0 {
		return fmt.Errorf("failed to seek to head of journal: %d", r)
	}

	return nil
}
示例#2
0
文件: read.go 项目: DaveDaCoda/docker
func (s *journald) readLogs(logWatcher *logger.LogWatcher, config logger.ReadConfig) {
	var j *C.sd_journal
	var cmatch *C.char
	var stamp C.uint64_t
	var sinceUnixMicro uint64
	var pipes [2]C.int
	cursor := ""

	defer close(logWatcher.Msg)
	// Get a handle to the journal.
	rc := C.sd_journal_open(&j, C.int(0))
	if rc != 0 {
		logWatcher.Err <- fmt.Errorf("error opening journal")
		return
	}
	defer C.sd_journal_close(j)
	// Remove limits on the size of data items that we'll retrieve.
	rc = C.sd_journal_set_data_threshold(j, C.size_t(0))
	if rc != 0 {
		logWatcher.Err <- fmt.Errorf("error setting journal data threshold")
		return
	}
	// Add a match to have the library do the searching for us.
	cmatch = C.CString("CONTAINER_ID_FULL=" + s.vars["CONTAINER_ID_FULL"])
	defer C.free(unsafe.Pointer(cmatch))
	rc = C.sd_journal_add_match(j, unsafe.Pointer(cmatch), C.strlen(cmatch))
	if rc != 0 {
		logWatcher.Err <- fmt.Errorf("error setting journal match")
		return
	}
	// If we have a cutoff time, convert it to Unix time once.
	if !config.Since.IsZero() {
		nano := config.Since.UnixNano()
		sinceUnixMicro = uint64(nano / 1000)
	}
	if config.Tail > 0 {
		lines := config.Tail
		// Start at the end of the journal.
		if C.sd_journal_seek_tail(j) < 0 {
			logWatcher.Err <- fmt.Errorf("error seeking to end of journal")
			return
		}
		if C.sd_journal_previous(j) < 0 {
			logWatcher.Err <- fmt.Errorf("error backtracking to previous journal entry")
			return
		}
		// Walk backward.
		for lines > 0 {
			// Stop if the entry time is before our cutoff.
			// We'll need the entry time if it isn't, so go
			// ahead and parse it now.
			if C.sd_journal_get_realtime_usec(j, &stamp) != 0 {
				break
			} else {
				// Compare the timestamp on the entry
				// to our threshold value.
				if sinceUnixMicro != 0 && sinceUnixMicro > uint64(stamp) {
					break
				}
			}
			lines--
			// If we're at the start of the journal, or
			// don't need to back up past any more entries,
			// stop.
			if lines == 0 || C.sd_journal_previous(j) <= 0 {
				break
			}
		}
	} else {
		// Start at the beginning of the journal.
		if C.sd_journal_seek_head(j) < 0 {
			logWatcher.Err <- fmt.Errorf("error seeking to start of journal")
			return
		}
		// If we have a cutoff date, fast-forward to it.
		if sinceUnixMicro != 0 && C.sd_journal_seek_realtime_usec(j, C.uint64_t(sinceUnixMicro)) != 0 {
			logWatcher.Err <- fmt.Errorf("error seeking to start time in journal")
			return
		}
		if C.sd_journal_next(j) < 0 {
			logWatcher.Err <- fmt.Errorf("error skipping to next journal entry")
			return
		}
	}
	cursor = s.drainJournal(logWatcher, config, j, "")
	if config.Follow {
		// Create a pipe that we can poll at the same time as the journald descriptor.
		if C.pipe(&pipes[0]) == C.int(-1) {
			logWatcher.Err <- fmt.Errorf("error opening journald close notification pipe")
		} else {
			s.followJournal(logWatcher, config, j, pipes, cursor)
		}
	}
	return
}
示例#3
0
func (s *journald) readLogs(logWatcher *logger.LogWatcher, config logger.ReadConfig) {
	var j *C.sd_journal
	var cmatch *C.char
	var stamp C.uint64_t
	var sinceUnixMicro uint64
	var pipes [2]C.int
	cursor := ""

	// Get a handle to the journal.
	rc := C.sd_journal_open(&j, C.int(0))
	if rc != 0 {
		logWatcher.Err <- fmt.Errorf("error opening journal")
		close(logWatcher.Msg)
		return
	}
	// If we end up following the log, we can set the journal context
	// pointer and the channel pointer to nil so that we won't close them
	// here, potentially while the goroutine that uses them is still
	// running.  Otherwise, close them when we return from this function.
	following := false
	defer func(pfollowing *bool) {
		if !*pfollowing {
			C.sd_journal_close(j)
			close(logWatcher.Msg)
		}
	}(&following)
	// Remove limits on the size of data items that we'll retrieve.
	rc = C.sd_journal_set_data_threshold(j, C.size_t(0))
	if rc != 0 {
		logWatcher.Err <- fmt.Errorf("error setting journal data threshold")
		return
	}
	// Add a match to have the library do the searching for us.
	cmatch = C.CString("CONTAINER_ID_FULL=" + s.vars["CONTAINER_ID_FULL"])
	defer C.free(unsafe.Pointer(cmatch))
	rc = C.sd_journal_add_match(j, unsafe.Pointer(cmatch), C.strlen(cmatch))
	if rc != 0 {
		logWatcher.Err <- fmt.Errorf("error setting journal match")
		return
	}
	// If we have a cutoff time, convert it to Unix time once.
	if !config.Since.IsZero() {
		nano := config.Since.UnixNano()
		sinceUnixMicro = uint64(nano / 1000)
	}
	if config.Tail > 0 {
		lines := config.Tail
		// Start at the end of the journal.
		if C.sd_journal_seek_tail(j) < 0 {
			logWatcher.Err <- fmt.Errorf("error seeking to end of journal")
			return
		}
		if C.sd_journal_previous(j) < 0 {
			logWatcher.Err <- fmt.Errorf("error backtracking to previous journal entry")
			return
		}
		// Walk backward.
		for lines > 0 {
			// Stop if the entry time is before our cutoff.
			// We'll need the entry time if it isn't, so go
			// ahead and parse it now.
			if C.sd_journal_get_realtime_usec(j, &stamp) != 0 {
				break
			} else {
				// Compare the timestamp on the entry
				// to our threshold value.
				if sinceUnixMicro != 0 && sinceUnixMicro > uint64(stamp) {
					break
				}
			}
			lines--
			// If we're at the start of the journal, or
			// don't need to back up past any more entries,
			// stop.
			if lines == 0 || C.sd_journal_previous(j) <= 0 {
				break
			}
		}
	} else {
		// Start at the beginning of the journal.
		if C.sd_journal_seek_head(j) < 0 {
			logWatcher.Err <- fmt.Errorf("error seeking to start of journal")
			return
		}
		// If we have a cutoff date, fast-forward to it.
		if sinceUnixMicro != 0 && C.sd_journal_seek_realtime_usec(j, C.uint64_t(sinceUnixMicro)) != 0 {
			logWatcher.Err <- fmt.Errorf("error seeking to start time in journal")
			return
		}
		if C.sd_journal_next(j) < 0 {
			logWatcher.Err <- fmt.Errorf("error skipping to next journal entry")
			return
		}
	}
	cursor = s.drainJournal(logWatcher, config, j, "")
	if config.Follow {
		// Allocate a descriptor for following the journal, if we'll
		// need one.  Do it here so that we can report if it fails.
		if fd := C.sd_journal_get_fd(j); fd < C.int(0) {
			logWatcher.Err <- fmt.Errorf("error opening journald follow descriptor: %q", C.GoString(C.strerror(-fd)))
		} else {
			// Create a pipe that we can poll at the same time as
			// the journald descriptor.
			if C.pipe(&pipes[0]) == C.int(-1) {
				logWatcher.Err <- fmt.Errorf("error opening journald close notification pipe")
			} else {
				s.followJournal(logWatcher, config, j, pipes, cursor)
				// Let followJournal handle freeing the journal context
				// object and closing the channel.
				following = true
			}
		}
	}
	return
}