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 <pehunt@redhat.com>

1 files changed, 21 insertions, 4 deletions

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