Merge pull request #3083 from openSUSE/systemd-optional

Add `systemd` build tag

4 files changed, 24 insertions, 3 deletions

diff --git a/libpod/events/events.go b/libpod/events/events.go
index 650a47bfb..1ec79bcd7 100644
--- a/libpod/events/events.go
+++ b/libpod/events/events.go
@@ -10,6 +10,10 @@ import (
 	"github.com/pkg/errors"
 )
 
+// ErrNoJournaldLogging indicates that there is no journald logging
+// supported (requires libsystemd)
+var ErrNoJournaldLogging = errors.New("No support for journald logging")
+
 // String returns a string representation of EventerType
 func (et EventerType) String() string {
 	if et == LogFile {
diff --git a/libpod/events/events_linux.go b/libpod/events/events_linux.go
index da5d7965e..11f309574 100644
--- a/libpod/events/events_linux.go
+++ b/libpod/events/events_linux.go
@@ -8,12 +8,14 @@ import (
 )
 
 // NewEventer creates an eventer based on the eventer type
-func NewEventer(options EventerOptions) (Eventer, error) {
-	var eventer Eventer
+func NewEventer(options EventerOptions) (eventer Eventer, err error) {
 	logrus.Debugf("Initializing event backend %s", options.EventerType)
 	switch strings.ToUpper(options.EventerType) {
 	case strings.ToUpper(Journald.String()):
-		eventer = EventJournalD{options}
+		eventer, err = newEventJournalD(options)
+		if err != nil {
+			return nil, errors.Wrapf(err, "eventer creation")
+		}
 	case strings.ToUpper(LogFile.String()):
 		eventer = EventLogFile{options}
 	default:
diff --git a/libpod/events/journal_linux.go b/libpod/events/journal_linux.go
index 8ba5bc2c7..264c84f89 100644
--- a/libpod/events/journal_linux.go
+++ b/libpod/events/journal_linux.go
@@ -1,3 +1,5 @@
+// +build systemd
+
 package events
 
 import (
@@ -15,6 +17,11 @@ type EventJournalD struct {
 	options EventerOptions
 }
 
+// newEventJournalD creates a new journald Eventer
+func newEventJournalD(options EventerOptions) (Eventer, error) {
+	return EventJournalD{options}, nil
+}
+
 // Write to journald
 func (e EventJournalD) Write(ee Event) error {
 	m := make(map[string]string)
diff --git a/libpod/events/journal_unsupported.go b/libpod/events/journal_unsupported.go
new file mode 100644
index 000000000..c91d81f12
--- /dev/null
+++ b/libpod/events/journal_unsupported.go
@@ -0,0 +1,8 @@
+// +build !systemd
+
+package events
+
+// newEventJournalD always returns an error if libsystemd not found
+func newEventJournalD(options EventerOptions) (Eventer, error) {
+	return nil, ErrNoJournaldLogging
+}