From 84015df635a0032e9dce0a42c47bfab7743cdc4a Mon Sep 17 00:00:00 2001
From: Jonathan Buch <jbuch@synyx.de>
Date: Wed, 20 May 2020 08:42:02 +0200
Subject: [PATCH] Add systemd journal handler

---
 go.mod                         |  1 +
 go.sum                         |  3 +++
 handlers/journal/systemdlog.go | 47 ++++++++++++++++++++++++++++++++++
 3 files changed, 51 insertions(+)
 create mode 100644 handlers/journal/systemdlog.go

diff --git a/go.mod b/go.mod
index 40ca197..621af1f 100644
--- a/go.mod
+++ b/go.mod
@@ -8,6 +8,7 @@ require (
 	github.com/aphistic/sweet v0.2.0 // indirect
 	github.com/aws/aws-sdk-go v1.20.6
 	github.com/aybabtme/rgbterm v0.0.0-20170906152045-cc83f3b3ce59
+	github.com/coreos/go-systemd/v22 v22.0.0
 	github.com/fatih/color v1.7.0
 	github.com/go-logfmt/logfmt v0.4.0
 	github.com/golang/protobuf v1.3.1 // indirect
diff --git a/go.sum b/go.sum
index f367e3e..aeaa0ef 100644
--- a/go.sum
+++ b/go.sum
@@ -8,6 +8,8 @@ github.com/aws/aws-sdk-go v1.20.6 h1:kmy4Gvdlyez1fV4kw5RYxZzWKVyuHZHgPWeU/YvRsV4
 github.com/aws/aws-sdk-go v1.20.6/go.mod h1:KmX6BPdI08NWTb3/sm4ZGu5ShLoqVDhKgpiN924inxo=
 github.com/aybabtme/rgbterm v0.0.0-20170906152045-cc83f3b3ce59 h1:WWB576BN5zNSZc/M9d/10pqEx5VHNhaQ/yOVAkmj5Yo=
 github.com/aybabtme/rgbterm v0.0.0-20170906152045-cc83f3b3ce59/go.mod h1:q/89r3U2H7sSsE2t6Kca0lfwTK8JdoNGS/yzM/4iH5I=
+github.com/coreos/go-systemd/v22 v22.0.0 h1:XJIw/+VlJ+87J+doOxznsAWIdmWuViOVhkQamW5YV28=
+github.com/coreos/go-systemd/v22 v22.0.0/go.mod h1:xO0FLkIi5MaZafQlIrOotqXZ90ih+1atmu1JpKERPPk=
 github.com/davecgh/go-spew v1.1.0 h1:ZDRjVQ15GmhC3fiQ8ni8+OwkZQO4DARzQgrnXU1Liz8=
 github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
@@ -18,6 +20,7 @@ github.com/fsnotify/fsnotify v1.4.7 h1:IXs+QLmnXW2CcXuY+8Mzv/fWEsPGWxqefPtCP5CnV
 github.com/fsnotify/fsnotify v1.4.7/go.mod h1:jwhsz4b93w/PPRr/qN1Yymfu8t87LnFCMoQvtojpjFo=
 github.com/go-logfmt/logfmt v0.4.0 h1:MP4Eh7ZCb31lleYCFuwm0oe4/YGak+5l1vA2NOE80nA=
 github.com/go-logfmt/logfmt v0.4.0/go.mod h1:3RMwSq7FuexP4Kalkev3ejPJsZTpXXBr9+V4qmtdjCk=
+github.com/godbus/dbus/v5 v5.0.3/go.mod h1:xhWf0FNVPg57R7Z0UbKHbJfkEywrmjJnf7w5xrFpKfA=
 github.com/golang/protobuf v1.2.0 h1:P3YflyNX/ehuJFLhxviNdFxQPkGK5cDcApsge1SqnvM=
 github.com/golang/protobuf v1.2.0/go.mod h1:6lQm79b+lXiMfvg/cZm0SGofjICqVBUtrP5yJMmIC1U=
 github.com/golang/protobuf v1.3.1 h1:YF8+flBXS5eO826T4nzqPrxfhQThhXl0YzfuUPu4SBg=
diff --git a/handlers/journal/systemdlog.go b/handlers/journal/systemdlog.go
new file mode 100644
index 0000000..a9ae4e4
--- /dev/null
+++ b/handlers/journal/systemdlog.go
@@ -0,0 +1,47 @@
+package journal
+
+import (
+	"errors"
+	"fmt"
+
+	"github.com/apex/log"
+	"github.com/coreos/go-systemd/v22/journal"
+)
+
+// Handler implementation.
+type Handler struct {
+}
+
+// New handler.
+func New() *Handler {
+	return &Handler{}
+}
+
+// HandleLog implements log.Handler.
+func (h *Handler) HandleLog(e *log.Entry) error {
+
+	fields := make(map[string]string, len(e.Fields))
+	for k, v := range e.Fields {
+		fields[k] = fmt.Sprint(v)
+	}
+
+	switch e.Level {
+	case log.DebugLevel:
+		return journal.Send(e.Message, journal.PriDebug, fields)
+	case log.InfoLevel:
+		return journal.Send(e.Message, journal.PriInfo, fields)
+	case log.WarnLevel:
+		return journal.Send(e.Message, journal.PriWarning, fields)
+	case log.ErrorLevel:
+		return journal.Send(e.Message, journal.PriErr, fields)
+	case log.FatalLevel:
+		return journal.Send(e.Message, journal.PriCrit, fields)
+	}
+
+	return errors.New("unknown log level given for systemd")
+}
+
+// Close shuts down the handler.
+func (h *Handler) Close() error {
+	return nil
+}