From a7ab91c2d16837ecf8904a95702d08ea433f2790 Mon Sep 17 00:00:00 2001
From: dmachard <5562930+dmachard@users.noreply.github.com>
Date: Tue, 9 Nov 2021 22:45:45 +0100
Subject: [PATCH] syslog format: json support #8

---
 config.yml           |  2 ++
 dnsutils/config.go   | 12 ++++++++++++
 doc/configuration.md |  2 ++
 loggers/stdout.go    |  1 -
 loggers/syslog.go    | 15 ++++++++++++++-
 5 files changed, 30 insertions(+), 2 deletions(-)

diff --git a/config.yml b/config.yml
index dbb093a3..8bdd103c 100644
--- a/config.yml
+++ b/config.yml
@@ -239,6 +239,8 @@ loggers:
     # output text format, please refer to the default text format to see all available directives 
     # use this parameter if you want a specific format
     text-format: ""
+    # output format: text|json
+    mode: text
 
   fluentd:
     # to enable, set the enable to true
diff --git a/dnsutils/config.go b/dnsutils/config.go
index 2424cd50..c9633394 100644
--- a/dnsutils/config.go
+++ b/dnsutils/config.go
@@ -7,6 +7,16 @@ import (
 	"gopkg.in/yaml.v3"
 )
 
+func IsValidMode(mode string) bool {
+	switch mode {
+	case
+		"text",
+		"json":
+		return true
+	}
+	return false
+}
+
 type Config struct {
 	Trace struct {
 		Verbose    bool   `yaml:"verbose"`
@@ -122,6 +132,7 @@ type Config struct {
 			Transport     string `yaml:"transport"`
 			RemoteAddress string `yaml:"remote-address"`
 			TextFormat    string `yaml:"text-format"`
+			Mode          string `yaml:"mode"`
 		} `yaml:"syslog"`
 		Fluentd struct {
 			Enable        bool   `yaml:"enable"`
@@ -248,6 +259,7 @@ func (c *Config) SetDefault() {
 	c.Loggers.Syslog.Transport = "local"
 	c.Loggers.Syslog.RemoteAddress = "127.0.0.1:514"
 	c.Loggers.Syslog.TextFormat = ""
+	c.Loggers.Syslog.Mode = "text"
 
 	c.Loggers.Fluentd.Enable = false
 	c.Loggers.Fluentd.RemoteAddress = "127.0.0.1"
diff --git a/doc/configuration.md b/doc/configuration.md
index 09d45236..7eded616 100644
--- a/doc/configuration.md
+++ b/doc/configuration.md
@@ -495,6 +495,8 @@ syslog:
   # output text format, please refer to the default text format to see all available directives 
   # use this parameter if you want a specific format
   text-format: ""
+  # output format: text|json
+  mode: text
 ```
 
 ### Fluentd Client
diff --git a/loggers/stdout.go b/loggers/stdout.go
index 780329e2..3dbf9da1 100644
--- a/loggers/stdout.go
+++ b/loggers/stdout.go
@@ -36,7 +36,6 @@ func NewStdOut(config *dnsutils.Config, console *logger.Logger) *StdOut {
 }
 
 func (c *StdOut) ReadConfig() {
-	c.mode = c.config.Loggers.Stdout.Mode
 	if len(c.config.Loggers.Stdout.TextFormat) > 0 {
 		c.textFormat = strings.Fields(c.config.Loggers.Stdout.TextFormat)
 	} else {
diff --git a/loggers/syslog.go b/loggers/syslog.go
index 14484ba8..8aae21ee 100644
--- a/loggers/syslog.go
+++ b/loggers/syslog.go
@@ -1,6 +1,8 @@
 package loggers
 
 import (
+	"bytes"
+	"encoding/json"
 	"fmt"
 	"log/syslog"
 	"strings"
@@ -69,6 +71,9 @@ func NewSyslog(config *dnsutils.Config, console *logger.Logger) *Syslog {
 }
 
 func (c *Syslog) ReadConfig() {
+	if !dnsutils.IsValidMode(c.config.Loggers.Syslog.Mode) {
+		c.logger.Fatal("logger syslog - invalid mode text or json expected")
+	}
 	severity, err := GetPriority(c.config.Loggers.Syslog.Severity)
 	if err != nil {
 		c.logger.Fatal("logger syslog - invalid severity")
@@ -121,6 +126,8 @@ func (o *Syslog) Run() {
 
 	var syslogconn *syslog.Writer
 	var err error
+	buffer := new(bytes.Buffer)
+
 	if o.config.Loggers.Syslog.Transport == "local" {
 		syslogconn, err = syslog.New(o.facility|o.severity, "")
 		if err != nil {
@@ -135,7 +142,13 @@ func (o *Syslog) Run() {
 	o.syslogConn = syslogconn
 
 	for dm := range o.channel {
-		o.syslogConn.Write(dm.Bytes(o.textFormat))
+		switch o.config.Loggers.Syslog.Mode {
+		case "text":
+			o.syslogConn.Write(dm.Bytes(o.textFormat))
+		case "json":
+			json.NewEncoder(buffer).Encode(dm)
+			o.syslogConn.Write(buffer.Bytes())
+		}
 	}
 
 	o.LogInfo("run terminated")