From cd2ca137c0a58d3ee911e8ff3a67abe5d56214f6 Mon Sep 17 00:00:00 2001
From: Kristoffer Dalby <kradalby@kradalby.no>
Date: Thu, 5 Aug 2021 19:19:25 +0100
Subject: [PATCH] Make log_level user configurable

---
 README.md                  |  5 +++++
 cmd/headscale/cli/utils.go | 10 ++++++----
 cmd/headscale/headscale.go | 30 ++++++++++++++++++++++++++++--
 3 files changed, 39 insertions(+), 6 deletions(-)

diff --git a/README.md b/README.md
index aea8fd6a..cb42b666 100644
--- a/README.md
+++ b/README.md
@@ -119,6 +119,11 @@ Headscale's configuration file is named `config.json` or `config.yaml`. Headscal
 
 `server_url` is the external URL via which Headscale is reachable. `listen_addr` is the IP address and port the Headscale program should listen on. `ip_prefix` is the IP prefix (range) in which IP addresses for nodes will be allocated (default 100.64.0.0/10, e.g., 192.168.4.0/24, 10.0.0.0/8)
 
+```
+    "log_level": "debug"
+```
+`log_level` can be used to set the Log level for Headscale, it defaults to `debug`, and the available levels are: `trace`, `debug`, `info`, `warn` and `error`.
+
 ```
     "private_key_path": "private.key",
 ```
diff --git a/cmd/headscale/cli/utils.go b/cmd/headscale/cli/utils.go
index ddaeca73..d104f044 100644
--- a/cmd/headscale/cli/utils.go
+++ b/cmd/headscale/cli/utils.go
@@ -39,6 +39,8 @@ func LoadConfig(path string) error {
 
 	viper.SetDefault("ip_prefix", "100.64.0.0/10")
 
+	viper.SetDefault("log_level", "debug")
+
 	err := viper.ReadInConfig()
 	if err != nil {
 		return fmt.Errorf("Fatal error reading config file: %s \n", err)
@@ -170,24 +172,24 @@ func JsonOutput(result interface{}, errResult error, outputFormat string) {
 		if errResult != nil {
 			j, err = json.MarshalIndent(ErrorOutput{errResult.Error()}, "", "\t")
 			if err != nil {
-				log.Fatalln(err)
+				log.Fatal().Err(err)
 			}
 		} else {
 			j, err = json.MarshalIndent(result, "", "\t")
 			if err != nil {
-				log.Fatalln(err)
+				log.Fatal().Err(err)
 			}
 		}
 	case "json-line":
 		if errResult != nil {
 			j, err = json.Marshal(ErrorOutput{errResult.Error()})
 			if err != nil {
-				log.Fatalln(err)
+				log.Fatal().Err(err)
 			}
 		} else {
 			j, err = json.Marshal(result)
 			if err != nil {
-				log.Fatalln(err)
+				log.Fatal().Err(err)
 			}
 		}
 	}
diff --git a/cmd/headscale/headscale.go b/cmd/headscale/headscale.go
index c7b834c2..3769f534 100644
--- a/cmd/headscale/headscale.go
+++ b/cmd/headscale/headscale.go
@@ -1,15 +1,41 @@
 package main
 
 import (
-	"log"
+	"os"
+	"time"
 
 	"github.com/juanfont/headscale/cmd/headscale/cli"
+	"github.com/rs/zerolog"
+	"github.com/rs/zerolog/log"
+	"github.com/spf13/viper"
 )
 
 func main() {
+	zerolog.TimeFieldFormat = zerolog.TimeFormatUnix
+	log.Logger = log.Output(zerolog.ConsoleWriter{
+		Out:        os.Stdout,
+		TimeFormat: time.RFC3339,
+	})
+
 	err := cli.LoadConfig("")
 	if err != nil {
-		log.Fatalf(err.Error())
+		log.Fatal().Err(err)
+	}
+
+	logLevel := viper.GetString("log_level")
+	switch logLevel {
+	case "trace":
+		zerolog.SetGlobalLevel(zerolog.TraceLevel)
+	case "debug":
+		zerolog.SetGlobalLevel(zerolog.DebugLevel)
+	case "info":
+		zerolog.SetGlobalLevel(zerolog.InfoLevel)
+	case "warn":
+		zerolog.SetGlobalLevel(zerolog.WarnLevel)
+	case "error":
+		zerolog.SetGlobalLevel(zerolog.ErrorLevel)
+	default:
+		zerolog.SetGlobalLevel(zerolog.DebugLevel)
 	}
 
 	cli.Execute()