[FEATURE] [BREAKING] Support writing logs in a file. (#686)

* [FEATURE] Support writing logs in a file.

* Add documentation about logs file path.

* Rename logs_level and logs_file_path into log_level and log_file_path.

* Update BREAKING.md

Fixes #338

Co-authored-by: Amir Zarrinkafsh <nightah@me.com>

27 files changed, 108 insertions, 40 deletions

diff --git a/BREAKING.md b/BREAKING.md
index e11d3b9e2..bc341323b 100644
--- a/BREAKING.md
+++ b/BREAKING.md
@@ -6,6 +6,10 @@ recommended not to use the 'latest' Docker image tag blindly but pick a version
 and read this documentation before upgrading. This is where you will get information about
 breaking changes and about what you should do to overcome those changes.
 
+## Breaking in v4.7.0
+
+`logs_level` configuration key has been renamed to `log_level`.
+
 ## Breaking in v4.0.0
 
 Authelia has been rewritten in Go for better code maintainability and for performance and
diff --git a/cmd/authelia/main.go b/cmd/authelia/main.go
index 5dd849458..2ed6592a8 100644
--- a/cmd/authelia/main.go
+++ b/cmd/authelia/main.go
@@ -29,10 +29,6 @@ func startServer() {
 		log.Fatal(errors.New("No config file path provided"))
 	}
 
-	if os.Getenv("ENVIRONMENT") == "dev" {
-		logging.Logger().Info("===> Authelia is running in development mode. <===")
-	}
-
 	config, errs := configuration.Read(configPathFlag)
 
 	if len(errs) > 0 {
@@ -42,7 +38,11 @@ func startServer() {
 		panic(errors.New("Some errors have been reported"))
 	}
 
-	switch config.LogsLevel {
+	if err := logging.InitializeLogger(config.LogFilePath); err != nil {
+		log.Fatalf("Cannot initialize logger: %v", err)
+	}
+
+	switch config.LogLevel {
 	case "info":
 		logging.Logger().Info("Logging severity set to info")
 		logging.SetLevel(logrus.InfoLevel)
@@ -56,6 +56,10 @@ func startServer() {
 		logging.SetLevel(logrus.TraceLevel)
 	}
 
+	if os.Getenv("ENVIRONMENT") == "dev" {
+		logging.Logger().Info("===> Authelia is running in development mode. <===")
+	}
+
 	var userProvider authentication.UserProvider
 
 	if config.AuthenticationBackend.File != nil {
diff --git a/config.template.yml b/config.template.yml
index 6cdb1c5d5..dd063f53c 100644
--- a/config.template.yml
+++ b/config.template.yml
@@ -9,7 +9,9 @@ port: 9091
 # tls_cert: /var/lib/authelia/ssl/cert.pem
 
 # Level of verbosity for logs: info, debug, trace
-logs_level: debug
+log_level: debug
+## File path where the logs will be written. If not set logs are written to stdout.
+# log_file_path: /var/log/authelia
 
 # The secret used to generate JWT tokens when validating user identity by
 # email confirmation.
diff --git a/docs/configuration/miscellaneous.md b/docs/configuration/miscellaneous.md
index 246a55c42..824313b60 100644
--- a/docs/configuration/miscellaneous.md
+++ b/docs/configuration/miscellaneous.md
@@ -29,14 +29,25 @@ following configuration options:
     tls_cert: /var/lib/authelia/ssl/cert.pem
 
 
-## Logs level
+## Log
+
+### Log level
 
 `optional: true`
 
 Defines the level of logs used by Authelia. This level can be set to
 `trace`, `debug`, `info`.
 
-    logs_level: debug
+    log_level: debug
+
+### Log file path
+
+`optional: true`
+
+Logs can be stored in a file when file path is provided. Otherwise logs
+are written to standard output.
+
+    log_file_path: /var/log/authelia.log
 
 
 ## JWT Secret
diff --git a/internal/configuration/reader_test.go b/internal/configuration/reader_test.go
index 5e455e611..92e0ce9ec 100644
--- a/internal/configuration/reader_test.go
+++ b/internal/configuration/reader_test.go
@@ -23,7 +23,7 @@ func TestShouldParseConfigFile(t *testing.T) {
 	require.Len(t, errors, 0)
 
 	assert.Equal(t, 9091, config.Port)
-	assert.Equal(t, "debug", config.LogsLevel)
+	assert.Equal(t, "debug", config.LogLevel)
 	assert.Equal(t, "https://home.example.com:8080/", config.DefaultRedirectionURL)
 	assert.Equal(t, "authelia.com", config.TOTP.Issuer)
 	assert.Equal(t, "secret_from_env", config.JWTSecret)
diff --git a/internal/configuration/schema/configuration.go b/internal/configuration/schema/configuration.go
index d7c518cac..f4178ca7e 100644
--- a/internal/configuration/schema/configuration.go
+++ b/internal/configuration/schema/configuration.go
@@ -7,7 +7,8 @@ type Configuration struct {
 	TLSCert string `mapstructure:"tls_cert"`
 	TLSKey  string `mapstructure:"tls_key"`
 
-	LogsLevel string `mapstructure:"logs_level"`
+	LogLevel    string `mapstructure:"log_level"`
+	LogFilePath string `mapstructure:"log_file_path"`
 
 	// This secret is used by the identity validation process to forge JWT tokens
 	// representing the permission to proceed with the operation.
diff --git a/internal/configuration/test_resources/config.yml b/internal/configuration/test_resources/config.yml
index 8bedc2845..833cadd15 100644
--- a/internal/configuration/test_resources/config.yml
+++ b/internal/configuration/test_resources/config.yml
@@ -5,7 +5,7 @@
 host: 127.0.0.1
 port: 9091
 
-logs_level: debug
+log_level: debug
 default_redirection_url: https://home.example.com:8080/
 
 totp:
diff --git a/internal/configuration/validator/configuration.go b/internal/configuration/validator/configuration.go
index 2e9934bcf..890b2bdc6 100644
--- a/internal/configuration/validator/configuration.go
+++ b/internal/configuration/validator/configuration.go
@@ -8,7 +8,7 @@ import (
 )
 
 var defaultPort = 8080
-var defaultLogsLevel = "info"
+var defaultLogLevel = "info"
 
 // Validate and adapt the configuration read from file.
 func Validate(configuration *schema.Configuration, validator *schema.StructValidator) {
@@ -20,8 +20,8 @@ func Validate(configuration *schema.Configuration, validator *schema.StructValid
 		configuration.Port = defaultPort
 	}
 
-	if configuration.LogsLevel == "" {
-		configuration.LogsLevel = defaultLogsLevel
+	if configuration.LogLevel == "" {
+		configuration.LogLevel = defaultLogLevel
 	}
 
 	if configuration.TLSKey != "" && configuration.TLSCert == "" {
diff --git a/internal/configuration/validator/configuration_test.go b/internal/configuration/validator/configuration_test.go
index 24faa68b4..83c6d6f59 100644
--- a/internal/configuration/validator/configuration_test.go
+++ b/internal/configuration/validator/configuration_test.go
@@ -12,7 +12,7 @@ func newDefaultConfig() schema.Configuration {
 	config := schema.Configuration{}
 	config.Host = "127.0.0.1"
 	config.Port = 9090
-	config.LogsLevel = "info"
+	config.LogLevel = "info"
 	config.JWTSecret = "a_secret"
 	config.AuthenticationBackend.File = new(schema.FileAuthenticationBackendConfiguration)
 	config.AuthenticationBackend.File.Path = "/a/path"
@@ -40,7 +40,7 @@ func TestShouldNotUpdateConfig(t *testing.T) {
 
 	require.Len(t, validator.Errors(), 0)
 	assert.Equal(t, 9090, config.Port)
-	assert.Equal(t, "info", config.LogsLevel)
+	assert.Equal(t, "info", config.LogLevel)
 }
 
 func TestShouldValidateAndUpdatePort(t *testing.T) {
@@ -68,12 +68,12 @@ func TestShouldValidateAndUpdateHost(t *testing.T) {
 func TestShouldValidateAndUpdateLogsLevel(t *testing.T) {
 	validator := schema.NewStructValidator()
 	config := newDefaultConfig()
-	config.LogsLevel = ""
+	config.LogLevel = ""
 
 	Validate(&config, validator)
 
 	require.Len(t, validator.Errors(), 0)
-	assert.Equal(t, "info", config.LogsLevel)
+	assert.Equal(t, "info", config.LogLevel)
 }
 
 func TestShouldEnsureNotifierConfigIsProvided(t *testing.T) {
diff --git a/internal/logging/logger.go b/internal/logging/logger.go
index e83c31781..1d9338bf8 100644
--- a/internal/logging/logger.go
+++ b/internal/logging/logger.go
@@ -1,16 +1,12 @@
 package logging
 
 import (
+	"os"
+
 	logrus_stack "github.com/Gurpartap/logrus-stack"
 	"github.com/sirupsen/logrus"
 )
 
-func init() {
-	callerLevels := []logrus.Level{}
-	stackLevels := []logrus.Level{logrus.PanicLevel, logrus.FatalLevel, logrus.ErrorLevel}
-	logrus.AddHook(logrus_stack.NewHook(callerLevels, stackLevels))
-}
-
 // Logger return the standard logrus logger.
 func Logger() *logrus.Logger {
 	return logrus.StandardLogger()
@@ -20,3 +16,19 @@ func Logger() *logrus.Logger {
 func SetLevel(level logrus.Level) {
 	logrus.SetLevel(level)
 }
+
+// InitializeLogger initialize logger
+func InitializeLogger(filename string) error {
+	callerLevels := []logrus.Level{}
+	stackLevels := []logrus.Level{logrus.PanicLevel, logrus.FatalLevel, logrus.ErrorLevel}
+	logrus.AddHook(logrus_stack.NewHook(callerLevels, stackLevels))
+
+	if filename != "" {
+		f, err := os.OpenFile(filename, os.O_WRONLY|os.O_CREATE, 0600)
+		if err != nil {
+			return err
+		}
+		logrus.SetOutput(f)
+	}
+	return nil
+}
diff --git a/internal/logging/logger_test.go b/internal/logging/logger_test.go
new file mode 100644
index 000000000..6a92ca874
--- /dev/null
+++ b/internal/logging/logger_test.go
@@ -0,0 +1,34 @@
+package logging
+
+import (
+	"fmt"
+	"io/ioutil"
+	"log"
+	"os"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+func TestShouldWriteLogsToFile(t *testing.T) {
+	dir, err := ioutil.TempDir("/tmp", "logs-dir")
+	if err != nil {
+		log.Fatal(err)
+	}
+	defer os.RemoveAll(dir)
+
+	path := fmt.Sprintf("%s/authelia.log", dir)
+	err = InitializeLogger(path)
+	require.NoError(t, err)
+
+	Logger().Info("This is a test")
+
+	f, err := os.OpenFile(path, os.O_RDONLY, 0)
+	require.NoError(t, err)
+
+	b, err := ioutil.ReadAll(f)
+	require.NoError(t, err)
+
+	assert.Contains(t, string(b), "level=info msg=\"This is a test\"\n")
+}
diff --git a/internal/suites/BypassAll/configuration.yml b/internal/suites/BypassAll/configuration.yml
index 1ef411b6e..de4fe375c 100644
--- a/internal/suites/BypassAll/configuration.yml
+++ b/internal/suites/BypassAll/configuration.yml
@@ -4,7 +4,7 @@
 
 port: 9091
 
-logs_level: debug
+log_level: debug
 
 jwt_secret: unsecure_secret
 
diff --git a/internal/suites/Docker/configuration.yml b/internal/suites/Docker/configuration.yml
index 7e861d7de..0b1abef1d 100644
--- a/internal/suites/Docker/configuration.yml
+++ b/internal/suites/Docker/configuration.yml
@@ -4,7 +4,7 @@
 
 port: 9091
 
-logs_level: debug
+log_level: debug
 
 default_redirection_url: https://home.example.com:8080/
 
diff --git a/internal/suites/DuoPush/configuration.yml b/internal/suites/DuoPush/configuration.yml
index 343f4d52d..028d3df7d 100644
--- a/internal/suites/DuoPush/configuration.yml
+++ b/internal/suites/DuoPush/configuration.yml
@@ -4,7 +4,7 @@
 
 port: 9091
 
-logs_level: trace
+log_level: trace
 
 default_redirection_url: https://home.example.com:8080/
 
diff --git a/internal/suites/HAProxy/configuration.yml b/internal/suites/HAProxy/configuration.yml
index a69c05991..54283cd34 100644
--- a/internal/suites/HAProxy/configuration.yml
+++ b/internal/suites/HAProxy/configuration.yml
@@ -4,7 +4,7 @@
 
 port: 9091
 
-logs_level: debug
+log_level: debug
 
 jwt_secret: unsecure_secret
 
diff --git a/internal/suites/HighAvailability/configuration.yml b/internal/suites/HighAvailability/configuration.yml
index b3608e2cc..facf8edd7 100644
--- a/internal/suites/HighAvailability/configuration.yml
+++ b/internal/suites/HighAvailability/configuration.yml
@@ -8,7 +8,7 @@ port: 9091
 # Log level
 #
 # Level of verbosity for logs
-logs_level: debug
+log_level: debug
 
 jwt_secret: unsecure_secret
 
diff --git a/internal/suites/LDAP/configuration.yml b/internal/suites/LDAP/configuration.yml
index 9d17e4076..6fb61a9eb 100644
--- a/internal/suites/LDAP/configuration.yml
+++ b/internal/suites/LDAP/configuration.yml
@@ -4,7 +4,7 @@
 
 port: 9091
 
-logs_level: debug
+log_level: debug
 
 default_redirection_url: https://home.example.com:8080/
 
diff --git a/internal/suites/Mariadb/configuration.yml b/internal/suites/Mariadb/configuration.yml
index 5daa83cbb..c67052bc1 100644
--- a/internal/suites/Mariadb/configuration.yml
+++ b/internal/suites/Mariadb/configuration.yml
@@ -4,7 +4,7 @@
 
 port: 9091
 
-logs_level: debug
+log_level: debug
 
 default_redirection_url: https://home.example.com:8080/
 
diff --git a/internal/suites/MySQL/configuration.yml b/internal/suites/MySQL/configuration.yml
index cdf215996..7d521eea8 100644
--- a/internal/suites/MySQL/configuration.yml
+++ b/internal/suites/MySQL/configuration.yml
@@ -4,7 +4,7 @@
 
 port: 9091
 
-logs_level: debug
+log_level: debug
 
 default_redirection_url: https://home.example.com:8080/
 
diff --git a/internal/suites/NetworkACL/configuration.yml b/internal/suites/NetworkACL/configuration.yml
index 8a79c1677..e10b8d297 100644
--- a/internal/suites/NetworkACL/configuration.yml
+++ b/internal/suites/NetworkACL/configuration.yml
@@ -4,7 +4,7 @@
 
 port: 9091
 
-logs_level: debug
+log_level: debug
 
 jwt_secret: unsecure_password
 
diff --git a/internal/suites/OneFactorOnly/configuration.yml b/internal/suites/OneFactorOnly/configuration.yml
index eb8c17279..5ff1e87fe 100644
--- a/internal/suites/OneFactorOnly/configuration.yml
+++ b/internal/suites/OneFactorOnly/configuration.yml
@@ -4,7 +4,7 @@
 
 port: 9091
 
-logs_level: debug
+log_level: debug
 
 default_redirection_url: https://home.example.com:8080/
 
diff --git a/internal/suites/Postgres/configuration.yml b/internal/suites/Postgres/configuration.yml
index c75dabd05..a33794a2a 100644
--- a/internal/suites/Postgres/configuration.yml
+++ b/internal/suites/Postgres/configuration.yml
@@ -4,7 +4,7 @@
 
 port: 9091
 
-logs_level: debug
+log_level: debug
 
 default_redirection_url: https://home.example.com:8080/
 
diff --git a/internal/suites/ShortTimeouts/configuration.yml b/internal/suites/ShortTimeouts/configuration.yml
index 9988c1d3c..05cdb71cb 100644
--- a/internal/suites/ShortTimeouts/configuration.yml
+++ b/internal/suites/ShortTimeouts/configuration.yml
@@ -4,7 +4,7 @@
 
 port: 9091
 
-logs_level: debug
+log_level: debug
 
 jwt_secret: unsecure_secret
 
diff --git a/internal/suites/Standalone/configuration.yml b/internal/suites/Standalone/configuration.yml
index 4fe68db98..91aa67dec 100644
--- a/internal/suites/Standalone/configuration.yml
+++ b/internal/suites/Standalone/configuration.yml
@@ -6,7 +6,7 @@ port: 9091
 tls_cert: /var/lib/authelia/ssl/cert.pem
 tls_key: /var/lib/authelia/ssl/key.pem
 
-logs_level: debug
+log_level: debug
 
 authentication_backend:
   file:
diff --git a/internal/suites/Traefik/configuration.yml b/internal/suites/Traefik/configuration.yml
index b0343f775..1c849b8ea 100644
--- a/internal/suites/Traefik/configuration.yml
+++ b/internal/suites/Traefik/configuration.yml
@@ -4,7 +4,7 @@
 
 port: 9091
 
-logs_level: debug
+log_level: debug
 
 jwt_secret: unsecure_secret
 
diff --git a/internal/suites/Traefik2/configuration.yml b/internal/suites/Traefik2/configuration.yml
index b0343f775..1c849b8ea 100644
--- a/internal/suites/Traefik2/configuration.yml
+++ b/internal/suites/Traefik2/configuration.yml
@@ -4,7 +4,7 @@
 
 port: 9091
 
-logs_level: debug
+log_level: debug
 
 jwt_secret: unsecure_secret
 
diff --git a/internal/suites/example/kube/authelia/configs/configuration.yml b/internal/suites/example/kube/authelia/configs/configuration.yml
index 97fae4378..3fa78e4e4 100644
--- a/internal/suites/example/kube/authelia/configs/configuration.yml
+++ b/internal/suites/example/kube/authelia/configs/configuration.yml
@@ -3,7 +3,7 @@
 ###############################################################
 
 port: 80
-logs_level: debug
+log_level: debug
 
 default_redirection_url: https://home.example.com:8080