feat: add support for LOG_LEVEL env variable (#942)

backend/go.mod

@@ -10,6 +10,7 @@ require (
 	github.com/emersion/go-sasl v0.0.0-20200509203442-7bfe0ed36a21
 	github.com/emersion/go-smtp v0.21.3
 	github.com/fxamacker/cbor/v2 v2.9.0
+	github.com/gin-contrib/slog v1.1.0
 	github.com/gin-gonic/gin v1.10.1
 	github.com/glebarez/go-sqlite v1.22.0
 	github.com/glebarez/sqlite v1.11.0
@@ -29,7 +30,6 @@ require (
 	github.com/mileusna/useragent v1.3.5
 	github.com/orandin/slog-gorm v1.4.0
 	github.com/oschwald/maxminddb-golang/v2 v2.0.0-beta.8
-	github.com/samber/slog-gin v1.15.1
 	github.com/spf13/cobra v1.9.1
 	github.com/stretchr/testify v1.10.0
 	go.opentelemetry.io/contrib/bridges/otelslog v0.12.0
@@ -45,6 +45,7 @@ require (
 	go.opentelemetry.io/otel/trace v1.37.0
 	golang.org/x/crypto v0.41.0
 	golang.org/x/image v0.30.0
+	golang.org/x/sync v0.16.0
 	golang.org/x/text v0.28.0
 	golang.org/x/time v0.12.0
 	gorm.io/driver/postgres v1.6.0
@@ -135,7 +136,6 @@ require (
 	golang.org/x/exp v0.0.0-20250813145105-42675adae3e6 // indirect
 	golang.org/x/net v0.43.0 // indirect
 	golang.org/x/oauth2 v0.27.0 // indirect
-	golang.org/x/sync v0.16.0 // indirect
 	golang.org/x/sys v0.35.0 // indirect
 	google.golang.org/genproto/googleapis/api v0.0.0-20250218202821-56aae31c358a // indirect
 	google.golang.org/genproto/googleapis/rpc v0.0.0-20250218202821-56aae31c358a // indirect

backend/go.sum

@@ -56,6 +56,8 @@ github.com/fxamacker/cbor/v2 v2.9.0 h1:NpKPmjDBgUfBms6tr6JZkTHtfFGcMKsw3eGcmD/sa
 github.com/fxamacker/cbor/v2 v2.9.0/go.mod h1:vM4b+DJCtHn+zz7h3FFp/hDAI9WNWCsZj23V5ytsSxQ=
 github.com/gabriel-vasile/mimetype v1.4.9 h1:5k+WDwEsD9eTLL8Tz3L0VnmVh9QxGjRmjBvAG7U/oYY=
 github.com/gabriel-vasile/mimetype v1.4.9/go.mod h1:WnSQhFKJuBlRyLiKohA/2DtIlPFAbguNaG7QCHcyGok=
+github.com/gin-contrib/slog v1.1.0 h1:K9MVNrETT6r/C3u2Aheer/gxwVeVqrGL0hXlsmv3fm4=
+github.com/gin-contrib/slog v1.1.0/go.mod h1:PvNXQVXcVOAaaiJR84LV1/xlQHIaXi9ygEXyBkmjdkY=
 github.com/gin-contrib/sse v1.1.0 h1:n0w2GMuUpWDVp7qSpvze6fAu9iRxJY4Hmj6AmBOU05w=
 github.com/gin-contrib/sse v1.1.0/go.mod h1:hxRZ5gVpWMT7Z0B0gSNYqqsSCNIJMjzvm6fqCz9vjwM=
 github.com/gin-gonic/gin v1.10.1 h1:T0ujvqyCSqRopADpgPgiTT63DUQVSfojyME59Ei63pQ=
@@ -241,8 +243,6 @@ github.com/robfig/cron/v3 v3.0.1/go.mod h1:eQICP3HwyT7UooqI/z+Ov+PtYAWygg1TEWWzG
 github.com/rogpeppe/go-internal v1.13.1 h1:KvO1DLK/DRN07sQ1LQKScxyZJuNnedQ5/wKSR38lUII=
 github.com/rogpeppe/go-internal v1.13.1/go.mod h1:uMEvuHeurkdAXX61udpOXGD/AzZDWNMNyH2VO9fmH0o=
 github.com/russross/blackfriday/v2 v2.1.0/go.mod h1:+Rmxgy9KzJVeS9/2gXHxylqXiyQDYRxCVz55jmeOWTM=
-github.com/samber/slog-gin v1.15.1 h1:jsnfr+S5HQPlz9pFPA3tOmKW7wN/znyZiE6hncucrTM=
-github.com/samber/slog-gin v1.15.1/go.mod h1:mPAEinK/g2jPLauuWO11m3Q0Ca7aG4k9XjXjXY8IhMQ=
 github.com/segmentio/asm v1.2.0 h1:9BQrFxC+YOHJlTlHGkTrFWf59nbL3XnCoFLTwDCI7ys=
 github.com/segmentio/asm v1.2.0/go.mod h1:BqMnlJP91P8d+4ibuonYZw9mfnzI9HfxselHZr5aAcs=
 github.com/spf13/cobra v1.9.1 h1:CXSaggrXdbHK9CF+8ywj8Amf7PBRmPCOJugH954Nnlo=

backend/internal/bootstrap/db_bootstrap.go

@@ -422,17 +422,18 @@ func getGormLogger() gormLogger.Interface {
 		slogGorm.WithErrorField("error"),
 	)
 
-	if common.EnvConfig.AppEnv == "production" {
-		loggerOpts = append(loggerOpts,
-			slogGorm.SetLogLevel(slogGorm.DefaultLogType, slog.LevelWarn),
-			slogGorm.WithIgnoreTrace(),
-		)
-	} else {
+	if common.EnvConfig.LogLevel == "debug" {
 		loggerOpts = append(loggerOpts,
 			slogGorm.SetLogLevel(slogGorm.DefaultLogType, slog.LevelDebug),
 			slogGorm.WithRecordNotFoundError(),
 			slogGorm.WithTraceAll(),
 		)
+
+	} else {
+		loggerOpts = append(loggerOpts,
+			slogGorm.SetLogLevel(slogGorm.DefaultLogType, slog.LevelWarn),
+			slogGorm.WithIgnoreTrace(),
+		)
 	}
 
 	return slogGorm.New(loggerOpts...)

backend/internal/bootstrap/observability_boostrap.go

@@ -8,6 +8,8 @@ import (
 	"os"
 	"time"
 
+	sloggin "github.com/gin-contrib/slog"
+
 	"github.com/lmittmann/tint"
 	"github.com/mattn/go-isatty"
 	"go.opentelemetry.io/contrib/bridges/otelslog"
@@ -89,28 +91,19 @@ func initOtelLogging(ctx context.Context, resource *resource.Resource) error {
 		return fmt.Errorf("failed to initialize OpenTelemetry log exporter: %w", err)
 	}
 
-	level := slog.LevelDebug
-	if common.EnvConfig.AppEnv == "production" {
-		level = slog.LevelInfo
-	}
+	level, _ := sloggin.ParseLevel(common.EnvConfig.LogLevel)
 
 	// Create the handler
 	var handler slog.Handler
-	switch {
-	case common.EnvConfig.LogJSON:
-		// Log as JSON if configured
+	if common.EnvConfig.LogJSON {
 		handler = slog.NewJSONHandler(os.Stdout, &slog.HandlerOptions{
 			Level: level,
 		})
-	case isatty.IsTerminal(os.Stdout.Fd()):
-		// Enable colors if we have a TTY
+	} else {
 		handler = tint.NewHandler(os.Stdout, &tint.Options{
-			TimeFormat: time.StampMilli,
-			Level:      level,
-		})
-	default:
-		handler = slog.NewTextHandler(os.Stdout, &slog.HandlerOptions{
+			TimeFormat: time.Stamp,
 			Level:      level,
+			NoColor:    !isatty.IsTerminal(os.Stdout.Fd()),
 		})
 	}
 

backend/internal/bootstrap/router_bootstrap.go

@@ -12,8 +12,8 @@ import (
 	"strings"
 	"time"
 
+	sloggin "github.com/gin-contrib/slog"
 	"github.com/gin-gonic/gin"
-	sloggin "github.com/samber/slog-gin"
 	"go.opentelemetry.io/contrib/instrumentation/github.com/gin-gonic/gin/otelgin"
 	"golang.org/x/time/rate"
 	"gorm.io/gorm"
@@ -49,30 +49,8 @@ func initRouterInternal(db *gorm.DB, svc *services) (utils.Service, error) {
 		gin.SetMode(gin.TestMode)
 	}
 
-	// do not log these URLs
-	loggerSkipPathsPrefix := []string{
-		"GET /application-configuration/logo",
-		"GET /application-configuration/background-image",
-		"GET /application-configuration/favicon",
-		"GET /_app",
-		"GET /fonts",
-		"GET /healthz",
-		"HEAD /healthz",
-	}
-
 	r := gin.New()
-	r.Use(sloggin.NewWithConfig(slog.Default(), sloggin.Config{
-		Filters: []sloggin.Filter{
-			func(c *gin.Context) bool {
-				for _, prefix := range loggerSkipPathsPrefix {
-					if strings.HasPrefix(c.Request.Method+" "+c.Request.URL.String(), prefix) {
-						return false
-					}
-				}
-				return true
-			},
-		},
-	}))
+	initLogger(r)
 
 	if !common.EnvConfig.TrustProxy {
 		_ = r.SetTrustedProxies(nil)
@@ -200,3 +178,29 @@ func initRouterInternal(db *gorm.DB, svc *services) (utils.Service, error) {
 
 	return runFn, nil
 }
+
+func initLogger(r *gin.Engine) {
+	loggerSkipPathsPrefix := []string{
+		"GET /api/application-configuration/logo",
+		"GET /api/application-configuration/background-image",
+		"GET /api/application-configuration/favicon",
+		"GET /_app",
+		"GET /fonts",
+		"GET /healthz",
+		"HEAD /healthz",
+	}
+
+	r.Use(sloggin.SetLogger(
+		sloggin.WithLogger(func(_ *gin.Context, _ *slog.Logger) *slog.Logger {
+			return slog.Default()
+		}),
+		sloggin.WithSkipper(func(c *gin.Context) bool {
+			for _, prefix := range loggerSkipPathsPrefix {
+				if strings.HasPrefix(c.Request.Method+" "+c.Request.URL.String(), prefix) {
+					return true
+				}
+			}
+			return false
+		}),
+	))
+}

backend/internal/common/env_config.go

@@ -10,6 +10,7 @@ import (
 	"strings"
 
 	"github.com/caarlos0/env/v11"
+	sloggin "github.com/gin-contrib/slog"
 	_ "github.com/joho/godotenv/autoload"
 )
 
@@ -32,6 +33,7 @@ const (
 
 type EnvConfigSchema struct {
 	AppEnv             string     `env:"APP_ENV"`
+	LogLevel           string     `env:"LOG_LEVEL"`
 	AppURL             string     `env:"APP_URL"`
 	DbProvider         DbProvider `env:"DB_PROVIDER"`
 	DbConnectionString string     `env:"DB_CONNECTION_STRING" options:"file"`
@@ -70,6 +72,7 @@ func init() {
 func defaultConfig() EnvConfigSchema {
 	return EnvConfigSchema{
 		AppEnv:             "production",
+		LogLevel:           "info",
 		DbProvider:         "sqlite",
 		DbConnectionString: "",
 		UploadPath:         "data/uploads",
@@ -115,6 +118,11 @@ func parseEnvConfig() error {
 	}
 
 	// Validate the environment variables
+	EnvConfig.LogLevel = strings.ToLower(EnvConfig.LogLevel)
+	if _, err := sloggin.ParseLevel(EnvConfig.LogLevel); err != nil {
+		return errors.New("invalid LOG_LEVEL value. Must be 'debug', 'info', 'warn' or 'error'")
+	}
+
 	switch EnvConfig.DbProvider {
 	case DbProviderSqlite:
 		if EnvConfig.DbConnectionString == "" {