allow to override most of the "serve" flags from env files

Signed-off-by: Nicola Murino <nicola.murino@gmail.com>

internal/cmd/serve.go

@@ -16,13 +16,21 @@ package cmd
 
 import (
 	"os"
+	"path/filepath"
+	"strconv"
+	"strings"
 
 	"github.com/spf13/cobra"
+	"github.com/subosito/gotenv"
 
 	"github.com/drakkan/sftpgo/v2/internal/service"
 	"github.com/drakkan/sftpgo/v2/internal/util"
 )
 
+const (
+	envFileMaxSize = 1048576
+)
+
 var (
 	serveCmd = &cobra.Command{
 		Use:   "serve",
@@ -34,9 +42,11 @@ $ sftpgo serve
 
 Please take a look at the usage below to customize the startup options`,
 		Run: func(_ *cobra.Command, _ []string) {
+			configDir := util.CleanDirInput(configDir)
+			checkServeParamsFromEnvFiles(configDir)
 			service.SetGraceTime(graceTime)
 			service := service.Service{
-				ConfigDir:         util.CleanDirInput(configDir),
+				ConfigDir:         configDir,
 				ConfigFile:        configFile,
 				LogFilePath:       logFilePath,
 				LogMaxSize:        logMaxSize,
@@ -62,6 +72,75 @@ Please take a look at the usage below to customize the startup options`,
 	}
 )
 
+func setIntFromEnv(receiver *int, val string) {
+	converted, err := strconv.Atoi(val)
+	if err == nil {
+		*receiver = converted
+	}
+}
+
+func setBoolFromEnv(receiver *bool, val string) {
+	converted, err := strconv.ParseBool(strings.TrimSpace(val))
+	if err == nil {
+		*receiver = converted
+	}
+}
+
+func checkServeParamsFromEnvFiles(configDir string) { //nolint:gocyclo
+	// The logger is not yet initialized here, we have no way to report errors.
+	envd := filepath.Join(configDir, "env.d")
+	entries, err := os.ReadDir(envd)
+	if err != nil {
+		return
+	}
+	for _, entry := range entries {
+		info, err := entry.Info()
+		if err == nil && info.Mode().IsRegular() {
+			envFile := filepath.Join(envd, entry.Name())
+			if info.Size() > envFileMaxSize {
+				continue
+			}
+			envVars, err := gotenv.Read(envFile)
+			if err != nil {
+				return
+			}
+			for k, v := range envVars {
+				if _, isSet := os.LookupEnv(k); isSet {
+					continue
+				}
+				switch k {
+				case "SFTPGO_LOG_FILE_PATH":
+					logFilePath = v
+				case "SFTPGO_LOG_MAX_SIZE":
+					setIntFromEnv(&logMaxSize, v)
+				case "SFTPGO_LOG_MAX_BACKUPS":
+					setIntFromEnv(&logMaxBackups, v)
+				case "SFTPGO_LOG_MAX_AGE":
+					setIntFromEnv(&logMaxAge, v)
+				case "SFTPGO_LOG_COMPRESS":
+					setBoolFromEnv(&logCompress, v)
+				case "SFTPGO_LOG_LEVEL":
+					logLevel = v
+				case "SFTPGO_LOG_UTC_TIME":
+					setBoolFromEnv(&logUTCTime, v)
+				case "SFTPGO_CONFIG_FILE":
+					configFile = v
+				case "SFTPGO_LOADDATA_FROM":
+					loadDataFrom = v
+				case "SFTPGO_LOADDATA_MODE":
+					setIntFromEnv(&loadDataMode, v)
+				case "SFTPGO_LOADDATA_CLEAN":
+					setBoolFromEnv(&loadDataClean, v)
+				case "SFTPGO_LOADDATA_QUOTA_SCAN":
+					setIntFromEnv(&loadDataQuotaScan, v)
+				case "SFTPGO_GRACE_TIME":
+					setIntFromEnv(&graceTime, v)
+				}
+			}
+		}
+	}
+}
+
 func init() {
 	rootCmd.AddCommand(serveCmd)
 	addServeFlags(serveCmd)