feat(env): clean env variable values

- Remove surrounding spaces
- Remove suffix new line characters

internal/configuration/sources/secrets/helpers.go

@@ -2,13 +2,24 @@ package secrets
 
 import (
 	"os"
+	"strings"
 
 	"github.com/qdm12/gluetun/internal/configuration/sources/files"
 )
 
+// getCleanedEnv returns an environment variable value with
+// surrounding spaces and trailing new line characters removed.
+func getCleanedEnv(envKey string) (value string) {
+	value = os.Getenv(envKey)
+	value = strings.TrimSpace(value)
+	value = strings.TrimSuffix(value, "\r\n")
+	value = strings.TrimSuffix(value, "\n")
+	return value
+}
+
 func readSecretFileAsStringPtr(secretPathEnvKey, defaultSecretPath string) (
 	stringPtr *string, err error) {
-	path := os.Getenv(secretPathEnvKey)
+	path := getCleanedEnv(secretPathEnvKey)
 	if path == "" {
 		path = defaultSecretPath
 	}
@@ -17,7 +28,7 @@ func readSecretFileAsStringPtr(secretPathEnvKey, defaultSecretPath string) (
 
 func readSecretFileAsString(secretPathEnvKey, defaultSecretPath string) (
 	s string, err error) {
-	path := os.Getenv(secretPathEnvKey)
+	path := getCleanedEnv(secretPathEnvKey)
 	if path == "" {
 		path = defaultSecretPath
 	}