Fix googledrive support for _FILE credentials

docs/reference/index.md

@@ -389,12 +389,19 @@ The values for each key currently match its default.
 ########### GOOGLE DRIVE STORAGE
 
 # The JSON credentials for a Google service account with access to Google Drive.
-# The value should be the path to a json file you mounted into the container.
+# You can provide either:
+# 1. The actual JSON content directly
+# 2. Use the _FILE suffix to load from a file (e.g., GOOGLE_DRIVE_CREDENTIALS_JSON_FILE)
 #
-# Example:
+# Examples:
+# Option 1 - JSON content:
+# docker run [...] \
+#    -e GOOGLE_DRIVE_CREDENTIALS_JSON='{"type":"service_account",...}'
+#
+# Option 2 - Using _FILE suffix (recommended for Docker Secrets):
 # docker run [...] \
 #    -v ./credentials.json:/creds/google-credentials.json \
-#    -e GOOGLE_DRIVE_CREDENTIALS_JSON=/creds/google-credentials.json
+#    -e GOOGLE_DRIVE_CREDENTIALS_JSON_FILE=/creds/google-credentials.json
 #
 # GOOGLE_DRIVE_CREDENTIALS_JSON=""
 

internal/storage/googledrive/googledrive.go

@@ -38,11 +38,10 @@ type Config struct {
 // NewStorageBackend creates and initializes a new Google Drive storage backend.
 func NewStorageBackend(opts Config, logFunc storage.Log) (storage.Backend, error) {
 	ctx := context.Background()
-	b, err := os.ReadFile(opts.CredentialsJSON)
-	if err != nil {
-		return nil, errwrap.Wrap(err, "unable to read credentials")
-	}
-	config, err := google.JWTConfigFromJSON(b, drive.DriveScope)
+
+	credentialsBytes := []byte(opts.CredentialsJSON)
+
+	config, err := google.JWTConfigFromJSON(credentialsBytes, drive.DriveScope)
 	if err != nil {
 		return nil, errwrap.Wrap(err, "unable to parse credentials")
 	}

test/googledrive/docker-compose.yml

@@ -35,7 +35,7 @@ services:
       BACKUP_PRUNING_PREFIX: test
       GOOGLE_DRIVE_ENDPOINT: http://openapi_mock:8080
       GOOGLE_DRIVE_TOKEN_URL: http://oauth2_mock:8090/issuer1/token
-      GOOGLE_DRIVE_CREDENTIALS_JSON: /etc/gdrive/credentials.json
+      GOOGLE_DRIVE_CREDENTIALS_JSON_FILE: /etc/gdrive/credentials.json
       GOOGLE_DRIVE_FOLDER_ID: "root"
     volumes:
       - app_data:/backup/app_data:ro