FEATURE: warn the user when there is not enough space on disk to upload a backup

app/controllers/admin/backups_controller.rb

@@ -101,13 +101,15 @@ class Admin::BackupsController < Admin::AdminController
 
   def upload_chunk
     filename   = params.fetch(:resumableFilename)
-    return render nothing:true, status: 415 unless filename.to_s.end_with?(".tar.gz")
+    total_size = params.fetch(:resumableTotalSize).to_i
+
+    return render status: 415, text: I18n.t("backup.backup_file_should_be_tar_gz") unless filename.to_s.end_with?(".tar.gz")
+    return render status: 415, text: I18n.t("backup.not_enough_space_on_disk")     unless has_enough_space_on_disk?(total_size)
 
     file               = params.fetch(:file)
     identifier         = params.fetch(:resumableIdentifier)
     chunk_number       = params.fetch(:resumableChunkNumber).to_i
     chunk_size         = params.fetch(:resumableChunkSize).to_i
-    total_size         = params.fetch(:resumableTotalSize).to_i
     current_chunk_size = params.fetch(:resumableCurrentChunkSize).to_i
 
     # path to chunk file
@@ -130,4 +132,10 @@ class Admin::BackupsController < Admin::AdminController
     render nothing: true
   end
 
+  private
+
+  def has_enough_space_on_disk?(size)
+    `df -l . | tail -1 | tr -s ' ' | cut -d ' ' -f 4`.to_i > size
+  end
+
 end

config/locales/client.en.yml

@@ -1345,7 +1345,7 @@ en:
           text: "UPLOAD"
           uploading: "UPLOADING"
           success: "'{{filename}}' has successfully been uploaded."
-          error: "There has been an error ({{message}}) while uploading '{{filename}}'"
+          error: "There has been an error while uploading '{{filename}}': {{message}}"
         operations:
           is_running: "An operation is currently running..."
           failed: "The {{operation}} failed. Please check the logs."

config/locales/server.en.yml

@@ -27,6 +27,8 @@ en:
 
   backup:
     operation_already_running: "An operation is currently running. Can't start a new job right now."
+    backup_file_should_be_tar_gz: "The backup file should be a .tar.gz archive."
+    not_enough_space_on_disk: "There is not enough space on disk to upload this backup."
 
   read_only_mode_enabled: "The site is in read only mode. Interactions are disabled."