quit if downgrading or same verison.

provide a flag to force downgrade

Author: Zhao Wang

brainframe/cli/commands/update.py

@@ -1,4 +1,5 @@
 from argparse import ArgumentParser
+from packaging import version
 
 import i18n
 
@@ -16,6 +17,12 @@ def update():
 
     _, _, upgrade_version = docker_compose.check_download_version()
     existing_version = docker_compose.check_existing_version(install_path)
+    if version.parse(existing_version) >= version.parse(upgrade_version):
+        if not args.downgrade:
+            print_utils.fail_translate("update.version-failing",
+                                       existing_version=existing_version,
+                                       upgrade_version=upgrade_version)
+
     print_utils.translate("update.upgrade-version",
                           existing_version=existing_version,
                           upgrade_version=upgrade_version)
@@ -60,4 +67,10 @@ def _parse_args():
         "--restart", action="store_true", help=i18n.t("update.restart-help")
     )
 
+    parser.add_argument(
+        "--downgrade",
+        action="store_true",
+        help=i18n.t("update.downgrade-help"),
+    )
+
     return subcommand_parse_args(parser)

brainframe/cli/translations/update.en.yml

@@ -6,8 +6,14 @@ en:
   supported, and may result in instability or data loss."
   restart-help: "If provided, the server will restart after the update is
   complete"
+  downgrade-help: "If provided, BrainFrame server will be forced to downgrade."
   ask-restart: "Would you like to restart the BrainFrame server to apply the
   update?"
   complete: "BrainFrame has been updated!"
   upgrade-version: "BrainFrame:%{existing_version} detected under your installation
   location, we will replace it with BrainFrame:%{upgrade_version}"
+  version-failing: "You have BrainFrame:%{existing_version} installed already.
+  The latest version we found on updating server is
+  BrainFrame:%{upgrade_version}. We don't recommend downgrading BrainFrame
+  for stability reasons. This request will be ignored. But you can force to
+  downgrade by appending --downgrade flag."

poetry.lock

@@ -20,6 +20,7 @@ python = ">=3.6"
 python-i18n = "^0.3"
 pyyaml = "^5.3"
 distro = "^1.5"
+packaging = "^20.4"
 
 [tool.poetry.dev-dependencies]
 black = "^19.10b0"