Sort web stack last in bulk operations to prevent self-restart interruption (#140)

CLAUDE.md

@@ -110,6 +110,10 @@ Browser tests are marked with `@pytest.mark.browser`. They use Playwright to tes
 Use `gh release create` to create releases. The tag is created automatically.
 
 ```bash
+# IMPORTANT: Ensure you're on latest origin/main before releasing!
+git fetch origin
+git checkout origin/main
+
 # Check current version
 git tag --sort=-v:refname | head -1
 

src/compose_farm/cli/common.py

@@ -4,6 +4,7 @@ from __future__ import annotations
 
 import asyncio
 import contextlib
+import os
 from pathlib import Path
 from typing import TYPE_CHECKING, Annotated, TypeVar
 
@@ -68,6 +69,21 @@ ServiceOption = Annotated[
 _MISSING_PATH_PREVIEW_LIMIT = 2
 _STATS_PREVIEW_LIMIT = 3  # Max number of pending migrations to show by name
 
+# Environment variable to identify the web stack (for self-update ordering)
+CF_WEB_STACK = os.environ.get("CF_WEB_STACK", "")
+
+
+def sort_web_stack_last(stacks: list[str]) -> list[str]:
+    """Move the web stack to the end of the list.
+
+    When updating all stacks, the web UI stack (compose-farm) should be updated
+    last. Otherwise, the container restarts mid-process and cancels remaining
+    updates. The CF_WEB_STACK env var identifies the web stack.
+    """
+    if CF_WEB_STACK and CF_WEB_STACK in stacks:
+        return [s for s in stacks if s != CF_WEB_STACK] + [CF_WEB_STACK]
+    return stacks
+
 
 def format_host(host: str | list[str]) -> str:
     """Format a host value for display."""

src/compose_farm/cli/lifecycle.py

@@ -23,6 +23,7 @@ from compose_farm.cli.common import (
     maybe_regenerate_traefik,
     report_results,
     run_async,
+    sort_web_stack_last,
     validate_host_for_stack,
     validate_stacks,
 )
@@ -171,6 +172,8 @@ def restart(
         raw = True
         results = run_async(run_on_stacks(cfg, stack_list, f"restart {service}", raw=raw))
     else:
+        # Sort web stack last to avoid self-restart canceling remaining restarts
+        stack_list = sort_web_stack_last(stack_list)
         raw = len(stack_list) == 1
         results = run_async(run_sequential_on_stacks(cfg, stack_list, ["down", "up -d"], raw=raw))
     maybe_regenerate_traefik(cfg, results)
@@ -206,6 +209,8 @@ def update(
             )
         )
     else:
+        # Sort web stack last to avoid self-restart canceling remaining updates
+        stack_list = sort_web_stack_last(stack_list)
         raw = len(stack_list) == 1
         results = run_async(
             run_sequential_on_stacks(
@@ -328,6 +333,11 @@ def apply(  # noqa: C901, PLR0912, PLR0915 (multi-phase reconciliation needs the
         console.print(f"\n{MSG_DRY_RUN}")
         return
 
+    # Sort web stack last in each phase to avoid self-restart canceling remaining work
+    migrations = sort_web_stack_last(migrations)
+    missing = sort_web_stack_last(missing)
+    to_refresh = sort_web_stack_last(to_refresh)
+
     # Execute changes
     console.print()
     all_results = []

tests/test_cli_lifecycle.py

@@ -437,3 +437,71 @@ class TestDownOrphaned:
             )
 
         assert exc_info.value.exit_code == 1
+
+
+class TestSortWebStackLast:
+    """Tests for the sort_web_stack_last helper."""
+
+    def test_no_web_stack_env(self) -> None:
+        """When CF_WEB_STACK is not set, list is unchanged."""
+        from compose_farm.cli import common
+
+        original = common.CF_WEB_STACK
+        try:
+            common.CF_WEB_STACK = ""
+            stacks = ["a", "b", "c"]
+            result = common.sort_web_stack_last(stacks)
+            assert result == ["a", "b", "c"]
+        finally:
+            common.CF_WEB_STACK = original
+
+    def test_web_stack_not_in_list(self) -> None:
+        """When web stack is not in list, list is unchanged."""
+        from compose_farm.cli import common
+
+        original = common.CF_WEB_STACK
+        try:
+            common.CF_WEB_STACK = "webstack"
+            stacks = ["a", "b", "c"]
+            result = common.sort_web_stack_last(stacks)
+            assert result == ["a", "b", "c"]
+        finally:
+            common.CF_WEB_STACK = original
+
+    def test_web_stack_moved_to_end(self) -> None:
+        """When web stack is in list, it's moved to the end."""
+        from compose_farm.cli import common
+
+        original = common.CF_WEB_STACK
+        try:
+            common.CF_WEB_STACK = "webstack"
+            stacks = ["a", "webstack", "b", "c"]
+            result = common.sort_web_stack_last(stacks)
+            assert result == ["a", "b", "c", "webstack"]
+        finally:
+            common.CF_WEB_STACK = original
+
+    def test_web_stack_already_last(self) -> None:
+        """When web stack is already last, list is unchanged."""
+        from compose_farm.cli import common
+
+        original = common.CF_WEB_STACK
+        try:
+            common.CF_WEB_STACK = "webstack"
+            stacks = ["a", "b", "webstack"]
+            result = common.sort_web_stack_last(stacks)
+            assert result == ["a", "b", "webstack"]
+        finally:
+            common.CF_WEB_STACK = original
+
+    def test_empty_list(self) -> None:
+        """Empty list returns empty list."""
+        from compose_farm.cli import common
+
+        original = common.CF_WEB_STACK
+        try:
+            common.CF_WEB_STACK = "webstack"
+            result = common.sort_web_stack_last([])
+            assert result == []
+        finally:
+            common.CF_WEB_STACK = original