Render fleet spec diff in CLI

r4victor · r4victor · commit a0839d4cab4f · 2026-04-13T14:32:39.000+05:00
diff --git a/src/dstack/_internal/cli/services/configurators/fleet.py b/src/dstack/_internal/cli/services/configurators/fleet.py
@@ -34,9 +34,10 @@
     InstanceGroupPlacement,
 )
 from dstack._internal.core.models.instances import InstanceStatus, SSHKey
-from dstack._internal.core.services.diff import diff_models
+from dstack._internal.core.services.diff import copy_model, diff_models
 from dstack._internal.utils.common import local_time
 from dstack._internal.utils.logging import get_logger
+from dstack._internal.utils.nested_list import NestedList, NestedListItem
 from dstack._internal.utils.ssh import convert_ssh_key_to_pem, generate_public_key, pkey_from_str
 from dstack.api.utils import load_profile
 
@@ -85,14 +86,10 @@ def _apply_plan(self, plan: FleetPlan, command_args: argparse.Namespace):
                 )
             confirm_message += "Create the fleet?"
         else:
+            effective_spec = plan.get_effective_spec()
+            diff = _render_fleet_spec_diff(plan.current_resource.spec, effective_spec)
             action_message += f"Found fleet [code]{plan.spec.configuration.name}[/]."
-            if plan.action == ApplyAction.CREATE:
-                delete_fleet_name = plan.current_resource.name
-                action_message += (
-                    " Configuration changes detected. Cannot update the fleet in-place"
-                )
-                confirm_message += "Re-create the fleet?"
-            elif plan.current_resource.spec == plan.effective_spec:
+            if plan.current_resource.spec == effective_spec:
                 if command_args.yes and not command_args.force:
                     # --force is required only with --yes,
                     # otherwise we may ask for force apply interactively.
@@ -103,8 +100,26 @@ def _apply_plan(self, plan: FleetPlan, command_args: argparse.Namespace):
                 delete_fleet_name = plan.current_resource.name
                 action_message += " No configuration changes detected."
                 confirm_message += "Re-create the fleet?"
+            elif plan.action == ApplyAction.CREATE:
+                delete_fleet_name = plan.current_resource.name
+                if diff is not None:
+                    # TODO: Highlight only the fields that block in-place update instead of
+                    # showing the full detected diff here.
+                    action_message += (
+                        f" Detected changes that [error]cannot[/] be updated in-place:\n{diff}"
+                    )
+                else:
+                    action_message += (
+                        " Configuration changes detected. Cannot update the fleet in-place."
+                    )
+                confirm_message += "Re-create the fleet?"
             else:
-                action_message += " Configuration changes detected."
+                if diff is not None:
+                    action_message += (
+                        f" Detected changes that [code]can[/] be updated in-place:\n{diff}"
+                    )
+                else:
+                    action_message += " Configuration changes detected."
                 confirm_message += "Update the fleet in-place?"
 
         console.print(action_message)
@@ -357,6 +372,44 @@ def _resolve_ssh_key(ssh_key_path: Optional[str]) -> Optional[SSHKey]:
         exit()
 
 
+def _render_fleet_spec_diff(old_spec: FleetSpec, new_spec: FleetSpec) -> Optional[str]:
+    old_spec = copy_model(old_spec)
+    new_spec = copy_model(new_spec)
+    changed_spec_fields = list(diff_models(old_spec, new_spec))
+    if not changed_spec_fields:
+        return None
+
+    nested_list = NestedList()
+    for spec_field in changed_spec_fields:
+        if spec_field == "merged_profile":
+            continue
+        if spec_field == "configuration":
+            item = NestedListItem(
+                "Configuration properties:",
+                children=[
+                    NestedListItem(field)
+                    for field in diff_models(old_spec.configuration, new_spec.configuration)
+                ],
+            )
+        elif spec_field == "profile":
+            item = NestedListItem(
+                "Profile properties:",
+                children=[
+                    NestedListItem(field)
+                    for field in diff_models(old_spec.profile, new_spec.profile)
+                ],
+            )
+        elif spec_field == "configuration_path":
+            item = NestedListItem("Configuration path")
+        else:
+            item = NestedListItem(spec_field.replace("_", " ").capitalize())
+        nested_list.children.append(item)
+
+    if not nested_list.children:
+        return None
+    return nested_list.render()
+
+
 def _print_plan_header(plan: FleetPlan):
     def th(s: str) -> str:
         return f"[bold]{s}[/bold]"
diff --git a/src/dstack/_internal/cli/services/configurators/run.py b/src/dstack/_internal/cli/services/configurators/run.py
@@ -152,6 +152,8 @@ def apply_configuration(
                 confirm_message = "Stop and override the run?"
             elif not run_plan.current_resource.status.is_finished():
                 stop_run_name = run_plan.current_resource.run_spec.run_name
+                # TODO: Highlight only the fields that block in-place update instead of
+                # showing the full detected diff here.
                 console.print(
                     f"Active run [code]{conf.name}[/] already exists."
                     f" Detected changes that [error]cannot[/] be updated in-place:\n{diff}"
diff --git a/src/tests/_internal/cli/services/configurators/test_fleet.py b/src/tests/_internal/cli/services/configurators/test_fleet.py
@@ -1,13 +1,129 @@
 import argparse
-from typing import List, Tuple
+from datetime import datetime, timezone
+from textwrap import dedent
+from typing import List, Optional, Tuple
 from unittest.mock import Mock
+from uuid import uuid4
 
 import pytest
+from rich.console import Console
 
-from dstack._internal.cli.services.configurators.fleet import FleetConfigurator
+import dstack._internal.cli.services.configurators.fleet as fleet_configurator_module
+from dstack._internal.cli.services.configurators.fleet import (
+    FleetConfigurator,
+    _render_fleet_spec_diff,
+)
 from dstack._internal.core.errors import ConfigurationError
+from dstack._internal.core.models.common import ApplyAction
 from dstack._internal.core.models.envs import Env
-from dstack._internal.core.models.fleets import FleetConfiguration
+from dstack._internal.core.models.fleets import (
+    Fleet,
+    FleetConfiguration,
+    FleetNodesSpec,
+    FleetPlan,
+    FleetSpec,
+    FleetStatus,
+    InstanceGroupPlacement,
+)
+from dstack._internal.core.models.profiles import Profile
+
+
+def create_conf() -> FleetConfiguration:
+    return FleetConfiguration.parse_obj({"ssh_config": {"hosts": ["1.2.3.4"]}})
+
+
+def apply_args(
+    conf: FleetConfiguration, args: List[str]
+) -> Tuple[FleetConfiguration, argparse.Namespace]:
+    parser = argparse.ArgumentParser()
+    configurator = FleetConfigurator(Mock())
+    configurator.register_args(parser)
+    conf = conf.copy(deep=True)
+    configurator_args = parser.parse_args(args)
+    configurator.apply_args(conf, configurator_args)
+    return conf, configurator_args
+
+
+def get_cloud_fleet_spec(
+    *,
+    name: str = "test-fleet",
+    nodes: Optional[FleetNodesSpec] = None,
+    placement: Optional[InstanceGroupPlacement] = None,
+) -> FleetSpec:
+    if nodes is None:
+        nodes = FleetNodesSpec(min=0, target=0, max=1)
+    return FleetSpec(
+        configuration=FleetConfiguration(
+            name=name,
+            nodes=nodes,
+            placement=placement,
+        ),
+        configuration_path="fleet.dstack.yml",
+        profile=Profile(),
+    )
+
+
+def get_ssh_fleet_spec(
+    *,
+    name: str = "test-fleet",
+    hosts: Optional[list[str]] = None,
+) -> FleetSpec:
+    if hosts is None:
+        hosts = ["10.0.0.100"]
+    return FleetSpec(
+        configuration=FleetConfiguration.parse_obj(
+            {
+                "name": name,
+                "ssh_config": {"hosts": hosts},
+            }
+        ),
+        configuration_path="fleet.dstack.yml",
+        profile=Profile(),
+    )
+
+
+def create_fleet_plan(
+    *,
+    current_spec: FleetSpec,
+    spec: FleetSpec,
+    action: ApplyAction,
+) -> FleetPlan:
+    return FleetPlan(
+        project_name="test-project",
+        user="test-user",
+        spec=spec,
+        effective_spec=spec,
+        current_resource=Fleet(
+            id=uuid4(),
+            name=current_spec.configuration.name or "test-fleet",
+            project_name="test-project",
+            spec=current_spec,
+            created_at=datetime.now(timezone.utc),
+            status=FleetStatus.ACTIVE,
+            instances=[],
+        ),
+        offers=[],
+        total_offers=0,
+        action=action,
+    )
+
+
+def get_command_args() -> argparse.Namespace:
+    return argparse.Namespace(
+        yes=False,
+        force=False,
+        detach=False,
+    )
+
+
+def patch_console_and_confirm(
+    monkeypatch: pytest.MonkeyPatch,
+) -> tuple[Console, Mock]:
+    console = Console(record=True, force_terminal=False, color_system=None, width=120)
+    confirm_ask = Mock(return_value=False)
+    monkeypatch.setattr(fleet_configurator_module, "console", console)
+    monkeypatch.setattr(fleet_configurator_module, "confirm_ask", confirm_ask)
+    return console, confirm_ask
 
 
 class TestFleetConfigurator:
@@ -39,17 +155,93 @@ def test_env_value_from_environ_not_set(self, monkeypatch: pytest.MonkeyPatch):
             apply_args(conf, ["--env", "FROM_ENV"])
 
 
-def create_conf() -> FleetConfiguration:
-    return FleetConfiguration.parse_obj({"ssh_config": {"hosts": ["1.2.3.4"]}})
+class TestApplyPlanMessages:
+    def test_prints_in_place_update_diff(self, monkeypatch: pytest.MonkeyPatch):
+        console, confirm_ask = patch_console_and_confirm(monkeypatch)
+        current_spec = get_cloud_fleet_spec(nodes=FleetNodesSpec(min=0, target=0, max=1))
+        spec = get_cloud_fleet_spec(nodes=FleetNodesSpec(min=1, target=1, max=1))
+        plan = create_fleet_plan(
+            current_spec=current_spec,
+            spec=spec,
+            action=ApplyAction.UPDATE,
+        )
 
+        FleetConfigurator(Mock())._apply_plan(plan, get_command_args())
 
-def apply_args(
-    conf: FleetConfiguration, args: List[str]
-) -> Tuple[FleetConfiguration, argparse.Namespace]:
-    parser = argparse.ArgumentParser()
-    configurator = FleetConfigurator(Mock())
-    configurator.register_args(parser)
-    conf = conf.copy(deep=True)
-    configurator_args = parser.parse_args(args)
-    configurator.apply_args(conf, configurator_args)
-    return conf, configurator_args
+        output = console.export_text()
+        assert "Found fleet test-fleet." in output
+        assert "Detected changes that can be updated in-place:" in output
+        assert "- Configuration properties:" in output
+        assert "  - nodes" in output
+        confirm_ask.assert_called_once_with("Update the fleet in-place?")
+
+    def test_prints_recreate_diff(self, monkeypatch: pytest.MonkeyPatch):
+        console, confirm_ask = patch_console_and_confirm(monkeypatch)
+        current_spec = get_cloud_fleet_spec(placement=InstanceGroupPlacement.ANY)
+        spec = get_cloud_fleet_spec(placement=InstanceGroupPlacement.CLUSTER)
+        plan = create_fleet_plan(
+            current_spec=current_spec,
+            spec=spec,
+            action=ApplyAction.CREATE,
+        )
+
+        FleetConfigurator(Mock())._apply_plan(plan, get_command_args())
+
+        output = console.export_text()
+        assert "Found fleet test-fleet." in output
+        assert "Detected changes that cannot be updated in-place:" in output
+        assert "- Configuration properties:" in output
+        assert "  - placement" in output
+        confirm_ask.assert_called_once_with("Re-create the fleet?")
+
+    def test_prints_no_diff_message(self, monkeypatch: pytest.MonkeyPatch):
+        console, confirm_ask = patch_console_and_confirm(monkeypatch)
+        spec = get_cloud_fleet_spec()
+        plan = create_fleet_plan(
+            current_spec=spec,
+            spec=spec.copy(deep=True),
+            action=ApplyAction.UPDATE,
+        )
+
+        FleetConfigurator(Mock())._apply_plan(plan, get_command_args())
+
+        output = console.export_text()
+        assert "Found fleet test-fleet." in output
+        assert "No configuration changes detected." in output
+        assert "Detected changes that" not in output
+        confirm_ask.assert_called_once_with("Re-create the fleet?")
+
+
+class TestRenderFleetSpecDiff:
+    def test_renders_cloud_nodes_change(self):
+        old = get_cloud_fleet_spec(nodes=FleetNodesSpec(min=0, target=0, max=1))
+        new = get_cloud_fleet_spec(nodes=FleetNodesSpec(min=1, target=1, max=1))
+
+        assert (
+            _render_fleet_spec_diff(old, new)
+            == dedent(
+                """
+                - Configuration properties:
+                  - nodes
+                """
+            ).lstrip()
+        )
+
+    def test_renders_ssh_hosts_change(self):
+        old = get_ssh_fleet_spec(hosts=["10.0.0.100"])
+        new = get_ssh_fleet_spec(hosts=["10.0.0.100", "10.0.0.101"])
+
+        assert (
+            _render_fleet_spec_diff(old, new)
+            == dedent(
+                """
+                - Configuration properties:
+                  - ssh_config
+                """
+            ).lstrip()
+        )
+
+    def test_no_diff(self):
+        spec = get_cloud_fleet_spec()
+
+        assert _render_fleet_spec_diff(spec, spec.copy(deep=True)) is None
