Show offers in dstack apply for elastic container fleets

src/dstack/_internal/server/services/fleets.py

@@ -442,13 +442,25 @@ async def get_plan(
 
     offers = []
     if effective_spec.configuration.ssh_config is None:
-        offers_with_backends = await get_create_instance_offers(
-            project=project,
-            profile=effective_spec.merged_profile,
-            requirements=get_fleet_requirements(effective_spec),
-            fleet_spec=effective_spec,
-            blocks=effective_spec.configuration.blocks,
-        )
+        requirements = get_fleet_requirements(effective_spec)
+        if _is_elastic_cloud_fleet_spec(effective_spec):
+            offers_with_backends = await offers_services.get_offers_by_requirements(
+                project=project,
+                profile=effective_spec.merged_profile,
+                requirements=requirements,
+                multinode=(
+                    effective_spec.configuration.placement == InstanceGroupPlacement.CLUSTER
+                ),
+                blocks=effective_spec.configuration.blocks,
+            )
+        else:
+            offers_with_backends = await get_create_instance_offers(
+                project=project,
+                profile=effective_spec.merged_profile,
+                requirements=requirements,
+                fleet_spec=effective_spec,
+                blocks=effective_spec.configuration.blocks,
+            )
         offers = [offer for _, offer in offers_with_backends]
 
     _remove_fleet_spec_sensitive_info(effective_spec)
@@ -468,6 +480,16 @@ async def get_plan(
     return plan
 
 
+def _is_elastic_cloud_fleet_spec(fleet_spec: FleetSpec) -> bool:
+    nodes = fleet_spec.configuration.nodes
+    return (
+        fleet_spec.configuration.ssh_config is None
+        and nodes is not None
+        and nodes.min == 0
+        and nodes.target == 0
+    )
+
+
 async def get_create_instance_offers(
     project: ProjectModel,
     profile: Profile,

src/tests/_internal/server/routers/test_fleets.py

@@ -14,6 +14,7 @@
 from dstack._internal.core.models.common import EntityReference
 from dstack._internal.core.models.fleets import (
     FleetConfiguration,
+    FleetNodesSpec,
     FleetStatus,
     InstanceGroupPlacement,
     SSHHostParams,
@@ -2028,6 +2029,78 @@ async def test_returns_create_plan_for_new_fleet(
             "action": "create",
         }
 
+    @pytest.mark.asyncio
+    @pytest.mark.parametrize("test_db", ["sqlite", "postgres"], indirect=True)
+    async def test_returns_offers_for_elastic_container_backend_fleet(
+        self, test_db, session: AsyncSession, client: AsyncClient
+    ):
+        user = await create_user(session=session, global_role=GlobalRole.USER)
+        project = await create_project(session=session, owner=user)
+        await add_project_member(
+            session=session, project=project, user=user, project_role=ProjectRole.USER
+        )
+        offer = get_instance_offer_with_availability(
+            backend=BackendType.RUNPOD,
+            region="US-OR-1",
+            price=0.7185,
+        )
+        spec = get_fleet_spec(
+            conf=get_fleet_configuration(nodes=FleetNodesSpec(min=0, target=0, max=1))
+        )
+        with patch("dstack._internal.server.services.backends.get_project_backends") as m:
+            backend_mock = Mock()
+            m.return_value = [backend_mock]
+            backend_mock.TYPE = BackendType.RUNPOD
+            backend_mock.compute.return_value.get_offers.return_value = [offer]
+            response = await client.post(
+                f"/api/project/{project.name}/fleets/get_plan",
+                headers=get_auth_headers(user.token),
+                json={"spec": spec.dict()},
+            )
+            backend_mock.compute.return_value.get_offers.assert_called_once()
+
+        response_json = response.json()
+        assert response.status_code == 200, response_json
+        assert response_json["offers"] == [json.loads(offer.json())]
+        assert response_json["total_offers"] == 1
+        assert response_json["max_offer_price"] == offer.price
+
+    @pytest.mark.asyncio
+    @pytest.mark.parametrize("test_db", ["sqlite", "postgres"], indirect=True)
+    async def test_returns_no_offers_for_non_elastic_container_backend_fleet(
+        self, test_db, session: AsyncSession, client: AsyncClient
+    ):
+        user = await create_user(session=session, global_role=GlobalRole.USER)
+        project = await create_project(session=session, owner=user)
+        await add_project_member(
+            session=session, project=project, user=user, project_role=ProjectRole.USER
+        )
+        offer = get_instance_offer_with_availability(
+            backend=BackendType.RUNPOD,
+            region="US-OR-1",
+            price=0.7185,
+        )
+        spec = get_fleet_spec(
+            conf=get_fleet_configuration(nodes=FleetNodesSpec(min=0, target=1, max=1))
+        )
+        with patch("dstack._internal.server.services.backends.get_project_backends") as m:
+            backend_mock = Mock()
+            m.return_value = [backend_mock]
+            backend_mock.TYPE = BackendType.RUNPOD
+            backend_mock.compute.return_value.get_offers.return_value = [offer]
+            response = await client.post(
+                f"/api/project/{project.name}/fleets/get_plan",
+                headers=get_auth_headers(user.token),
+                json={"spec": spec.dict()},
+            )
+            backend_mock.compute.return_value.get_offers.assert_called_once()
+
+        response_json = response.json()
+        assert response.status_code == 200, response_json
+        assert response_json["offers"] == []
+        assert response_json["total_offers"] == 0
+        assert response_json["max_offer_price"] is None
+
     @pytest.mark.asyncio
     @pytest.mark.parametrize("test_db", ["sqlite", "postgres"], indirect=True)
     async def test_returns_update_plan_for_existing_fleet(