added test for partial capacity

Author: sanderegg

packages/aws-library/tests/test_ec2_client.py

@@ -731,3 +731,108 @@ async def mock_run_instances(*args, **kwargs):
 
     # Verify no instances were created
     await _assert_no_instances_in_ec2(ec2_client)
+
+
+async def test_launch_instances_partial_capacity_then_insufficient_capacity(
+    simcore_ec2_api: SimcoreEC2API,
+    ec2_client: EC2Client,
+    fake_ec2_instance_type: EC2InstanceType,
+    faker: Faker,
+    aws_subnet_id: str,
+    aws_security_group_id: str,
+    aws_ami_id: str,
+    mocker: MockerFixture,
+):
+    """Test that launch_instances handles partial capacity correctly.
+
+    First call: ask for 3 instances (min 1) -> should get 2, no error
+    Second call: ask for 3 instances (min 1) -> should raise EC2InsufficientCapacityError
+    """
+    await _assert_no_instances_in_ec2(ec2_client)
+
+    # Create a config with a single subnet (as requested)
+    ec2_instance_config = EC2InstanceConfig(
+        type=fake_ec2_instance_type,
+        tags=faker.pydict(allowed_types=(str,)),
+        startup_script=faker.pystr(),
+        ami_id=aws_ami_id,
+        key_name=faker.pystr(),
+        security_group_ids=[aws_security_group_id],
+        subnet_ids=[aws_subnet_id],  # Single subnet only
+        iam_instance_profile="",
+    )
+
+    # Mock the EC2 client to simulate partial capacity behavior
+    original_run_instances = simcore_ec2_api.client.run_instances
+    call_count = 0
+
+    async def mock_run_instances(*args, **kwargs):
+        nonlocal call_count
+        call_count += 1
+
+        if call_count == 1:
+            # First call: return only 2 instances when 3 were requested
+            # Simulate that the subnet has capacity for only 2 machines
+            kwargs_copy = kwargs.copy()
+            kwargs_copy["MinCount"] = 2
+            kwargs_copy["MaxCount"] = 2
+            return await original_run_instances(*args, **kwargs_copy)
+        else:
+            # Second call: simulate insufficient capacity (subnet is full)
+            error_response = {
+                "Error": {
+                    "Code": "InsufficientInstanceCapacity",
+                    "Message": "Insufficient capacity.",
+                }
+            }
+            raise botocore.exceptions.ClientError(error_response, "RunInstances")
+
+    # Apply the mock for the first call
+    with mocker.patch.object(
+        simcore_ec2_api.client, "run_instances", side_effect=mock_run_instances
+    ):
+        # First call: ask for 3 instances (min 1) -> should get 2, no error
+        instances = await simcore_ec2_api.launch_instances(
+            ec2_instance_config,
+            min_number_of_instances=1,
+            number_of_instances=3,
+        )
+
+        # Verify we got 2 instances (partial capacity)
+        assert len(instances) == 2
+        assert call_count == 1
+
+        # Verify instances were created
+        await _assert_instances_in_ec2(
+            ec2_client,
+            expected_num_reservations=1,
+            expected_num_instances=2,
+            expected_instance_type=ec2_instance_config.type,
+            expected_tags=ec2_instance_config.tags,
+            expected_state="running",
+        )
+
+        # Second call: ask for 3 instances (min 1) -> should raise EC2InsufficientCapacityError
+        with pytest.raises(EC2InsufficientCapacityError) as exc_info:
+            await simcore_ec2_api.launch_instances(
+                ec2_instance_config,
+                min_number_of_instances=1,
+                number_of_instances=3,
+            )
+
+        # Verify that run_instances was called twice total
+        assert call_count == 2
+
+        # Verify the error contains the expected information
+        assert hasattr(exc_info.value, "instance_type")
+        assert exc_info.value.instance_type == fake_ec2_instance_type.name
+
+        # Verify still only 2 instances exist (no new ones were created)
+        await _assert_instances_in_ec2(
+            ec2_client,
+            expected_num_reservations=1,
+            expected_num_instances=2,
+            expected_instance_type=ec2_instance_config.type,
+            expected_tags=ec2_instance_config.tags,
+            expected_state="running",
+        )