# PlacementConstraintProperty

An object representing a constraint on task placement.

To learn more, see [Task Placement Constraints](https://docs.aws.amazon.com/AmazonECS/latest/developerguide/task-placement-constraints.html) in the Amazon Elastic Container Service Developer Guide.

- Source: Generated code
- Type last changed: v2.93.0 · 23 Aug 2023

## Example

```ts
// The code below shows an example of how to instantiate this type.
// The values are placeholders you should change.
import { aws_pipes as pipes } from 'aws-cdk-lib';
const placementConstraintProperty: pipes.CfnPipe.PlacementConstraintProperty = {
  expression: 'expression',
  type: 'type',
};
```

## Properties

- `expression`: string — A cluster query language expression to apply to the constraint.

  You cannot specify an expression if the constraint type is `distinctInstance` . To learn more, see [Cluster Query Language](https://docs.aws.amazon.com/AmazonECS/latest/developerguide/cluster-query-language.html) in the Amazon Elastic Container Service Developer Guide.

- `type`: string — The type of constraint.

  Use distinctInstance to ensure that each task in a particular group is running on a different container instance. Use memberOf to restrict the selection to a group of valid candidates.