# HealthCheckProperty

The `HealthCheck` property specifies an object representing a container health check.

Health check parameters that are specified in a container definition override any Docker health checks that exist in the container image (such as those specified in a parent image or from the image's Dockerfile). This configuration maps to the `HEALTHCHECK` parameter of docker run.

> The Amazon ECS container agent only monitors and reports on the health checks specified in the task definition. Amazon ECS does not monitor Docker health checks that are embedded in a container image and not specified in the container definition. Health check parameters that are specified in a container definition override any Docker health checks that exist in the container image.

If a task is run manually, and not as part of a service, the task will continue its lifecycle regardless of its health status. For tasks that are part of a service, if the task reports as unhealthy then the task will be stopped and the service scheduler will replace it.

The following are notes about container health check support:

- Container health checks require version 1.17.0 or greater of the Amazon ECS container agent. For more information, see [Updating the Amazon ECS Container Agent](https://docs.aws.amazon.com/AmazonECS/latest/developerguide/ecs-agent-update.html) .
- Container health checks are supported for Fargate tasks if you are using platform version 1.1.0 or greater. For more information, see [AWS Fargate Platform Versions](https://docs.aws.amazon.com/AmazonECS/latest/developerguide/platform_versions.html) .
- Container health checks are not supported for tasks that are part of a service that is configured to use a Classic Load Balancer.

- 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_ecs as ecs } from 'aws-cdk-lib';
const healthCheckProperty: ecs.CfnTaskDefinition.HealthCheckProperty = {
  command: ['command'],
  interval: 123,
  retries: 123,
  startPeriod: 123,
  timeout: 123,
};
```

## Properties

- `command`: string[] — A string array representing the command that the container runs to determine if it is healthy.

  The string array must start with `CMD` to run the command arguments directly, or `CMD-SHELL` to run the command with the container's default shell.

  When you use the AWS Management Console JSON panel, the AWS Command Line Interface , or the APIs, enclose the list of commands in double quotes and brackets.

  `[ "CMD-SHELL", "curl -f http://localhost/ || exit 1" ]`

  You don't include the double quotes and brackets when you use the AWS Management Console.

  `CMD-SHELL, curl -f http://localhost/ || exit 1`

  An exit code of 0 indicates success, and non-zero exit code indicates failure. For more information, see `HealthCheck` in the docker container create command.

- `interval`: number — The time period in seconds between each health check execution.

  You may specify between 5 and 300 seconds. The default value is 30 seconds. This value applies only when you specify a `command` .

- `retries`: number — The number of times to retry a failed health check before the container is considered unhealthy.

  You may specify between 1 and 10 retries. The default value is 3. This value applies only when you specify a `command` .

- `startPeriod`: number — The optional grace period to provide containers time to bootstrap before failed health checks count towards the maximum number of retries.

  You can specify between 0 and 300 seconds. By default, the `startPeriod` is off. This value applies only when you specify a `command` .

  > If a health check succeeds within the `startPeriod` , then the container is considered healthy and any subsequent failures count toward the maximum number of retries.

- `timeout`: number — The time period in seconds to wait for a health check to succeed before it is considered a failure.

  You may specify between 2 and 60 seconds. The default value is 5. This value applies only when you specify a `command` .