Amazon ECS task metadata endpoint version 2 - Amazon Elastic Container Service
Enabling task metadataTask metadata endpoint pathsTask metadata JSON responseExample task metadata response

Amazon ECS task metadata endpoint version 2

Important

The task metadata version 2 endpoint is no longer being actively maintained. We recommend that you update the task metadata version 4 endpoint to get the latest metadata endpoint information. For more information, see Amazon ECS task metadata endpoint version 4.

Beginning with version 1.17.0 of the Amazon ECS container agent, various task metadata and Docker stats are available to tasks that use the awsvpc network mode at an HTTP endpoint that is provided by the Amazon ECS container agent.

All containers belonging to tasks that are launched with the awsvpc network mode receive a local IPv4 address within a predefined link-local address range. When a container queries the metadata endpoint, the Amazon ECS container agent can determine which task the container belongs to based on its unique IP address, and metadata and stats for that task are returned.

Enabling task metadata

The task metadata version 2 feature is enabled by default for the following:

  • Tasks using the Fargate launch type that use platform version v1.1.0 or later. For more information, see Fargate Linux platform versions.

  • Tasks using the EC2 launch type that also use the awsvpc network mode and are launched on Amazon EC2 Linux infrastructure running at least version 1.17.0 of the Amazon ECS container agent or on Amazon EC2 Windows infrastructure running at least version 1.54.0 of the Amazon ECS container agent. For more information, see Linux container instance management.

You can add support for this feature on older container instances by updating the agent to the latest version. For more information, see Updating the Amazon ECS container agent.

Task metadata endpoint paths

The following API endpoints are available to containers:

169.254.170.2/v2/metadata

This endpoint returns metadata JSON for the task, including a list of the container IDs and names for all of the containers associated with the task. For more information about the response for this endpoint, see Task metadata JSON response.

169.254.170.2/v2/metadata/<container-id>

This endpoint returns metadata JSON for the specified Docker container ID.

169.254.170.2/v2/metadata/taskWithTags

This path returns the metadata for the task included in the /task endpoint in addition to the task and container instance tags that can be retrieved using the ListTagsForResource API.

169.254.170.2/v2/stats

This endpoint returns Docker stats JSON for all of the containers associated with the task. For more information about each of the returned stats, see ContainerStats in the Docker API documentation.

169.254.170.2/v2/stats/<container-id>

This endpoint returns Docker stats JSON for the specified Docker container ID. For more information about each of the returned stats, see ContainerStats in the Docker API documentation.

Task metadata JSON response

The following information is returned from the task metadata endpoint (169.254.170.2/v2/metadata) JSON response.

Cluster

The Amazon Resource Name (ARN) or short name of the Amazon ECS cluster to which the task belongs.

TaskARN

The full Amazon Resource Name (ARN) of the task to which the container belongs.

Family

The family of the Amazon ECS task definition for the task.

Revision

The revision of the Amazon ECS task definition for the task.

DesiredStatus

The desired status for the task from Amazon ECS.

KnownStatus

The known status for the task from Amazon ECS.

Limits

The resource limits specified at the task level, such as CPU (expressed in vCPUs) and memory. This parameter is omitted if no resource limits are defined.

PullStartedAt

The timestamp for when the first container image pull began.

PullStoppedAt

The timestamp for when the last container image pull finished.

AvailabilityZone

The Availability Zone the task is in.

Note

The Availability Zone metadata is only available for Fargate tasks using platform version 1.4 or later (Linux) or 1.0.0 or later (Windows).

Containers

A list of container metadata for each container associated with the task.

DockerId

The Docker ID for the container.

Name

The name of the container as specified in the task definition.

DockerName

The name of the container supplied to Docker. The Amazon ECS container agent generates a unique name for the container to avoid name collisions when multiple copies of the same task definition are run on a single instance.

Image

The image for the container.

ImageID

The SHA-256 digest for the image.

Ports

Any ports exposed for the container. This parameter is omitted if there are no exposed ports.

Labels

Any labels applied to the container. This parameter is omitted if there are no labels applied.

DesiredStatus

The desired status for the container from Amazon ECS.

KnownStatus

The known status for the container from Amazon ECS.

ExitCode

The exit code for the container. This parameter is omitted if the container has not exited.

Limits

The resource limits specified at the container level, such as CPU (expressed in CPU units) and memory. This parameter is omitted if no resource limits are defined.

CreatedAt

The time stamp for when the container was created. This parameter is omitted if the container has not been created yet.

StartedAt

The time stamp for when the container started. This parameter is omitted if the container has not started yet.

FinishedAt

The time stamp for when the container stopped. This parameter is omitted if the container has not stopped yet.

Type

The type of the container. Containers that are specified in your task definition are of type NORMAL. You can ignore other container types, which are used for internal task resource provisioning by the Amazon ECS container agent.

Networks

The network information for the container, such as the network mode and IP address. This parameter is omitted if no network information is defined.

ClockDrift

The information about the difference between the reference time and the system time. This applies to the Linux operating system. This capability uses Amazon Time Sync Service to measure clock accuracy and provide the clock error bound for containers. For more information, see Set the time for your Linux instance in the Amazon EC2 User Guide for Linux instances.

ReferenceTime

The basis of clock accuracy. Amazon ECS uses the Coordinated Universal Time (UTC) global standard through NTP, for example 2021-09-07T16:57:44Z.

ClockErrorBound

The measure of clock error, defined as the offset to UTC. This error is the difference in milliseconds between the reference time and the system time.

ClockSynchronizationStatus

Indicates whether the most recent synchronization attempt between the system time and the reference time was successful.

The valid values are SYNCHRONIZED and NOT_SYNCHRONIZED.

ExecutionStoppedAt

The time stamp for when the tasks DesiredStatus moved to STOPPED. This occurs when an essential container moves to STOPPED.

Example task metadata response

The following JSON response is for a single-container task.

{
  "Cluster": "default",
  "TaskARN": "arn:aws:ecs:us-east-2:012345678910:task/9781c248-0edd-4cdb-9a93-f63cb662a5d3",
  "Family": "nginx",
  "Revision": "5",
  "DesiredStatus": "RUNNING",
  "KnownStatus": "RUNNING",
  "Containers": [
    {
      "DockerId": "731a0d6a3b4210e2448339bc7015aaa79bfe4fa256384f4102db86ef94cbbc4c",
      "Name": "~internal~ecs~pause",
      "DockerName": "ecs-nginx-5-internalecspause-acc699c0cbf2d6d11700",
      "Image": "amazon/amazon-ecs-pause:0.1.0",
      "ImageID": "",
      "Labels": {
        "com.amazonaws.ecs.cluster": "default",
        "com.amazonaws.ecs.container-name": "~internal~ecs~pause",
        "com.amazonaws.ecs.task-arn": "arn:aws:ecs:us-east-2:012345678910:task/9781c248-0edd-4cdb-9a93-f63cb662a5d3",
        "com.amazonaws.ecs.task-definition-family": "nginx",
        "com.amazonaws.ecs.task-definition-version": "5"
      },
      "DesiredStatus": "RESOURCES_PROVISIONED",
      "KnownStatus": "RESOURCES_PROVISIONED",
      "Limits": {
        "CPU": 0,
        "Memory": 0
      },
      "CreatedAt": "2018-02-01T20:55:08.366329616Z",
      "StartedAt": "2018-02-01T20:55:09.058354915Z",
      "Type": "CNI_PAUSE",
      "Networks": [
        {
          "NetworkMode": "awsvpc",
          "IPv4Addresses": [
            "10.0.2.106"
          ]
        }
      ]
    },
    {
      "DockerId": "43481a6ce4842eec8fe72fc28500c6b52edcc0917f105b83379f88cac1ff3946",
      "Name": "nginx-curl",
      "DockerName": "ecs-nginx-5-nginx-curl-ccccb9f49db0dfe0d901",
      "Image": "nrdlngr/nginx-curl",
      "ImageID": "sha256:2e00ae64383cfc865ba0a2ba37f61b50a120d2d9378559dcd458dc0de47bc165",
      "Labels": {
        "com.amazonaws.ecs.cluster": "default",
        "com.amazonaws.ecs.container-name": "nginx-curl",
        "com.amazonaws.ecs.task-arn": "arn:aws:ecs:us-east-2:012345678910:task/9781c248-0edd-4cdb-9a93-f63cb662a5d3",
        "com.amazonaws.ecs.task-definition-family": "nginx",
        "com.amazonaws.ecs.task-definition-version": "5"
      },
      "DesiredStatus": "RUNNING",
      "KnownStatus": "RUNNING",
      "Limits": {
        "CPU": 512,
        "Memory": 512
      },
      "CreatedAt": "2018-02-01T20:55:10.554941919Z",
      "StartedAt": "2018-02-01T20:55:11.064236631Z",
      "Type": "NORMAL",
      "Networks": [
        {
          "NetworkMode": "awsvpc",
          "IPv4Addresses": [
            "10.0.2.106"
          ]
        }
      ]
    }
  ],
  "PullStartedAt": "2018-02-01T20:55:09.372495529Z",
  "PullStoppedAt": "2018-02-01T20:55:10.552018345Z",
  "AvailabilityZone": "us-east-2b"
}