Task metadata endpoint version 4

Important

If you are using Amazon ECS tasks hosted on Amazon EC2 instances, see Amazon ECS task metadata endpoint in the Amazon Elastic Container Service Developer Guide.

Beginning with Fargate platform version 1.4.0, an environment variable named ECS_CONTAINER_METADATA_URI_V4 is injected into each container in a task. When you query the task metadata endpoint version 4, various task metadata and Docker stats are available to tasks.

The task metadata endpoint version 4 functions like the version 3 endpoint but provides additional network metadata for your containers and tasks. Additional network metrics are available when querying the /stats endpoints as well.

Note

To avoid the need to create new task metadata endpoint versions in the future, additional metadata may be added to the version 4 output. We will not remove any existing metadata or change the metadata field names.

Turning on the task metadata endpoint

The task metadata endpoint is on by default for all Amazon ECS tasks run on AWS Fargate that use platform version 1.4.0 or later.

Task metadata endpoint version 4 paths

The following task metadata endpoints are available to containers:

${ECS_CONTAINER_METADATA_URI_V4}

This path returns metadata for the container.

${ECS_CONTAINER_METADATA_URI_V4}/task

This path returns metadata 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.

${ECS_CONTAINER_METADATA_URI_V4}/stats

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

Note

Amazon ECS tasks on AWS Fargate require that the container run for ~1 second prior to returning the container stats.

${ECS_CONTAINER_METADATA_URI_V4}/task/stats

This path returns Docker stats 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.

Note

Amazon ECS tasks on AWS Fargate require that the container run for ~1 second prior to returning the container stats.

Task metadata JSON response

The following metadata is returned in the task metadata endpoint (${ECS_CONTAINER_METADATA_URI_V4}/task) JSON response.

Cluster

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

VPCID

The VPC ID of the Amazon EC2 container instance. This field only appears for Amazon EC2 instances.

Note

The VPCID metadata is only included when using Amazon ECS container agent version 1.63.1 or later.

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 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 (Windows).

LaunchType

The launch type the task is using. When using cluster capacity providers, this indicates whether the task is using Fargate or EC2 infrastructure.

Note

This LaunchType metadata is only included when using Amazon ECS Linux container agent version 1.45.0 or later (Linux) or 1.0.0 or later (Windows).

EphemeralStorageMetrics

The reserved size and current usage of the ephemeral storage of this task.

Note

Fargate reserves space on disk. It is only used by Fargate. You aren't billed for it. It isn't shown in these metrics. However, you can see this additional storage in other tools such as df.

Utilized

The current ephemeral storage usage (in MiB) of this task.

Reserved

The reserved ephemeral storage (in MiB) of this task. The size of the ephemeral storage can't be changed in a running task. You can specify the ephermalStorage object in your task definition to change the amount of ephemeral storage. The ephermalStorage is specified in GiB, not MiB. The ephermalStorage and the EphemeralStorageMetrics are only available on Fargate Linux platform version 1.4.0 or later.

Containers

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

DockerId

The Docker ID for the container.

When you use Fargate, the id is a 32-digit hex followed by a 10 digit number.

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 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.

LogDriver

The log driver the container is using.

Note

This LogDriver metadata is only included when using Amazon ECS Linux container agent version 1.45.0 or later.

LogOptions

The log driver options defined for the container.

Note

This LogOptions metadata is only included when using Amazon ECS Linux container agent version 1.45.0 or later.

ContainerARN

The full Amazon Resource Name (ARN) of the container.

Note

This ContainerARN metadata is only included when using Amazon ECS Linux container agent version 1.45.0 or later.

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.

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.

Examples

The following examples show sample outputs from the task metadata endpoints for Amazon ECS tasks run on AWS Fargate.

From the container, you can use curl followed by the task meta data endpoint to query the endpoint for example curl ${ECS_CONTAINER_METADATA_URI_V4}/task.

Example container metadata response

When querying the ${ECS_CONTAINER_METADATA_URI_V4} endpoint you are returned only metadata about the container itself. The following is an example output.

{
    "DockerId": "cd189a933e5849daa93386466019ab50-2495160603",
    "Name": "curl",
    "DockerName": "curl",
    "Image": "111122223333.dkr.ecr.us-west-2.amazonaws.com/curltest:latest",
    "ImageID": "sha256:25f3695bedfb454a50f12d127839a68ad3caf91e451c1da073db34c542c4d2cb",
    "Labels": {
        "com.amazonaws.ecs.cluster": "arn:aws:ecs:us-west-2:111122223333:cluster/default",
        "com.amazonaws.ecs.container-name": "curl",
        "com.amazonaws.ecs.task-arn": "arn:aws:ecs:us-west-2:111122223333:task/default/cd189a933e5849daa93386466019ab50",
        "com.amazonaws.ecs.task-definition-family": "curltest",
        "com.amazonaws.ecs.task-definition-version": "2"
    },
    "DesiredStatus": "RUNNING",
    "KnownStatus": "RUNNING",
    "Limits": {
        "CPU": 10,
        "Memory": 128
    },
    "CreatedAt": "2020-10-08T20:09:11.44527186Z",
    "StartedAt": "2020-10-08T20:09:11.44527186Z",
    "Type": "NORMAL",
    "Networks": [
        {
            "NetworkMode": "awsvpc",
            "IPv4Addresses": [
                "192.0.2.3"
            ],
            "AttachmentIndex": 0,
            "MACAddress": "0a:de:f6:10:51:e5",
            "IPv4SubnetCIDRBlock": "192.0.2.0/24",
            "DomainNameServers": [
                "192.0.2.2"
            ],
            "DomainNameSearchList": [
                "us-west-2.compute.internal"
            ],
            "PrivateDNSName": "ip-10-0-0-222.us-west-2.compute.internal",
            "SubnetGatewayIpv4Address": "192.0.2.0/24"
        }
    ],
    "ContainerARN": "arn:aws:ecs:us-west-2:111122223333:container/05966557-f16c-49cb-9352-24b3a0dcd0e1",
    "LogOptions": {
        "awslogs-create-group": "true",
        "awslogs-group": "/ecs/containerlogs",
        "awslogs-region": "us-west-2",
        "awslogs-stream": "ecs/curl/cd189a933e5849daa93386466019ab50"
    },
    "LogDriver": "awslogs"
}

Example task metadata response

When querying the ${ECS_CONTAINER_METADATA_URI_V4}/task endpoint you are returned metadata about the task the container is part of. The following is an example output.

{
    "Cluster": "arn:aws:ecs:us-west-2:111122223333:cluster/default",
    "TaskARN": "arn:aws:ecs:us-west-2:111122223333:task/default/e9028f8d5d8e4f258373e7b93ce9a3c3",
    "Family": "curltest",
    "Revision": "3",
    "DesiredStatus": "RUNNING",
    "KnownStatus": "RUNNING",
    "Limits": {
        "CPU": 0.25,
        "Memory": 512
    },
    "PullStartedAt": "2020-10-08T20:47:16.053330955Z",
    "PullStoppedAt": "2020-10-08T20:47:19.592684631Z",
    "AvailabilityZone": "us-west-2a",
    "Containers": [
        {
            "DockerId": "e9028f8d5d8e4f258373e7b93ce9a3c3-2495160603",
            "Name": "curl",
            "DockerName": "curl",
            "Image": "111122223333.dkr.ecr.us-west-2.amazonaws.com/curltest:latest",
            "ImageID": "sha256:25f3695bedfb454a50f12d127839a68ad3caf91e451c1da073db34c542c4d2cb",
            "Labels": {
                "com.amazonaws.ecs.cluster": "arn:aws:ecs:us-west-2:111122223333:cluster/default",
                "com.amazonaws.ecs.container-name": "curl",
                "com.amazonaws.ecs.task-arn": "arn:aws:ecs:us-west-2:111122223333:task/default/e9028f8d5d8e4f258373e7b93ce9a3c3",
                "com.amazonaws.ecs.task-definition-family": "curltest",
                "com.amazonaws.ecs.task-definition-version": "3"
            },
            "DesiredStatus": "RUNNING",
            "KnownStatus": "RUNNING",
            "Limits": {
                "CPU": 10,
                "Memory": 128
            },
            "CreatedAt": "2020-10-08T20:47:20.567813946Z",
            "StartedAt": "2020-10-08T20:47:20.567813946Z",
            "Type": "NORMAL",
            "Networks": [
                {
                    "NetworkMode": "awsvpc",
                    "IPv4Addresses": [
                        "192.0.2.3"
                    ],
                    "IPv6Addresses": [
                        "2001:dB8:10b:1a00:32bf:a372:d80f:e958"
                    ],
                    "AttachmentIndex": 0,
                    "MACAddress": "02:b7:20:19:72:39",
                    "IPv4SubnetCIDRBlock": "192.0.2.0/24",
                    "IPv6SubnetCIDRBlock": "2600:1f13:10b:1a00::/64",
                    "DomainNameServers": [
                        "192.0.2.2"
                    ],
                    "DomainNameSearchList": [
                        "us-west-2.compute.internal"
                    ],
                    "PrivateDNSName": "ip-172-31-30-173.us-west-2.compute.internal",
                    "SubnetGatewayIpv4Address": "192.0.2.0/24"
                }
            ],
            "ClockDrift": {
                "ClockErrorBound": 0.5458234999999999,
                "ReferenceTimestamp": "2021-09-07T16:57:44Z",
                "ClockSynchronizationStatus": "SYNCHRONIZED"
             },
            "ContainerARN": "arn:aws:ecs:us-west-2:111122223333:container/1bdcca8b-f905-4ee6-885c-4064cb70f6e6",
            "LogOptions": {
                "awslogs-create-group": "true",
                "awslogs-group": "/ecs/containerlogs",
                "awslogs-region": "us-west-2",
                "awslogs-stream": "ecs/curl/e9028f8d5d8e4f258373e7b93ce9a3c3"
            },
            "LogDriver": "awslogs"
        }
    ],
    "LaunchType": "FARGATE"
}

Example task stats response

When querying the ${ECS_CONTAINER_METADATA_URI_V4}/task/stats endpoint you are returned network metrics about the task the container is part of. The following is an example output.

{
  "3d1f891cded94dc795608466cce8ddcf-464223573": {
    "read": "2020-10-08T21:24:44.938937019Z",
    "preread": "2020-10-08T21:24:34.938633969Z",
    "pids_stats": {},
    "blkio_stats": {
      "io_service_bytes_recursive": [
        {
          "major": 202,
          "minor": 26368,
          "op": "Read",
          "value": 638976
        },
        {
          "major": 202,
          "minor": 26368,
          "op": "Write",
          "value": 0
        },
        {
          "major": 202,
          "minor": 26368,
          "op": "Sync",
          "value": 638976
        },
        {
          "major": 202,
          "minor": 26368,
          "op": "Async",
          "value": 0
        },
        {
          "major": 202,
          "minor": 26368,
          "op": "Total",
          "value": 638976
        }
      ],
      "io_serviced_recursive": [
        {
          "major": 202,
          "minor": 26368,
          "op": "Read",
          "value": 12
        },
        {
          "major": 202,
          "minor": 26368,
          "op": "Write",
          "value": 0
        },
        {
          "major": 202,
          "minor": 26368,
          "op": "Sync",
          "value": 12
        },
        {
          "major": 202,
          "minor": 26368,
          "op": "Async",
          "value": 0
        },
        {
          "major": 202,
          "minor": 26368,
          "op": "Total",
          "value": 12
        }
      ],
      "io_queue_recursive": [],
      "io_service_time_recursive": [],
      "io_wait_time_recursive": [],
      "io_merged_recursive": [],
      "io_time_recursive": [],
      "sectors_recursive": []
    },
    "num_procs": 0,
    "storage_stats": {},
    "cpu_stats": {
      "cpu_usage": {
        "total_usage": 1137691504,
        "percpu_usage": [
          696479228,
          441212276,
          0,
          0,
          0,
          0,
          0,
          0,
          0,
          0,
          0,
          0,
          0,
          0,
          0
        ],
        "usage_in_kernelmode": 80000000,
        "usage_in_usermode": 810000000
      },
      "system_cpu_usage": 9393210000000,
      "online_cpus": 2,
      "throttling_data": {
        "periods": 0,
        "throttled_periods": 0,
        "throttled_time": 0
      }
    },
    "precpu_stats": {
      "cpu_usage": {
        "total_usage": 1136624601,
        "percpu_usage": [
          695639662,
          440984939,
          0,
          0,
          0,
          0,
          0,
          0,
          0,
          0,
          0,
          0,
          0,
          0,
          0
        ],
        "usage_in_kernelmode": 80000000,
        "usage_in_usermode": 810000000
      },
      "system_cpu_usage": 9373330000000,
      "online_cpus": 2,
      "throttling_data": {
        "periods": 0,
        "throttled_periods": 0,
        "throttled_time": 0
      }
    },
    "memory_stats": {
      "usage": 6504448,
      "max_usage": 8458240,
      "stats": {
        "active_anon": 1675264,
        "active_file": 557056,
        "cache": 651264,
        "dirty": 0,
        "hierarchical_memory_limit": 536870912,
        "hierarchical_memsw_limit": 9223372036854772000,
        "inactive_anon": 0,
        "inactive_file": 3088384,
        "mapped_file": 430080,
        "pgfault": 11034,
        "pgmajfault": 5,
        "pgpgin": 8436,
        "pgpgout": 7137,
        "rss": 4669440,
        "rss_huge": 0,
        "total_active_anon": 1675264,
        "total_active_file": 557056,
        "total_cache": 651264,
        "total_dirty": 0,
        "total_inactive_anon": 0,
        "total_inactive_file": 3088384,
        "total_mapped_file": 430080,
        "total_pgfault": 11034,
        "total_pgmajfault": 5,
        "total_pgpgin": 8436,
        "total_pgpgout": 7137,
        "total_rss": 4669440,
        "total_rss_huge": 0,
        "total_unevictable": 0,
        "total_writeback": 0,
        "unevictable": 0,
        "writeback": 0
      },
      "limit": 9223372036854772000
    },
    "name": "curltest",
    "id": "3d1f891cded94dc795608466cce8ddcf-464223573",
    "networks": {
      "eth1": {
        "rx_bytes": 2398415937,
        "rx_packets": 1898631,
        "rx_errors": 0,
        "rx_dropped": 0,
        "tx_bytes": 1259037719,
        "tx_packets": 428002,
        "tx_errors": 0,
        "tx_dropped": 0
      }
    },
    "network_rate_stats": {
      "rx_bytes_per_sec": 43.298687872232854,
      "tx_bytes_per_sec": 215.39347269466413
    }
  }
}