Table Of Contents

Feedback

User Guide

First time using the AWS CLI? See the User Guide for help getting started.

[ aws . ecs ]

describe-task-definition

Description

Describes a task definition. You can specify a family and revision to find information about a specific task definition, or you can simply specify the family to find the latest ACTIVE revision in that family.

Note

You can only describe INACTIVE task definitions while an active task or service references them.

See also: AWS API Documentation

Synopsis

  describe-task-definition
--task-definition <value>
[--cli-input-json <value>]
[--generate-cli-skeleton <value>]

Options

--task-definition (string)

The family for the latest ACTIVE revision, family and revision (family:revision ) for a specific revision in the family, or full Amazon Resource Name (ARN) of the task definition to describe.

--cli-input-json (string) Performs service operation based on the JSON string provided. The JSON string follows the format provided by --generate-cli-skeleton. If other arguments are provided on the command line, the CLI values will override the JSON-provided values.

--generate-cli-skeleton (string) Prints a JSON skeleton to standard output without sending an API request. If provided with no value or the value input, prints a sample input JSON that can be used as an argument for --cli-input-json. If provided with the value output, it validates the command inputs and returns a sample output JSON for that command.

Examples

To describe a task definition

This example command provides a description of the specified task definition.

Command:

aws ecs describe-task-definition --task-definition hello_world:8

Output:

{
    "taskDefinition": {
        "volumes": [],
        "taskDefinitionArn": "arn:aws:ecs:us-east-1:<aws_account_id>:task-definition/hello_world:8",
        "containerDefinitions": [
            {
                "environment": [],
                "name": "wordpress",
                "links": [
                    "mysql"
                ],
                "mountPoints": [],
                "image": "wordpress",
                "essential": true,
                "portMappings": [
                    {
                        "containerPort": 80,
                        "hostPort": 80
                    }
                ],
                "memory": 500,
                "cpu": 10,
                "volumesFrom": []
            },
            {
                "environment": [
                    {
                        "name": "MYSQL_ROOT_PASSWORD",
                        "value": "password"
                    }
                ],
                "name": "mysql",
                "mountPoints": [],
                "image": "mysql",
                "cpu": 10,
                "portMappings": [],
                "memory": 500,
                "essential": true,
                "volumesFrom": []
            }
        ],
        "family": "hello_world",
        "revision": 8
    }
}

Output

taskDefinition -> (structure)

The full task definition description.

taskDefinitionArn -> (string)

The full Amazon Resource Name (ARN) of the task definition.

containerDefinitions -> (list)

A list of container definitions in JSON format that describe the different containers that make up your task. For more information about container definition parameters and defaults, see Amazon ECS Task Definitions in the Amazon Elastic Container Service Developer Guide .

(structure)

Container definitions are used in task definitions to describe the different containers that are launched as part of a task.

name -> (string)

The name of a container. If you are linking multiple containers together in a task definition, the name of one container can be entered in the links of another container to connect the containers. Up to 255 letters (uppercase and lowercase), numbers, hyphens, and underscores are allowed. This parameter maps to name in the Create a container section of the Docker Remote API and the --name option to docker run .

image -> (string)

The image used to start a container. This string is passed directly to the Docker daemon. Images in the Docker Hub registry are available by default. Other repositories are specified with either `` repository-url /image :tag `` or `` repository-url /image @*digest* `` . Up to 255 letters (uppercase and lowercase), numbers, hyphens, underscores, colons, periods, forward slashes, and number signs are allowed. This parameter maps to Image in the Create a container section of the Docker Remote API and the IMAGE parameter of docker run .

  • Images in Amazon ECR repositories can be specified by either using the full registry/repository:tag or registry/repository@digest . For example, 012345678910.dkr.ecr.region-name.amazonaws.com/repository-name:latest or 012345678910.dkr.ecr.region-name.amazonaws.com/repository-name@sha256:94afd1f2e64d908bc90dbca0035a5b567EXAMPLE .
  • Images in official repositories on Docker Hub use a single name (for example, ubuntu or mongo ).
  • Images in other repositories on Docker Hub are qualified with an organization name (for example, amazon/amazon-ecs-agent ).
  • Images in other online repositories are qualified further by a domain name (for example, quay.io/assemblyline/ubuntu ).

cpu -> (integer)

The number of cpu units reserved for the container. This parameter maps to CpuShares in the Create a container section of the Docker Remote API and the --cpu-shares option to docker run .

This field is optional for tasks using the Fargate launch type, and the only requirement is that the total amount of CPU reserved for all containers within a task be lower than the task-level cpu value.

Note

You can determine the number of CPU units that are available per EC2 instance type by multiplying the vCPUs listed for that instance type on the Amazon EC2 Instances detail page by 1,024.

For example, if you run a single-container task on a single-core instance type with 512 CPU units specified for that container, and that is the only task running on the container instance, that container could use the full 1,024 CPU unit share at any given time. However, if you launched another copy of the same task on that container instance, each task would be guaranteed a minimum of 512 CPU units when needed, and each container could float to higher CPU usage if the other container was not using it, but if both tasks were 100% active all of the time, they would be limited to 512 CPU units.

Linux containers share unallocated CPU units with other containers on the container instance with the same ratio as their allocated amount. For example, if you run a single-container task on a single-core instance type with 512 CPU units specified for that container, and that is the only task running on the container instance, that container could use the full 1,024 CPU unit share at any given time. However, if you launched another copy of the same task on that container instance, each task would be guaranteed a minimum of 512 CPU units when needed, and each container could float to higher CPU usage if the other container was not using it, but if both tasks were 100% active all of the time, they would be limited to 512 CPU units.

On Linux container instances, the Docker daemon on the container instance uses the CPU value to calculate the relative CPU share ratios for running containers. For more information, see CPU share constraint in the Docker documentation. The minimum valid CPU share value that the Linux kernel will allow is 2; however, the CPU parameter is not required, and you can use CPU values below 2 in your container definitions. For CPU values below 2 (including null), the behavior varies based on your Amazon ECS container agent version:

  • Agent versions less than or equal to 1.1.0: Null and zero CPU values are passed to Docker as 0, which Docker then converts to 1,024 CPU shares. CPU values of 1 are passed to Docker as 1, which the Linux kernel converts to 2 CPU shares.
  • Agent versions greater than or equal to 1.2.0: Null, zero, and CPU values of 1 are passed to Docker as 2.

On Windows container instances, the CPU limit is enforced as an absolute limit, or a quota. Windows containers only have access to the specified amount of CPU that is described in the task definition.

memory -> (integer)

The hard limit (in MiB) of memory to present to the container. If your container attempts to exceed the memory specified here, the container is killed. This parameter maps to Memory in the Create a container section of the Docker Remote API and the --memory option to docker run .

If your containers will be part of a task using the Fargate launch type, this field is optional and the only requirement is that the total amount of memory reserved for all containers within a task be lower than the task memory value.

For containers that will be part of a task using the EC2 launch type, you must specify a non-zero integer for one or both of memory or memoryReservation in container definitions. If you specify both, memory must be greater than memoryReservation . If you specify memoryReservation , then that value is subtracted from the available memory resources for the container instance on which the container is placed; otherwise, the value of memory is used.

The Docker daemon reserves a minimum of 4 MiB of memory for a container, so you should not specify fewer than 4 MiB of memory for your containers.

memoryReservation -> (integer)

The soft limit (in MiB) of memory to reserve for the container. When system memory is under heavy contention, Docker attempts to keep the container memory to this soft limit; however, your container can consume more memory when it needs to, up to either the hard limit specified with the memory parameter (if applicable), or all of the available memory on the container instance, whichever comes first. This parameter maps to MemoryReservation in the Create a container section of the Docker Remote API and the --memory-reservation option to docker run .

You must specify a non-zero integer for one or both of memory or memoryReservation in container definitions. If you specify both, memory must be greater than memoryReservation . If you specify memoryReservation , then that value is subtracted from the available memory resources for the container instance on which the container is placed; otherwise, the value of memory is used.

For example, if your container normally uses 128 MiB of memory, but occasionally bursts to 256 MiB of memory for short periods of time, you can set a memoryReservation of 128 MiB, and a memory hard limit of 300 MiB. This configuration would allow the container to only reserve 128 MiB of memory from the remaining resources on the container instance, but also allow the container to consume more memory resources when needed.

links -> (list)

The link parameter allows containers to communicate with each other without the need for port mappings. Only supported if the network mode of a task definition is set to bridge . The name:internalName construct is analogous to name:alias in Docker links. Up to 255 letters (uppercase and lowercase), numbers, hyphens, and underscores are allowed. For more information about linking Docker containers, go to https://docs.docker.com/engine/userguide/networking/default_network/dockerlinks/ . This parameter maps to Links in the Create a container section of the Docker Remote API and the --link option to ` docker run https://docs.docker.com/engine/reference/commandline/run/`__ .

Note

This parameter is not supported for Windows containers.

Warning

Containers that are collocated on a single container instance may be able to communicate with each other without requiring links or host port mappings. Network isolation is achieved on the container instance using security groups and VPC settings.

(string)

portMappings -> (list)

The list of port mappings for the container. Port mappings allow containers to access ports on the host container instance to send or receive traffic.

For task definitions that use the awsvpc network mode, you should only specify the containerPort . The hostPort can be left blank or it must be the same value as the containerPort .

Port mappings on Windows use the NetNAT gateway address rather than localhost . There is no loopback for port mappings on Windows, so you cannot access a container's mapped port from the host itself.

This parameter maps to PortBindings in the Create a container section of the Docker Remote API and the --publish option to docker run . If the network mode of a task definition is set to none , then you can't specify port mappings. If the network mode of a task definition is set to host , then host ports must either be undefined or they must match the container port in the port mapping.

Note

After a task reaches the RUNNING status, manual and automatic host and container port assignments are visible in the Network Bindings section of a container description for a selected task in the Amazon ECS console, or the networkBindings section describe-tasks responses.

(structure)

Port mappings allow containers to access ports on the host container instance to send or receive traffic. Port mappings are specified as part of the container definition.

If using containers in a task with the Fargate launch type, exposed ports should be specified using containerPort . The hostPort can be left blank or it must be the same value as the containerPort .

After a task reaches the RUNNING status, manual and automatic host and container port assignments are visible in the networkBindings section of describe-tasks API responses.

containerPort -> (integer)

The port number on the container that is bound to the user-specified or automatically assigned host port.

If using containers in a task with the Fargate launch type, exposed ports should be specified using containerPort .

If using containers in a task with the EC2 launch type and you specify a container port and not a host port, your container automatically receives a host port in the ephemeral port range (for more information, see hostPort ). Port mappings that are automatically assigned in this way do not count toward the 100 reserved ports limit of a container instance.

hostPort -> (integer)

The port number on the container instance to reserve for your container.

If using containers in a task with the Fargate launch type, the hostPort can either be left blank or needs to be the same value as the containerPort .

If using containers in a task with the EC2 launch type, you can specify a non-reserved host port for your container port mapping, or you can omit the hostPort (or set it to 0 ) while specifying a containerPort and your container automatically receives a port in the ephemeral port range for your container instance operating system and Docker version.

The default ephemeral port range for Docker version 1.6.0 and later is listed on the instance under /proc/sys/net/ipv4/ip_local_port_range ; if this kernel parameter is unavailable, the default ephemeral port range from 49153 through 65535 is used. You should not attempt to specify a host port in the ephemeral port range as these are reserved for automatic assignment. In general, ports below 32768 are outside of the ephemeral port range.

Note

The default ephemeral port range from 49153 through 65535 is always used for Docker versions before 1.6.0.

The default reserved ports are 22 for SSH, the Docker ports 2375 and 2376, and the Amazon ECS container agent ports 51678 and 51679. Any host port that was previously specified in a running task is also reserved while the task is running (after a task stops, the host port is released). The current reserved ports are displayed in the remainingResources of describe-container-instances output, and a container instance may have up to 100 reserved ports at a time, including the default reserved ports (automatically assigned ports do not count toward the 100 reserved ports limit).

protocol -> (string)

The protocol used for the port mapping. Valid values are tcp and udp . The default is tcp .

essential -> (boolean)

If the essential parameter of a container is marked as true , and that container fails or stops for any reason, all other containers that are part of the task are stopped. If the essential parameter of a container is marked as false , then its failure does not affect the rest of the containers in a task. If this parameter is omitted, a container is assumed to be essential.

All tasks must have at least one essential container. If you have an application that is composed of multiple containers, you should group containers that are used for a common purpose into components, and separate the different components into multiple task definitions. For more information, see Application Architecture in the Amazon Elastic Container Service Developer Guide .

entryPoint -> (list)

Warning

Early versions of the Amazon ECS container agent do not properly handle entryPoint parameters. If you have problems using entryPoint , update your container agent or enter your commands and arguments as command array items instead.

The entry point that is passed to the container. This parameter maps to Entrypoint in the Create a container section of the Docker Remote API and the --entrypoint option to docker run . For more information, see https://docs.docker.com/engine/reference/builder/#entrypoint .

(string)

command -> (list)

The command that is passed to the container. This parameter maps to Cmd in the Create a container section of the Docker Remote API and the COMMAND parameter to docker run . For more information, see https://docs.docker.com/engine/reference/builder/#cmd .

(string)

environment -> (list)

The environment variables to pass to a container. This parameter maps to Env in the Create a container section of the Docker Remote API and the --env option to docker run .

Warning

We do not recommend using plaintext environment variables for sensitive information, such as credential data.

(structure)

A key and value pair object.

name -> (string)

The name of the key value pair. For environment variables, this is the name of the environment variable.

value -> (string)

The value of the key value pair. For environment variables, this is the value of the environment variable.

mountPoints -> (list)

The mount points for data volumes in your container.

This parameter maps to Volumes in the Create a container section of the Docker Remote API and the --volume option to docker run .

Windows containers can mount whole directories on the same drive as $env:ProgramData . Windows containers cannot mount directories on a different drive, and mount point cannot be across drives.

(structure)

Details on a volume mount point that is used in a container definition.

sourceVolume -> (string)

The name of the volume to mount.

containerPath -> (string)

The path on the container to mount the host volume at.

readOnly -> (boolean)

If this value is true , the container has read-only access to the volume. If this value is false , then the container can write to the volume. The default value is false .

volumesFrom -> (list)

Data volumes to mount from another container. This parameter maps to VolumesFrom in the Create a container section of the Docker Remote API and the --volumes-from option to docker run .

(structure)

Details on a data volume from another container in the same task definition.

sourceContainer -> (string)

The name of another container within the same task definition to mount volumes from.

readOnly -> (boolean)

If this value is true , the container has read-only access to the volume. If this value is false , then the container can write to the volume. The default value is false .

linuxParameters -> (structure)

Linux-specific modifications that are applied to the container, such as Linux KernelCapabilities .

Note

This parameter is not supported for Windows containers or tasks using the Fargate launch type.

capabilities -> (structure)

The Linux capabilities for the container that are added to or dropped from the default configuration provided by Docker.

add -> (list)

The Linux capabilities for the container that have been added to the default configuration provided by Docker. This parameter maps to CapAdd in the Create a container section of the Docker Remote API and the --cap-add option to docker run .

Valid values: "ALL" | "AUDIT_CONTROL" | "AUDIT_WRITE" | "BLOCK_SUSPEND" | "CHOWN" | "DAC_OVERRIDE" | "DAC_READ_SEARCH" | "FOWNER" | "FSETID" | "IPC_LOCK" | "IPC_OWNER" | "KILL" | "LEASE" | "LINUX_IMMUTABLE" | "MAC_ADMIN" | "MAC_OVERRIDE" | "MKNOD" | "NET_ADMIN" | "NET_BIND_SERVICE" | "NET_BROADCAST" | "NET_RAW" | "SETFCAP" | "SETGID" | "SETPCAP" | "SETUID" | "SYS_ADMIN" | "SYS_BOOT" | "SYS_CHROOT" | "SYS_MODULE" | "SYS_NICE" | "SYS_PACCT" | "SYS_PTRACE" | "SYS_RAWIO" | "SYS_RESOURCE" | "SYS_TIME" | "SYS_TTY_CONFIG" | "SYSLOG" | "WAKE_ALARM"

(string)

drop -> (list)

The Linux capabilities for the container that have been removed from the default configuration provided by Docker. This parameter maps to CapDrop in the Create a container section of the Docker Remote API and the --cap-drop option to docker run .

Valid values: "ALL" | "AUDIT_CONTROL" | "AUDIT_WRITE" | "BLOCK_SUSPEND" | "CHOWN" | "DAC_OVERRIDE" | "DAC_READ_SEARCH" | "FOWNER" | "FSETID" | "IPC_LOCK" | "IPC_OWNER" | "KILL" | "LEASE" | "LINUX_IMMUTABLE" | "MAC_ADMIN" | "MAC_OVERRIDE" | "MKNOD" | "NET_ADMIN" | "NET_BIND_SERVICE" | "NET_BROADCAST" | "NET_RAW" | "SETFCAP" | "SETGID" | "SETPCAP" | "SETUID" | "SYS_ADMIN" | "SYS_BOOT" | "SYS_CHROOT" | "SYS_MODULE" | "SYS_NICE" | "SYS_PACCT" | "SYS_PTRACE" | "SYS_RAWIO" | "SYS_RESOURCE" | "SYS_TIME" | "SYS_TTY_CONFIG" | "SYSLOG" | "WAKE_ALARM"

(string)

devices -> (list)

Any host devices to expose to the container. This parameter maps to Devices in the Create a container section of the Docker Remote API and the --device option to docker run .

(structure)

An object representing a container instance host device.

hostPath -> (string)

The path for the device on the host container instance.

containerPath -> (string)

The path inside the container at which to expose the host device.

permissions -> (list)

The explicit permissions to provide to the container for the device. By default, the container has permissions for read , write , and mknod for the device.

(string)

initProcessEnabled -> (boolean)

Run an init process inside the container that forwards signals and reaps processes. This parameter maps to the --init option to docker run . This parameter requires version 1.25 of the Docker Remote API or greater on your container instance. To check the Docker Remote API version on your container instance, log in to your container instance and run the following command: sudo docker version | grep "Server API version"

hostname -> (string)

The hostname to use for your container. This parameter maps to Hostname in the Create a container section of the Docker Remote API and the --hostname option to docker run .

user -> (string)

The user name to use inside the container. This parameter maps to User in the Create a container section of the Docker Remote API and the --user option to docker run .

Note

This parameter is not supported for Windows containers.

workingDirectory -> (string)

The working directory in which to run commands inside the container. This parameter maps to WorkingDir in the Create a container section of the Docker Remote API and the --workdir option to docker run .

disableNetworking -> (boolean)

When this parameter is true, networking is disabled within the container. This parameter maps to NetworkDisabled in the Create a container section of the Docker Remote API .

Note

This parameter is not supported for Windows containers.

privileged -> (boolean)

When this parameter is true, the container is given elevated privileges on the host container instance (similar to the root user). This parameter maps to Privileged in the Create a container section of the Docker Remote API and the --privileged option to docker run .

Note

This parameter is not supported for Windows containers or tasks using the Fargate launch type.

readonlyRootFilesystem -> (boolean)

When this parameter is true, the container is given read-only access to its root file system. This parameter maps to ReadonlyRootfs in the Create a container section of the Docker Remote API and the --read-only option to docker run .

Note

This parameter is not supported for Windows containers.

dnsServers -> (list)

A list of DNS servers that are presented to the container. This parameter maps to Dns in the Create a container section of the Docker Remote API and the --dns option to docker run .

Note

This parameter is not supported for Windows containers.

(string)

dnsSearchDomains -> (list)

A list of DNS search domains that are presented to the container. This parameter maps to DnsSearch in the Create a container section of the Docker Remote API and the --dns-search option to docker run .

Note

This parameter is not supported for Windows containers.

(string)

extraHosts -> (list)

A list of hostnames and IP address mappings to append to the /etc/hosts file on the container. If using the Fargate launch type, this may be used to list non-Fargate hosts you want the container to talk to. This parameter maps to ExtraHosts in the Create a container section of the Docker Remote API and the --add-host option to docker run .

Note

This parameter is not supported for Windows containers.

(structure)

Hostnames and IP address entries that are added to the /etc/hosts file of a container via the extraHosts parameter of its ContainerDefinition .

hostname -> (string)

The hostname to use in the /etc/hosts entry.

ipAddress -> (string)

The IP address to use in the /etc/hosts entry.

dockerSecurityOptions -> (list)

A list of strings to provide custom labels for SELinux and AppArmor multi-level security systems. This field is not valid for containers in tasks using the Fargate launch type.

This parameter maps to SecurityOpt in the Create a container section of the Docker Remote API and the --security-opt option to docker run .

Note

The Amazon ECS container agent running on a container instance must register with the ECS_SELINUX_CAPABLE=true or ECS_APPARMOR_CAPABLE=true environment variables before containers placed on that instance can use these security options. For more information, see Amazon ECS Container Agent Configuration in the Amazon Elastic Container Service Developer Guide .

This parameter is not supported for Windows containers.

(string)

dockerLabels -> (map)

A key/value map of labels to add to the container. This parameter maps to Labels in the Create a container section of the Docker Remote API and the --label option to docker run . This parameter requires version 1.18 of the Docker Remote API or greater on your container instance. To check the Docker Remote API version on your container instance, log in to your container instance and run the following command: sudo docker version | grep "Server API version"

key -> (string)

value -> (string)

ulimits -> (list)

A list of ulimits to set in the container. This parameter maps to Ulimits in the Create a container section of the Docker Remote API and the --ulimit option to docker run . Valid naming values are displayed in the Ulimit data type. This parameter requires version 1.18 of the Docker Remote API or greater on your container instance. To check the Docker Remote API version on your container instance, log in to your container instance and run the following command: sudo docker version | grep "Server API version"

Note

This parameter is not supported for Windows containers.

(structure)

The ulimit settings to pass to the container.

name -> (string)

The type of the ulimit .

softLimit -> (integer)

The soft limit for the ulimit type.

hardLimit -> (integer)

The hard limit for the ulimit type.

logConfiguration -> (structure)

The log configuration specification for the container.

If using the Fargate launch type, the only supported value is awslogs .

This parameter maps to LogConfig in the Create a container section of the Docker Remote API and the --log-driver option to docker run . By default, containers use the same logging driver that the Docker daemon uses; however the container may use a different logging driver than the Docker daemon by specifying a log driver with this parameter in the container definition. To use a different logging driver for a container, the log system must be configured properly on the container instance (or on a different log server for remote logging options). For more information on the options for different supported log drivers, see Configure logging drivers in the Docker documentation.

Note

Amazon ECS currently supports a subset of the logging drivers available to the Docker daemon (shown in the LogConfiguration data type). Additional log drivers may be available in future releases of the Amazon ECS container agent.

This parameter requires version 1.18 of the Docker Remote API or greater on your container instance. To check the Docker Remote API version on your container instance, log in to your container instance and run the following command: sudo docker version | grep "Server API version"

Note

The Amazon ECS container agent running on a container instance must register the logging drivers available on that instance with the ECS_AVAILABLE_LOGGING_DRIVERS environment variable before containers placed on that instance can use these log configuration options. For more information, see Amazon ECS Container Agent Configuration in the Amazon Elastic Container Service Developer Guide .

logDriver -> (string)

The log driver to use for the container. The valid values listed for this parameter are log drivers that the Amazon ECS container agent can communicate with by default. If using the Fargate launch type, the only supported value is awslogs . For more information about using the awslogs driver, see Using the awslogs Log Driver in the Amazon Elastic Container Service Developer Guide .

Note

If you have a custom driver that is not listed above that you would like to work with the Amazon ECS container agent, you can fork the Amazon ECS container agent project that is available on GitHub and customize it to work with that driver. We encourage you to submit pull requests for changes that you would like to have included. However, Amazon Web Services does not currently support running modified copies of this software.

This parameter requires version 1.18 of the Docker Remote API or greater on your container instance. To check the Docker Remote API version on your container instance, log in to your container instance and run the following command: sudo docker version | grep "Server API version"

options -> (map)

The configuration options to send to the log driver. This parameter requires version 1.19 of the Docker Remote API or greater on your container instance. To check the Docker Remote API version on your container instance, log in to your container instance and run the following command: sudo docker version | grep "Server API version"

key -> (string)

value -> (string)

family -> (string)

The family of your task definition, used as the definition name.

taskRoleArn -> (string)

The ARN of the IAM role that containers in this task can assume. All containers in this task are granted the permissions that are specified in this role.

IAM roles for tasks on Windows require that the -EnableTaskIAMRole option is set when you launch the Amazon ECS-optimized Windows AMI. Your containers must also run some configuration code in order to take advantage of the feature. For more information, see Windows IAM Roles for Tasks in the Amazon Elastic Container Service Developer Guide .

executionRoleArn -> (string)

The Amazon Resource Name (ARN) of the task execution role that the Amazon ECS container agent and the Docker daemon can assume.

networkMode -> (string)

The Docker networking mode to use for the containers in the task. The valid values are none , bridge , awsvpc , and host . The default Docker network mode is bridge . If using the Fargate launch type, the awsvpc network mode is required. If using the EC2 launch type, any network mode can be used. If the network mode is set to none , you can't specify port mappings in your container definitions, and the task's containers do not have external connectivity. The host and awsvpc network modes offer the highest networking performance for containers because they use the EC2 network stack instead of the virtualized network stack provided by the bridge mode.

With the host and awsvpc network modes, exposed container ports are mapped directly to the corresponding host port (for the host network mode) or the attached elastic network interface port (for the awsvpc network mode), so you cannot take advantage of dynamic host port mappings.

If the network mode is awsvpc , the task is allocated an Elastic Network Interface, and you must specify a NetworkConfiguration when you create a service or run a task with the task definition. For more information, see Task Networking in the Amazon Elastic Container Service Developer Guide .

Note

Currently, only the Amazon ECS-optimized AMI, other Amazon Linux variants with the ecs-init package, or AWS Fargate infrastructure support the awsvpc network mode.

If the network mode is host , you can't run multiple instantiations of the same task on a single container instance when port mappings are used.

Docker for Windows uses different network modes than Docker for Linux. When you register a task definition with Windows containers, you must not specify a network mode. If you use the console to register a task definition with Windows containers, you must choose the default network mode object.

For more information, see Network settings in the Docker run reference .

revision -> (integer)

The revision of the task in a particular family. The revision is a version number of a task definition in a family. When you register a task definition for the first time, the revision is 1 ; each time you register a new revision of a task definition in the same family, the revision value always increases by one (even if you have deregistered previous revisions in this family).

volumes -> (list)

The list of volumes in a task.

If you are using the Fargate launch type, the host and sourcePath parameters are not supported.

For more information about volume definition parameters and defaults, see Amazon ECS Task Definitions in the Amazon Elastic Container Service Developer Guide .

(structure)

A data volume used in a task definition.

name -> (string)

The name of the volume. Up to 255 letters (uppercase and lowercase), numbers, hyphens, and underscores are allowed. This name is referenced in the sourceVolume parameter of container definition mountPoints .

host -> (structure)

The contents of the host parameter determine whether your data volume persists on the host container instance and where it is stored. If the host parameter is empty, then the Docker daemon assigns a host path for your data volume, but the data is not guaranteed to persist after the containers associated with it stop running.

Windows containers can mount whole directories on the same drive as $env:ProgramData . Windows containers cannot mount directories on a different drive, and mount point cannot be across drives. For example, you can mount C:\my\path:C:\my\path and D:\:D:\ , but not D:\my\path:C:\my\path or D:\:C:\my\path .

sourcePath -> (string)

The path on the host container instance that is presented to the container. If this parameter is empty, then the Docker daemon has assigned a host path for you. If the host parameter contains a sourcePath file location, then the data volume persists at the specified location on the host container instance until you delete it manually. If the sourcePath value does not exist on the host container instance, the Docker daemon creates it. If the location does exist, the contents of the source path folder are exported.

If you are using the Fargate launch type, the sourcePath parameter is not supported.

status -> (string)

The status of the task definition.

requiresAttributes -> (list)

The container instance attributes required by your task. This field is not valid if using the Fargate launch type for your task.

(structure)

An attribute is a name-value pair associated with an Amazon ECS object. Attributes enable you to extend the Amazon ECS data model by adding custom metadata to your resources. For more information, see Attributes in the Amazon Elastic Container Service Developer Guide .

name -> (string)

The name of the attribute. Up to 128 letters (uppercase and lowercase), numbers, hyphens, underscores, and periods are allowed.

value -> (string)

The value of the attribute. Up to 128 letters (uppercase and lowercase), numbers, hyphens, underscores, periods, at signs (@), forward slashes, colons, and spaces are allowed.

targetType -> (string)

The type of the target with which to attach the attribute. This parameter is required if you use the short form ID for a resource instead of the full ARN.

targetId -> (string)

The ID of the target. You can specify the short form ID for a resource or the full Amazon Resource Name (ARN).

placementConstraints -> (list)

An array of placement constraint objects to use for tasks. This field is not valid if using the Fargate launch type for your task.

(structure)

An object representing a constraint on task placement in the task definition.

If you are using the Fargate launch type, task placement contraints are not supported.

For more information, see Task Placement Constraints in the Amazon Elastic Container Service Developer Guide .

type -> (string)

The type of constraint. The DistinctInstance constraint ensures that each task in a particular group is running on a different container instance. The MemberOf constraint restricts selection to be from a group of valid candidates.

expression -> (string)

A cluster query language expression to apply to the constraint. For more information, see Cluster Query Language in the Amazon Elastic Container Service Developer Guide .

compatibilities -> (list)

The launch type to use with your task. For more information, see Amazon ECS Launch Types in the Amazon Elastic Container Service Developer Guide .

(string)

requiresCompatibilities -> (list)

The launch type the task is using.

(string)

cpu -> (string)

The number of cpu units used by the task. If using the EC2 launch type, this field is optional and any value can be used. If using the Fargate launch type, this field is required and you must use one of the following values, which determines your range of valid values for the memory parameter:

  • 256 (.25 vCPU) - Available memory values: 512MB, 1GB, 2GB
  • 512 (.5 vCPU) - Available memory values: 1GB, 2GB, 3GB, 4GB
  • 1024 (1 vCPU) - Available memory values: 2GB, 3GB, 4GB, 5GB, 6GB, 7GB, 8GB
  • 2048 (2 vCPU) - Available memory values: Between 4GB and 16GB in 1GB increments
  • 4096 (4 vCPU) - Available memory values: Between 8GB and 30GB in 1GB increments

memory -> (string)

The amount (in MiB) of memory used by the task. If using the EC2 launch type, this field is optional and any value can be used. If using the Fargate launch type, this field is required and you must use one of the following values, which determines your range of valid values for the cpu parameter:

  • 512MB, 1GB, 2GB - Available cpu values: 256 (.25 vCPU)
  • 1GB, 2GB, 3GB, 4GB - Available cpu values: 512 (.5 vCPU)
  • 2GB, 3GB, 4GB, 5GB, 6GB, 7GB, 8GB - Available cpu values: 1024 (1 vCPU)
  • Between 4GB and 16GB in 1GB increments - Available cpu values: 2048 (2 vCPU)
  • Between 8GB and 30GB in 1GB increments - Available cpu values: 4096 (4 vCPU)