ContainerDefinition

Gets and sets the property Command.

The command that's passed to the container. This parameter maps to Cmd in the docker container create command and the COMMAND parameter to docker run. If there are multiple arguments, each argument is a separated string in the array.

Gets and sets the property Cpu.

The number of cpu units reserved for the container. This parameter maps to CpuShares in the docker container create commandand 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.

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's 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 is guaranteed a minimum of 512 CPU units when needed. Moreover, each container could float to higher CPU usage if the other container was not using it. 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. The minimum valid CPU share value that the Linux kernel allows is 2, and the maximum valid CPU share value that the Linux kernel allows is 262144. However, the CPU parameter isn't required, and you can use CPU values below 2 or above 262144 in your container definitions. For CPU values below 2 (including null) or above 262144, 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 two 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.

• Agent versions greater than or equal to 1.84.0: CPU values greater than 256 vCPU are passed to Docker as 256, which is equivalent to 262144 CPU shares.

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's described in the task definition. A null or zero CPU value is passed to Docker as 0, which Windows interprets as 1% of one CPU.

Gets and sets the property CredentialSpecs.

A list of ARNs in SSM or Amazon S3 to a credential spec (CredSpec) file that configures the container for Active Directory authentication. We recommend that you use this parameter instead of the dockerSecurityOptions. The maximum number of ARNs is 1.

There are two formats for each ARN.

credentialspecdomainless:MyARN

You use credentialspecdomainless:MyARN to provide a CredSpec with an additional section for a secret in Secrets Manager. You provide the login credentials to the domain in the secret.

Each task that runs on any container instance can join different domains.

You can use this format without joining the container instance to a domain.

credentialspec:MyARN

You use credentialspec:MyARN to provide a CredSpec for a single domain.

You must join the container instance to the domain before you start any tasks that use this task definition.

In both formats, replace MyARN with the ARN in SSM or Amazon S3.

If you provide a credentialspecdomainless:MyARN, the credspec must provide a ARN in Secrets Manager for a secret containing the username, password, and the domain to connect to. For better security, the instance isn't joined to the domain for domainless authentication. Other applications on the instance can't use the domainless credentials. You can use this parameter to run tasks on the same instance, even it the tasks need to join different domains. For more information, see Using gMSAs for Windows Containers and Using gMSAs for Linux Containers.

Gets and sets the property DependsOn.

The dependencies defined for container startup and shutdown. A container can contain multiple dependencies on other containers in a task definition. When a dependency is defined for container startup, for container shutdown it is reversed.

For tasks using the EC2 launch type, the container instances require at least version 1.26.0 of the container agent to turn on container dependencies. However, we recommend using the latest container agent version. For information about checking your agent version and updating to the latest version, see Updating the Amazon ECS Container Agent in the Amazon Elastic Container Service Developer Guide. If you're using an Amazon ECS-optimized Linux AMI, your instance needs at least version 1.26.0-1 of the ecs-init package. If your container instances are launched from version 20190301 or later, then they contain the required versions of the container agent and ecs-init. For more information, see Amazon ECS-optimized Linux AMI in the Amazon Elastic Container Service Developer Guide.

For tasks using the Fargate launch type, the task or service requires the following platforms:

• Linux platform version 1.3.0 or later.

• Windows platform version 1.0.0 or later.

Gets and sets the property DisableNetworking.

When this parameter is true, networking is off within the container. This parameter maps to NetworkDisabled in the docker container create command.

Gets and sets the property DnsSearchDomains.

A list of DNS search domains that are presented to the container. This parameter maps to DnsSearch in the docker container create command and the --dns-search option to docker run.

Gets and sets the property DnsServers.

A list of DNS servers that are presented to the container. This parameter maps to Dns in the docker container create command and the --dns option to docker run.

Gets and sets the property DockerLabels.

A key/value map of labels to add to the container. This parameter maps to Labels in the docker container create command 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 --format '{{.Server.APIVersion}}'

Gets and sets the property DockerSecurityOptions.

A list of strings to provide custom configuration for multiple security systems. This field isn't valid for containers in tasks using the Fargate launch type.

For Linux tasks on EC2, this parameter can be used to reference custom labels for SELinux and AppArmor multi-level security systems.

For any tasks on EC2, this parameter can be used to reference a credential spec file that configures a container for Active Directory authentication. For more information, see Using gMSAs for Windows Containers and Using gMSAs for Linux Containers in the Amazon Elastic Container Service Developer Guide.

This parameter maps to SecurityOpt in the docker container create command and the --security-opt option to docker run.

Valid values: "no-new-privileges" | "apparmor:PROFILE" | "label:value" | "credentialspec:CredentialSpecFilePath"

Gets and sets the property EntryPoint.

Early versions of the Amazon ECS container agent don't 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's passed to the container. This parameter maps to Entrypoint in the docker container create command and the --entrypoint option to docker run.

Gets and sets the property Environment.

The environment variables to pass to a container. This parameter maps to Env in the docker container create command and the --env option to docker run.

Gets and sets the property EnvironmentFiles.

A list of files containing the environment variables to pass to a container. This parameter maps to the --env-file option to docker run.

You can specify up to ten environment files. The file must have a .env file extension. Each line in an environment file contains an environment variable in VARIABLE=VALUE format. Lines beginning with # are treated as comments and are ignored.

If there are environment variables specified using the environment parameter in a container definition, they take precedence over the variables contained within an environment file. If multiple environment files are specified that contain the same variable, they're processed from the top down. We recommend that you use unique variable names. For more information, see Specifying Environment Variables in the Amazon Elastic Container Service Developer Guide.

Gets and sets the property Essential.

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, its failure doesn't 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's composed of multiple containers, 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.

Gets and sets the property ExtraHosts.

A list of hostnames and IP address mappings to append to the /etc/hosts file on the container. This parameter maps to ExtraHosts in the docker container create command and the --add-host option to docker run.

Gets and sets the property FirelensConfiguration.

The FireLens configuration for the container. This is used to specify and configure a log router for container logs. For more information, see Custom Log Routing in the Amazon Elastic Container Service Developer Guide.

Gets and sets the property HealthCheck.

The container health check command and associated configuration parameters for the container. This parameter maps to HealthCheck in the docker container create command and the HEALTHCHECK parameter of docker run.

Gets and sets the property Hostname.

The hostname to use for your container. This parameter maps to Hostname in the docker container create command and the --hostname option to docker run.

Gets and sets the property Image.

The image used to start a container. This string is passed directly to the Docker daemon. By default, images in the Docker Hub registry are available. Other repositories are specified with either repository-url/image:tag or repository-url/image@digest. For images using tags (repository-url/image:tag), up to 255 characters total are allowed, including letters (uppercase and lowercase), numbers, hyphens, underscores, colons, periods, forward slashes, and number signs (#). For images using digests (repository-url/image@digest), the 255 character limit applies only to the repository URL and image name (everything before the @ sign). The only supported hash function is sha256, and the hash value after sha256: must be exactly 64 characters (only letters A-F, a-f, and numbers 0-9 are allowed). This parameter maps to Image in the docker container create command and the IMAGE parameter of docker run.

• When a new task starts, the Amazon ECS container agent pulls the latest version of the specified image and tag for the container to use. However, subsequent updates to a repository image aren't propagated to already running tasks.

• 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..amazonaws.com/:latest or 012345678910.dkr.ecr..amazonaws.com/@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).

Gets and sets the property Interactive.

When this parameter is true, you can deploy containerized applications that require stdin or a tty to be allocated. This parameter maps to OpenStdin in the docker container create command and the --interactive option to docker run.

Gets and sets the property Links.

The links parameter allows containers to communicate with each other without the need for port mappings. This parameter is only supported if the network mode of a task definition is bridge. The name:internalName construct is analogous to name:alias in Docker links. Up to 255 letters (uppercase and lowercase), numbers, underscores, and hyphens are allowed.. This parameter maps to Links in the docker container create command and the --link option to docker run.

Gets and sets the property LinuxParameters.

Linux-specific modifications that are applied to the default Docker container configuration, such as Linux kernel capabilities. For more information see KernelCapabilities.

Gets and sets the property LogConfiguration.

The log configuration specification for the container.

This parameter maps to LogConfig in the docker container create command and the --log-driver option to docker run. By default, containers use the same logging driver that the Docker daemon uses. However the container can 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).

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 --format '{{.Server.APIVersion}}'

Gets and sets the property Memory.

The amount (in MiB) of memory to present to the container. If your container attempts to exceed the memory specified here, the container is killed. The total amount of memory reserved for all containers within a task must be lower than the task memory value, if one is specified. This parameter maps to Memory in the docker container create command and the --memory option to docker run.

If using the Fargate launch type, this parameter is optional.

If using the EC2 launch type, you must specify either a task-level memory value or a container-level memory value. If you specify both a container-level memory and memoryReservation value, memory must be greater than memoryReservation. If you specify memoryReservation, then that value is subtracted from the available memory resources for the container instance where the container is placed. Otherwise, the value of memory is used.

The Docker 20.10.0 or later daemon reserves a minimum of 6 MiB of memory for a container. So, don't specify less than 6 MiB of memory for your containers.

The Docker 19.03.13-ce or earlier daemon reserves a minimum of 4 MiB of memory for a container. So, don't specify less than 4 MiB of memory for your containers.

Gets and sets the property MemoryReservation.

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 docker container create command and the --memory-reservation option to docker run.

If a task-level memory value is not specified, you must specify a non-zero integer for one or both of memory or memoryReservation in a container definition. 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 where 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.

The Docker 20.10.0 or later daemon reserves a minimum of 6 MiB of memory for a container. So, don't specify less than 6 MiB of memory for your containers.

The Docker 19.03.13-ce or earlier daemon reserves a minimum of 4 MiB of memory for a container. So, don't specify less than 4 MiB of memory for your containers.

Gets and sets the property MountPoints.

The mount points for data volumes in your container.

This parameter maps to Volumes in the docker container create command and the --volume option to docker run.

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

Gets and sets the property Name.

The name of a container. If you're 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, underscores, and hyphens are allowed. This parameter maps to name in the docker container create command and the --name option to docker run.

Gets and sets the property PortMappings.

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, 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's no loopback for port mappings on Windows, so you can't access a container's mapped port from the host itself.

This parameter maps to PortBindings in the docker container create command 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.

Gets and sets the property Privileged.

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 docker container create command and the --privileged option to docker run

Gets and sets the property PseudoTerminal.

When this parameter is true, a TTY is allocated. This parameter maps to Tty in the docker container create command and the --tty option to docker run.

Gets and sets the property ReadonlyRootFilesystem.

When this parameter is true, the container is given read-only access to its root file system. This parameter maps to ReadonlyRootfs in the docker container create command and the --read-only option to docker run.

Gets and sets the property RepositoryCredentials.

The private repository authentication credentials to use.

Gets and sets the property ResourceRequirements.

The type and amount of a resource to assign to a container. The only supported resource is a GPU.

Gets and sets the property RestartPolicy.

The restart policy for a container. When you set up a restart policy, Amazon ECS can restart the container without needing to replace the task. For more information, see Restart individual containers in Amazon ECS tasks with container restart policies in the Amazon Elastic Container Service Developer Guide.

Gets and sets the property Secrets.

The secrets to pass to the container. For more information, see Specifying Sensitive Data in the Amazon Elastic Container Service Developer Guide.

Gets and sets the property StartTimeout.

Time duration (in seconds) to wait before giving up on resolving dependencies for a container. For example, you specify two containers in a task definition with containerA having a dependency on containerB reaching a COMPLETE, SUCCESS, or HEALTHY status. If a startTimeout value is specified for containerB and it doesn't reach the desired status within that time then containerA gives up and not start. This results in the task transitioning to a STOPPED state.

For tasks using the Fargate launch type, the task or service requires the following platforms:

• Linux platform version 1.3.0 or later.

• Windows platform version 1.0.0 or later.

For tasks using the EC2 launch type, your container instances require at least version 1.26.0 of the container agent to use a container start timeout value. However, we recommend using the latest container agent version. For information about checking your agent version and updating to the latest version, see Updating the Amazon ECS Container Agent in the Amazon Elastic Container Service Developer Guide. If you're using an Amazon ECS-optimized Linux AMI, your instance needs at least version 1.26.0-1 of the ecs-init package. If your container instances are launched from version 20190301 or later, then they contain the required versions of the container agent and ecs-init. For more information, see Amazon ECS-optimized Linux AMI in the Amazon Elastic Container Service Developer Guide.

The valid values for Fargate are 2-120 seconds.

Gets and sets the property StopTimeout.

Time duration (in seconds) to wait before the container is forcefully killed if it doesn't exit normally on its own.

For tasks using the Fargate launch type, the task or service requires the following platforms:

• Linux platform version 1.3.0 or later.

• Windows platform version 1.0.0 or later.

For tasks that use the Fargate launch type, the max stop timeout value is 120 seconds and if the parameter is not specified, the default value of 30 seconds is used.

For tasks that use the EC2 launch type, if the stopTimeout parameter isn't specified, the value set for the Amazon ECS container agent configuration variable ECS_CONTAINER_STOP_TIMEOUT is used. If neither the stopTimeout parameter or the ECS_CONTAINER_STOP_TIMEOUT agent configuration variable are set, then the default values of 30 seconds for Linux containers and 30 seconds on Windows containers are used. Your container instances require at least version 1.26.0 of the container agent to use a container stop timeout value. However, we recommend using the latest container agent version. For information about checking your agent version and updating to the latest version, see Updating the Amazon ECS Container Agent in the Amazon Elastic Container Service Developer Guide. If you're using an Amazon ECS-optimized Linux AMI, your instance needs at least version 1.26.0-1 of the ecs-init package. If your container instances are launched from version 20190301 or later, then they contain the required versions of the container agent and ecs-init. For more information, see Amazon ECS-optimized Linux AMI in the Amazon Elastic Container Service Developer Guide.

The valid values for Fargate are 2-120 seconds.

Gets and sets the property SystemControls.

A list of namespaced kernel parameters to set in the container. This parameter maps to Sysctls in the docker container create command and the --sysctl option to docker run. For example, you can configure net.ipv4.tcp_keepalive_time setting to maintain longer lived connections.

Gets and sets the property Ulimits.

A list of ulimits to set in the container. If a ulimit value is specified in a task definition, it overrides the default values set by Docker. This parameter maps to Ulimits in the docker container create command and the --ulimit option to docker run. Valid naming values are displayed in the Ulimit data type.

Amazon ECS tasks hosted on Fargate use the default resource limit values set by the operating system with the exception of the nofile resource limit parameter which Fargate overrides. The nofile resource limit sets a restriction on the number of open files that a container can use. The default nofile soft limit is 65535 and the default hard limit is 65535.

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 --format '{{.Server.APIVersion}}'

Gets and sets the property User.

The user to use inside the container. This parameter maps to User in the docker container create command and the --user option to docker run.

You can specify the user using the following formats. If specifying a UID or GID, you must specify it as a positive integer.

• user

• user:group

• uid

• uid:gid

• user:gid

• uid:group

Gets and sets the property VersionConsistency.

Specifies whether Amazon ECS will resolve the container image tag provided in the container definition to an image digest. By default, the value is enabled. If you set the value for a container as disabled, Amazon ECS will not resolve the provided container image tag to a digest and will use the original image URI specified in the container definition for deployment. For more information about container image resolution, see Container image resolution in the Amazon ECS Developer Guide.

Gets and sets the property VolumesFrom.

Data volumes to mount from another container. This parameter maps to VolumesFrom in the docker container create command and the --volumes-from option to docker run.

Gets and sets the property WorkingDirectory.

The working directory to run commands inside the container in. This parameter maps to WorkingDir in the docker container create command and the --workdir option to docker run.