Amazon ECS Container Agent

The Amazon ECS Container Agent is a component of Amazon Elastic Container Service (Amazon ECS) and is responsible for managing containers on behalf of Amazon ECS.

Usage

The best source of information on running this software is the Amazon ECS documentation.

Please note that from Agent version 1.20.0, Minimum required Docker version is 1.9.0, corresponding to Docker API version 1.21. For more information, please visit Amazon ECS Container Agent Versions.

On the Amazon Linux AMI

On the Amazon Linux AMI, we provide an installable RPM which can be used via sudo yum install ecs-init && sudo start ecs. This is the recommended way to run it in this environment.

On Other Linux AMIs

The Amazon ECS Container Agent may also be run in a Docker container on an EC2 instance with a recent Docker version installed. A Docker image is available in our Docker Hub Repository.

$ # Set up directories the agent uses
$ mkdir -p /var/log/ecs /etc/ecs /var/lib/ecs/data
$ touch /etc/ecs/ecs.config
$ # Set up necessary rules to enable IAM roles for tasks
$ sysctl -w net.ipv4.conf.all.route_localnet=1
$ iptables -t nat -A PREROUTING -p tcp -d 169.254.170.2 --dport 80 -j DNAT --to-destination 127.0.0.1:51679
$ iptables -t nat -A OUTPUT -d 169.254.170.2 -p tcp -m tcp --dport 80 -j REDIRECT --to-ports 51679
$ # Run the agent
$ docker run --name ecs-agent \
    --detach=true \
    --restart=on-failure:10 \
    --volume=/var/run/docker.sock:/var/run/docker.sock \
    --volume=/var/log/ecs:/log \
    --volume=/var/lib/ecs/data:/data \
    --net=host \
    --env-file=/etc/ecs/ecs.config \
    --env=ECS_LOGFILE=/log/ecs-agent.log \
    --env=ECS_DATADIR=/data/ \
    --env=ECS_ENABLE_TASK_IAM_ROLE=true \
    --env=ECS_ENABLE_TASK_IAM_ROLE_NETWORK_HOST=true \
    amazon/amazon-ecs-agent:latest

On Other Linux AMIs when awsvpc networking mode is enabled

For the AWS VPC networking mode, ECS agent requires CNI plugin and dhclient to be available. ECS also needs the ecs-init to run as part of its startup. The following is an example of docker run configuration for running ecs-agent with Task ENI enabled. Note that ECS agent currently only supports cgroupfs for cgroup driver.

$ # Run the agent
$ /usr/bin/docker run --name ecs-agent \
--init \
--restart=on-failure:10 \
--volume=/var/run:/var/run \
--volume=/var/log/ecs/:/log:Z \
--volume=/var/lib/ecs/data:/data:Z \
--volume=/etc/ecs:/etc/ecs \
--volume=/sbin:/host/sbin \
--volume=/lib:/lib \
--volume=/lib64:/lib64 \
--volume=/usr/lib:/usr/lib \
--volume=/usr/lib64:/usr/lib64 \
--volume=/proc:/host/proc \
--volume=/sys/fs/cgroup:/sys/fs/cgroup \
--net=host \
--env-file=/etc/ecs/ecs.config \
--cap-add=sys_admin \
--cap-add=net_admin \
--env ECS_ENABLE_TASK_ENI=true \
--env ECS_UPDATES_ENABLED=true \
--env ECS_ENGINE_TASK_CLEANUP_WAIT_DURATION=1h \
--env ECS_DATADIR=/data \
--env ECS_ENABLE_TASK_IAM_ROLE=true \
--env ECS_ENABLE_TASK_IAM_ROLE_NETWORK_HOST=true \
--env ECS_LOGFILE=/log/ecs-agent.log \
--env ECS_AVAILABLE_LOGGING_DRIVERS='["json-file","awslogs","syslog","none"]' \
--env ECS_LOGLEVEL=info \
--detach \
amazon/amazon-ecs-agent:latest

See also the Advanced Usage section below.

On the ECS Optimized Windows AMI

ECS Optimized Windows AMI ships with a pre-installed PowerShell module called ECSTools to install, configure, and run the ECS Agent as a Windows service. To install the service, you can run the following PowerShell commands on an EC2 instance. To launch into another cluster instead of windows, replace the 'windows' in the script below with the name of your cluster.

PS C:\> Import-Module ECSTools
PS C:\> # The -EnableTaskIAMRole option is required to enable IAM roles for tasks.
PS C:\> Initialize-ECSAgent -Cluster 'windows' -EnableTaskIAMRole

Downloading Different Version of ECS Agent

To download different version of ECS Agent, you can do the following:

PS C:\> # use agentVersion = "latest" for the latest available agent version
PS C:\> $agentVersion = "v1.20.4"
PS C:\> Initialize-ECSAgent -Cluster 'windows' -EnableTaskIAMRole -Version $agentVersion

Advanced Usage

The Amazon ECS Container Agent supports a number of configuration options, most of which should be set through environment variables.

Environment Variables

The table below provides an overview of optional environment variables that can be used to configure the ECS agent. See the Amazon ECS developer guide for additional details on each available environment variable.

Environment Key	Example Value(s)	Description	Default value on Linux	Default value on Windows
`ECS_CLUSTER`	clusterName	The cluster this agent should check into.	default	default
`ECS_RESERVED_PORTS`	`[22, 80, 5000, 8080]`	An array of ports that should be marked as unavailable for scheduling on this container instance.	`[22, 2375, 2376, 51678, 51679]`	`[53, 135, 139, 445, 2375, 2376, 3389, 5985, 5986, 51678, 51679]`
`ECS_RESERVED_PORTS_UDP`	`[53, 123]`	An array of UDP ports that should be marked as unavailable for scheduling on this container instance.	`[]`	`[]`
`ECS_ENGINE_AUTH_TYPE`	"docker" \| "dockercfg"	The type of auth data that is stored in the `ECS_ENGINE_AUTH_DATA` key.
`ECS_ENGINE_AUTH_DATA`	See the dockerauth documentation	Docker auth data formatted as defined by `ECS_ENGINE_AUTH_TYPE`.
`AWS_DEFAULT_REGION`	<us-west-2>\|<us-east-1>\|…	The region to be used in API requests as well as to infer the correct backend host.	Taken from Amazon EC2 instance metadata.	Taken from Amazon EC2 instance metadata.
`AWS_ACCESS_KEY_ID`	AKIDEXAMPLE	The access key used by the agent for all calls.	Taken from Amazon EC2 instance metadata.	Taken from Amazon EC2 instance metadata.
`AWS_SECRET_ACCESS_KEY`	EXAMPLEKEY	The secret key used by the agent for all calls.	Taken from Amazon EC2 instance metadata.	Taken from Amazon EC2 instance metadata.
`AWS_SESSION_TOKEN`		The session token used for temporary credentials.	Taken from Amazon EC2 instance metadata.	Taken from Amazon EC2 instance metadata.
`DOCKER_HOST`	`unix:///var/run/docker.sock`	Used to create a connection to the Docker daemon; behaves similarly to this environment variable as used by the Docker client.	`unix:///var/run/docker.sock`	`npipe:////./pipe/docker_engine`
`ECS_LOGLEVEL`	<crit> \| <error> \| <warn> \| <info> \| <debug>	The level of detail to be logged.	info	info
`ECS_LOGLEVEL_ON_INSTANCE`	<none> \| <crit> \| <error> \| <warn> \| <info> \| <debug>	Can be used to override `ECS_LOGLEVEL` and set a level of detail that should be logged in the on-instance log file, separate from the level that is logged in the logging driver. If a logging driver is explicitly set, on-instance logs are turned off by default, but can be turned back on with this variable.	none if `ECS_LOG_DRIVER` is explicitly set to a non-empty value; otherwise the same value as `ECS_LOGLEVEL`	none if `ECS_LOG_DRIVER` is explicitly set to a non-empty value; otherwise the same value as `ECS_LOGLEVEL`
`ECS_LOGFILE`	/ecs-agent.log	The location where logs should be written. Log level is controlled by `ECS_LOGLEVEL`.	blank	blank
`ECS_CHECKPOINT`	<true \| false>	Whether to checkpoint state to the DATADIR specified below.	true if `ECS_DATADIR` is explicitly set to a non-empty value; false otherwise	true if `ECS_DATADIR` is explicitly set to a non-empty value; false otherwise
`ECS_DATADIR`	/data/	The container path where state is checkpointed for use across agent restarts. Note that on Linux, when you specify this, you will need to make sure that the Agent container has a bind mount of `$ECS_HOST_DATA_DIR/data:$ECS_DATADIR` with the corresponding values of `ECS_HOST_DATA_DIR` and `ECS_DATADIR`.	/data/	`C:\ProgramData\Amazon\ECS\data`
`ECS_UPDATES_ENABLED`	<true \| false>	Whether to exit for an updater to apply updates when requested.	false	false
`ECS_DISABLE_METRICS`	<true \| false>	Whether to disable metrics gathering for tasks.	false	true
`ECS_POLL_METRICS`	<true \| false>	Whether to poll or stream when gathering metrics for tasks. This defaulted to `false` previous to agent version 1.40.0. WARNING: setting this to false on an instance with many containers can result in very high CPU utilization by the agent, dockerd, and containerd.	`true`	`true`
`ECS_POLLING_METRICS_WAIT_DURATION`	10s	Time to wait between polling for metrics for a task. Not used when ECS_POLL_METRICS is false. Maximum value is 20s and minimum value is 5s. If user sets above maximum it will be set to max, and if below minimum it will be set to min.	10s	10s
`ECS_RESERVED_MEMORY`	32	Memory, in MiB, to reserve for use by things other than containers managed by Amazon ECS.	0	0
`ECS_AVAILABLE_LOGGING_DRIVERS`	`["awslogs","fluentd","gelf","json-file","journald","logentries","splunk","syslog"]`	Which logging drivers are available on the container instance.	`["json-file","none"]`	`["json-file","none"]`
`ECS_DISABLE_PRIVILEGED`	`true`	Whether launching privileged containers is disabled on the container instance.	`false`	`false`
`ECS_SELINUX_CAPABLE`	`true`	Whether SELinux is available on the container instance.	`false`	`false`
`ECS_APPARMOR_CAPABLE`	`true`	Whether AppArmor is available on the container instance.	`false`	`false`
`ECS_ENGINE_TASK_CLEANUP_WAIT_DURATION`	10m	Time to wait to delete containers for a stopped task. If set to less than 1 minute, the value is ignored.	3h	3h
`ECS_CONTAINER_STOP_TIMEOUT`	10m	Instance scoped configuration for time to wait for the container to exit normally before being forcibly killed.	30s	30s
`ECS_CONTAINER_START_TIMEOUT`	10m	Timeout before giving up on starting a container.	3m	8m
`ECS_ENABLE_TASK_IAM_ROLE`	`true`	Whether to enable IAM Roles for Tasks on the Container Instance	`false`	`false`
`ECS_ENABLE_TASK_IAM_ROLE_NETWORK_HOST`	`true`	Whether to enable IAM Roles for Tasks when launched with `host` network mode on the Container Instance	`false`	`false`
`ECS_DISABLE_IMAGE_CLEANUP`	`true`	Whether to disable automated image cleanup for the ECS Agent.	`false`	`false`
`ECS_IMAGE_CLEANUP_INTERVAL`	30m	The time interval between automated image cleanup cycles. If set to less than 10 minutes, the value is ignored.	30m	30m
`ECS_IMAGE_MINIMUM_CLEANUP_AGE`	30m	The minimum time interval between when an image is pulled and when it can be considered for automated image cleanup.	1h	1h
`NON_ECS_IMAGE_MINIMUM_CLEANUP_AGE`	30m	The minimum time interval between when a non ECS image is created and when it can be considered for automated image cleanup.	1h	1h
`ECS_NUM_IMAGES_DELETE_PER_CYCLE`	5	The maximum number of images to delete in a single automated image cleanup cycle. If set to less than 1, the value is ignored.	5	5
`ECS_IMAGE_PULL_BEHAVIOR`	<default \| always \| once \| prefer-cached >	The behavior used to customize the pull image process. If `default` is specified, the image will be pulled remotely, if the pull fails then the cached image in the instance will be used. If `always` is specified, the image will be pulled remotely, if the pull fails then the task will fail. If `once` is specified, the image will be pulled remotely if it has not been pulled before or if the image was removed by image cleanup, otherwise the cached image in the instance will be used. If `prefer-cached` is specified, the image will be pulled remotely if there is no cached image, otherwise the cached image in the instance will be used.	default	default
`ECS_IMAGE_PULL_INACTIVITY_TIMEOUT`	1m	The time to wait after docker pulls complete waiting for extraction of a container. Useful for tuning large Windows containers.	1m	3m
`ECS_IMAGE_PULL_TIMEOUT`	1h	The time to wait for pulling docker image.	2h	2h
`ECS_INSTANCE_ATTRIBUTES`	`{"stack": "prod"}`	These attributes take effect only during initial registration. After the agent has joined an ECS cluster, use the PutAttributes API action to add additional attributes. For more information, see Amazon ECS Container Agent Configuration in the Amazon ECS Developer Guide.	`{}`	`{}`
`ECS_ENABLE_TASK_ENI`	`false`	Whether to enable task networking for task to be launched with its own network interface	`false`	Not applicable
`ECS_ENABLE_HIGH_DENSITY_ENI`	`false`	Whether to enable high density eni feature when using task networking	`true`	Not applicable
`ECS_CNI_PLUGINS_PATH`	`/ecs/cni`	The path where the cni binary file is located	`/amazon-ecs-cni-plugins`	Not applicable
`ECS_AWSVPC_BLOCK_IMDS`	`true`	Whether to block access to Instance Metadata for Tasks started with `awsvpc` network mode	`false`	Not applicable
`ECS_AWSVPC_ADDITIONAL_LOCAL_ROUTES`	`["10.0.15.0/24"]`	In `awsvpc` network mode, traffic to these prefixes will be routed via the host bridge instead of the task ENI	`[]`	Not applicable
`ECS_ENABLE_CONTAINER_METADATA`	`true`	When `true`, the agent will create a file describing the container's metadata and the file can be located and consumed by using the container enviornment variable `$ECS_CONTAINER_METADATA_FILE`	`false`	`false`
`ECS_HOST_DATA_DIR`	`/var/lib/ecs`	The source directory on the host from which ECS_DATADIR is mounted. We use this to determine the source mount path for container metadata files in the case the ECS Agent is running as a container. We do not use this value in Windows because the ECS Agent is not running as container in Windows. On Linux, note that when you specify this, you will need to make sure that the Agent container has a bind mount of `$ECS_HOST_DATA_DIR/data:$ECS_DATADIR` with the corresponding values of `ECS_HOST_DATA_DIR` and `ECS_DATADIR`.	`/var/lib/ecs`	`Not used`
`ECS_ENABLE_TASK_CPU_MEM_LIMIT`	`true`	Whether to enable task-level cpu and memory limits	`true`	`false`
`ECS_CGROUP_PATH`	`/sys/fs/cgroup`	The root cgroup path that is expected by the ECS agent. This is the path that accessible from the agent mount.	`/sys/fs/cgroup`	Not applicable
`ECS_CGROUP_CPU_PERIOD`	`10ms`	CGroups CPU period for task level limits. This value should be between 8ms to 100ms	`100ms`	Not applicable
`ECS_ENABLE_CPU_UNBOUNDED_WINDOWS_WORKAROUND`	`true`	When `true`, ECS will allow CPU unbounded(CPU=`0`) tasks to run along with CPU bounded tasks in Windows.	Not applicable	`false`
`ECS_ENABLE_MEMORY_UNBOUNDED_WINDOWS_WORKAROUND`	`true`	When `true`, ECS will ignore the memory reservation parameter (soft limit) to run along with memory bounded tasks in Windows. To run a memory unbounded task, omit the memory hard limit and set any memory reservation, it will be ignored.	Not applicable	`false`
`ECS_TASK_METADATA_RPS_LIMIT`	`100,150`	Comma separated integer values for steady state and burst throttle limits for task metadata endpoint	`40,60`	`40,60`
`ECS_SHARED_VOLUME_MATCH_FULL_CONFIG`	`true`	When `true`, ECS Agent will compare name, driver options, and labels to make sure volumes are identical. When `false`, Agent will short circuit shared volume comparison if the names match. This is the default Docker behavior. If a volume is shared across instances, this should be set to `false`.	`false`	`false`
`ECS_CONTAINER_INSTANCE_PROPAGATE_TAGS_FROM`	`ec2_instance`	If `ec2_instance` is specified, existing tags defined on the container instance will be registered to Amazon ECS and will be discoverable using the `ListTagsForResource` API. Using this requires that the IAM role associated with the container instance have the `ec2:DescribeTags` action allowed.	`none`	`none`
`ECS_CONTAINER_INSTANCE_TAGS`	`{"tag_key": "tag_val"}`	The metadata that you apply to the container instance to help you categorize and organize them. Each tag consists of a key and an optional value, both of which you define. Tag keys can have a maximum character length of 128 characters, and tag values can have a maximum length of 256 characters. If tags also exist on your container instance that are propagated using the `ECS_CONTAINER_INSTANCE_PROPAGATE_TAGS_FROM` parameter, those tags will be overwritten by the tags specified using `ECS_CONTAINER_INSTANCE_TAGS`.	`{}`	`{}`
`ECS_ENABLE_UNTRACKED_IMAGE_CLEANUP`	`true`	Whether to allow the ECS agent to delete containers and images that are not part of ECS tasks.	`false`	`false`
`ECS_EXCLUDE_UNTRACKED_IMAGE`	`alpine:latest`	Comma seperated list of `imageName:tag` of images that should not be deleted by the ECS agent if `ECS_ENABLE_UNTRACKED_IMAGE_CLEANUP` is enabled.
`ECS_DISABLE_DOCKER_HEALTH_CHECK`	`false`	Whether to disable the Docker Container health check for the ECS Agent.	`false`	`false`
`ECS_NVIDIA_RUNTIME`	nvidia	The Nvidia Runtime to be used to pass Nvidia GPU devices to containers.	nvidia	Not Applicable
`ECS_ENABLE_SPOT_INSTANCE_DRAINING`	`true`	Whether to enable Spot Instance draining for the container instance. If true, if the container instance receives a spot interruption notice, agent will set the instance's status to DRAINING, which gracefully shuts down and replaces all tasks running on the instance that are part of a service. It is recommended that this be set to `true` when using spot instances.	`false`	`false`
`ECS_LOG_ROLLOVER_TYPE`	`size` \| `hourly`	Determines whether the container agent logfile will be rotated based on size or hourly. By default, the agent logfile is rotated each hour.	`hourly`	`hourly`
`ECS_LOG_OUTPUT_FORMAT`	`logfmt` \| `json`	Determines the log output format. When the json format is used, each line in the log would be a structured JSON map.	`logfmt`	`logfmt`
`ECS_LOG_MAX_FILE_SIZE_MB`	`10`	When the ECS_LOG_ROLLOVER_TYPE variable is set to size, this variable determines the maximum size (in MB) the log file before it is rotated. If the rollover type is set to hourly then this variable is ignored.	`10`	`10`
`ECS_LOG_MAX_ROLL_COUNT`	`24`	Determines the number of rotated log files to keep. Older log files are deleted once this limit is reached.	`24`	`24`
`ECS_LOG_DRIVER`	`awslogs` \| `fluentd` \| `gelf` \| `json-file` \| `journald` \| `logentries` \| `syslog` \| `splunk`	The logging driver to be used by the Agent container.	`json-file`	Not applicable
`ECS_LOG_OPTS`	`{"option":"value"}`	The options for configuring the logging driver set in `ECS_LOG_DRIVER`.	`{}`	Not applicable
`ECS_ENABLE_AWSLOGS_EXECUTIONROLE_OVERRIDE`	`true`	Whether to enable awslogs log driver to authenticate via credentials of task execution IAM role. Needs to be true if you want to use awslogs log driver in a task that has task execution IAM role specified. When using the ecs-init RPM with version equal or later than V1.16.0-1, this env is set to true by default.	`false`	`false`

Persistence

When you run the Amazon ECS Container Agent in production, its datadir should be persisted between runs of the Docker container. If this data is not persisted, the agent registers a new container instance ARN on each launch and is not able to update the state of tasks it previously ran.

Flags

The agent also supports the following flags:

-k — The agent will not require valid SSL certificates for the services that it communicates with. We recommend against using this flag.
-loglevel — Options: [<crit>|<error>|<warn>|<info>|<debug>]. The agent will output on stdout at the given level. This is overridden by the ECS_LOGLEVEL environment variable, if present.

Building and Running from Source

Running the Amazon ECS Container Agent outside of Amazon EC2 is not supported.

Docker Image (on Linux)

The Amazon ECS Container Agent may be built by typing make with the Docker daemon (v1.5.0) running.

This produces an image tagged amazon/ecs-container-agent:make that you may run as described above.

Standalone (on Linux)

The Amazon ECS Container Agent may also be run outside of a Docker container as a Go binary. This is not recommended for production on Linux, but it can be useful for development or easier integration with your local Go tools.

The following commands run the agent outside of Docker:

make gobuild
./out/amazon-ecs-agent

Make Targets (on Linux)

The following targets are available. Each may be run with make <target>.

Make Target	Description
`release`	(Default) Builds the agent within a Docker container and and packages it into a scratch-based image
`gobuild`	Runs a normal `go build` of the agent and stores the binary in `./out/amazon-ecs-agent`
`static`	Runs `go build` to produce a static binary in `./out/amazon-ecs-agent`
`test`	Runs all unit tests using `go test`
`test-in-docker`	Runs all tests inside a Docker container
`run-integ-tests`	Runs all integration tests in the `engine` and `stats` packages
`clean`	Removes build artifacts. Note: this does not remove Docker images

Standalone (on Windows)

The Amazon ECS Container Agent may be built by typing go build -o amazon-ecs-agent.exe ./agent.

Scripts (on Windows)

The following scripts are available to help develop the Amazon ECS Container Agent on Windows:

scripts\run-integ-tests.ps1 - Runs all integration tests in the engine and stats packages
misc\windows-deploy\Install-ECSAgent.ps1 - Install the ECS agent as a Windows service
misc\windows-deploy\amazon-ecs-agent.ps1 - Helper script to set up the host and run the agent as a process
misc\windows-deploy\user-data.ps1 - Sample user-data that can be used with the Windows Server 2016 with Containers AMI to run the agent as a process

Contributing

Contributions and feedback are welcome! Proposals and pull requests will be considered and responded to. For more information, see the CONTRIBUTING.md file.

If you have a bug/and issue around the behavior of the ECS agent, please open it here.

If you have a feature request, please open it over at the AWS Containers Roadmap.

Amazon Web Services does not currently provide support for modified copies of this software.

Security disclosures

If you think you’ve found a potential security issue, please do not post it in the Issues. Instead, please follow the instructions here or email AWS security directly.

License

The Amazon ECS Container Agent is licensed under the Apache 2.0 License.

efekarakus/amazon-ecs-agent