Amazon ECS Container Agent

The Amazon ECS Container Agent is software developed for the Amazon EC2 Container Service.

It runs on Container Instances and starts containers on behalf of Amazon ECS.

Usage

The best source of information on running this software is the AWS Documentation.

On the Amazon Linux AMI

On the Amazon Linux AMI, we provide an init package 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 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.

Note: The below command should work on most AMIs, but the cgroup and execdriver path may differ in some cases

$ mkdir -p /var/log/ecs /etc/ecs /var/lib/ecs/data
$ touch /etc/ecs/ecs.config
$ docker run --name ecs-agent \
    --restart on-failure:10 -d \
    -v /var/run/docker.sock:/var/run/docker.sock \
    -v /var/log/ecs:/log \
    -v /var/lib/ecs/data:/data \
    -v /var/lib/docker:/var/lib/docker \
    -v /sys/fs/cgroup:/sys/fs/cgroup:ro \
    -v /var/run/docker/execdriver/native:/var/lib/docker/execdriver/native:ro \
    -p 127.0.0.1:51678:51678 \
    --env-file /etc/ecs/ecs.config \
    -e ECS_LOGFILE=/log/ecs-agent.log \
    -e ECS_DATADIR=/data/ \
    amazon/amazon-ecs-agent

See also the Advanced Usage section below.

Building and Running from source

Please note, running the Amazon ECS Container Agent outside of Amazon EC2 is not supported

Docker Image

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

This will produce an image tagged amazon/ecs-container-agent:make which you may run as described above.

Standalone

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

The following commands will run it outside of Docker:

make gobuild
./out/amazon-ecs-agent

Make Targets

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

Make Target	Description
release	(Default) release builds the agent within a docker container and and packages it into a scratch-based image
gobuild	gobuild runs a normal go build of the agent and stores the binary in ./out/amazon-ecs-agent
static	static runs go build to produce a static binary in ./out/amazon-ecs-agent
test	test runs all tests using go test
test-in-docker	test-in-docker runs all tests inside a docker container
clean	clean removes build artifacts. Note: this does not remove docker images

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 following environment variables are available. All of them are optional. They are listed in a general order of likelihood that a user may want to configure them as something other than the defaults.

Environment Key	Example Value(s)	Description	Default Value
ECS_CLUSTER	clusterName	The cluster this agent should check into.	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]
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"	What type of auth data is stored in the ECS_ENGINE_AUTH_DATA key
ECS_ENGINE_AUTH_DATA	See 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 EC2 Instance Metadata
AWS_ACCESS_KEY_ID	AKIDEXAMPLE	The Access Key used by the agent for all calls.	Taken from EC2 Instance Metadata
AWS_SECRET_ACCESS_KEY	EXAMPLEKEY	The Secret Key used by the agent for all calls.	Taken from 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
ECS_LOGLEVEL	<crit> | <error> | <warn> | <info> | <debug>	What level to log at on stdout.	info
ECS_LOGFILE	/ecs-agent.log	The path to output full debugging info to. If blank, no logs will be written to file. If set, logs at debug level (regardless of ECS_LOGLEVEL) will be written to that file.	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
ECS_DATADIR	/data/	The container path where state is checkpointed for use across agent restarts.	/data/
ECS_UPDATES_ENABLED	<true | false>	Whether to exit for an updater to apply updates when requested	false
ECS_UPDATE_DOWNLOAD_DIR	/cache	Where to place update tarballs within the container
ECS_DISABLE_METRICS	<true | false>	Whether to disable metrics gathering for tasks.	false
ECS_DOCKER_GRAPHPATH	/var/lib/docker	Used to create the path to the state file of containers launched. The state file is used to read utilization metrics of containers.	/var/lib/docker
AWS_SESSION_TOKEN		The Session Token used for temporary credentials.	Taken from EC2 Instance Metadata
ECS_RESERVED_MEMORY	32	Memory, in MB, to reserve for use by things other than containers managed by ECS.	0
ECS_AVAILABLE_LOGGING_DRIVERS	["json-file","syslog"]	Which logging drivers are available on the Container Instance.	["json-file"]
ECS_DISABLE_PRIVILEGED	true	Whether launching privileged containers is disabled on the Container Instance.	false
ECS_SELINUX_CAPABLE	true	Whether SELinux is available on the Container Instance.	false
ECS_APPARMOR_CAPABLE	true	Whether AppArmor is available on the Container Instance.	false

Persistence

When running 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 Amazon ECS Agent will register a new Container Instance ARN on each launch and will not be able to update the state of tasks it previously ran.

Flags

The agent also supports the following flags:

• -k — The agent will not requre valid SSL certificates for the services it communicates with.
• -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.

Contributing

Contributions and feedback are welcome! Proposals and Pull Requests will be considered and responded to. Please see the CONTRIBUTING.md file for more information.

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

License

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