Amazon ECS on AWS Fargate
AWS Fargate is a technology that you can use with Amazon ECS to run containers
When you run your tasks and services with the Fargate launch type, you package your application in containers, specify the CPU and memory requirements, define networking and IAM policies, and launch the application. Each Fargate task has its own isolation boundary and does not share the underlying kernel, CPU resources, memory resources, or elastic network interface with another task.
Fargate offers platform versions for Amazon Linux 2 and Microsoft Windows 2019 Server Full and Core editions. Unless otherwise specified, the information on this page applies to all Fargate platforms.
This topic describes the different components of Fargate tasks and services, and calls out special considerations for using Fargate with Amazon ECS.
For information about the Regions that support Linux containers on Fargate, see Supported Regions for Linux containers on AWS Fargate.
For information about the Regions that support Windows containers on Fargate, see Supported Regions for Windows containers on AWS Fargate.
Task definitions
Amazon ECS tasks on AWS Fargate do not support all of the task definition parameters that are available. Some parameters are not supported at all, and others behave differently for Fargate tasks.
The following task definition parameters are not valid in Fargate tasks:
-
disableNetworking
-
dnsSearchDomains
-
dnsServers
-
dockerSecurityOptions
-
extraHosts
-
gpu
-
ipcMode
-
links
-
pidMode
-
placementConstraints
-
privileged
-
systemControls
-
maxSwap
-
swappiness
The following task definition parameters are valid in Fargate tasks, but have limitations that should be noted:
-
linuxParameters
– When specifying Linux-specific options that are applied to the container, forcapabilities
theadd
parameter is not supported. Thedevices
,sharedMemorySize
, andtmpfs
parameters are not supported. For more information, see Linux parameters. -
volumes
– Fargate tasks only support bind mount host volumes, so thedockerVolumeConfiguration
parameter is not supported. For more information, see Volumes. -
cpu
- For Windows containers on AWS Fargate, the value cannot be less than 1 vCPU.
To ensure that your task definition validates for use with Fargate, you can specify the following when you register the task definition:
-
In the AWS Management Console, for the Requires Compatibilities field, specify
FARGATE
. -
In the AWS CLI, specify the
--requires-compatibilities
option. -
In the Amazon ECS API, specify the
requiresCompatibilities
flag.
Network mode
Amazon ECS task definitions for AWS Fargate require that the network mode
is set to awsvpc
. The awsvpc
network mode provides each
task with its own elastic network interface. For more information, see AWS Fargate task networking in the
Amazon Elastic Container Service User Guide for AWS Fargate.
A network configuration is also required when creating a service or manually running tasks. For more information, see AWS Fargate task networking in the Amazon Elastic Container Service User Guide for AWS Fargate.
Task Operating Systems
When you configure a task and container definition for AWS Fargate, you must specify the Operating System that the container runs. The following Operating Systems are supported for AWS Fargate:
-
Amazon Linux 2
-
Windows Server 2019 Full
-
Windows Server 2019 Core
-
Windows Server 2022 Full
-
Windows Server 2022 Core
Task CPU architecture
There are 2 architectures available for the Amazon ECS task definition, ARM and X86_64.
When you run Windows containers on AWS Fargate, you must have the X86_64 CPU architecture.
When you run Linux containers on AWS Fargate, you can use the X86_64 CPU architecture, or the ARM64 architecture for your ARM-based applications. For more information, see Working with 64-bit ARM workloads on Amazon ECS.
Task CPU and memory
Amazon ECS task definitions for AWS Fargate require that you specify CPU and memory at the task level. Although you can also specify CPU and memory at the container level for Fargate tasks, this is optional. Most use cases are satisfied by only specifying these resources at the task level. The table below shows the valid combinations of task-level CPU and memory.
CPU value |
Memory value |
Operating systems supported for AWS Fargate |
---|---|---|
256 (.25 vCPU) |
512 MiB, 1 GB, 2 GB |
Linux |
512 (.5 vCPU) |
1 GB, 2 GB, 3 GB, 4 GB |
Linux |
1024 (1 vCPU) |
2 GB, 3 GB, 4 GB, 5 GB, 6 GB, 7 GB, 8 GB |
Linux, Windows |
2048 (2 vCPU) |
Between 4 GB and 16 GB in 1 GB increments |
Linux, Windows |
4096 (4 vCPU) |
Between 8 GB and 30 GB in 1 GB increments |
Linux, Windows |
8192 (8 vCPU) This option requires Linux platform |
Between 16 GB and 60 GB in 4 GB increments |
Linux |
16384 (16vCPU) This option requires Linux platform |
Between 32 GB and 120 GB in 8 GB increments |
Linux |
Task resource limits
Amazon ECS task definitions for Linux containers on AWS Fargate support
the ulimits
parameter to define the resource limits to set for a
container.
Amazon ECS task definitions for Windows on AWS Fargate do not support the
ulimits
parameter to define the resource limits to set for a
container.
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 1024
and hard limit
is 4096
.
The following is an example task definition snippet that shows how to define a
custom nofile
limit that has been doubled:
"ulimits": [
{
"name": "nofile",
"softLimit": 2048
,
"hardLimit": 8192
}
]
For more information on the other resource limits that can be adjusted, see Resource limits.
Logging
Amazon ECS task definitions for AWS Fargate support the
awslogs
, splunk
, and awsfirelens
log
drivers for the log configuration.
The awslogs
log driver configures your Fargate tasks to
send log information to Amazon CloudWatch Logs. The following shows a snippet of a task
definition where the awslogs
log driver is configured:
"logConfiguration": {
"logDriver": "awslogs",
"options": {
"awslogs-group" : "/ecs/fargate-task-definition",
"awslogs-region": "us-east-1",
"awslogs-stream-prefix": "ecs"
}
}
For more information about using the awslogs
log driver in a task
definition to send your container logs to CloudWatch Logs, see Using the awslogs log driver.
For more information about the awsfirelens
log driver in a task
definition, see Custom log routing.
For more information about using the splunk
log driver in a task
definition, see Example: splunk log
driver.
Amazon ECS task execution IAM role
There is an optional task execution IAM role that you can specify with Fargate to allow your Fargate tasks to make API calls to Amazon ECR. The API calls pull container images as well as calling CloudWatch to store container application logs. For more information, see Amazon ECS task execution IAM role.
Example Amazon Linux 2 task definition
The following is an example task definition that sets up a web server using the Fargate launch type with an Amazon Linux 2 operating system:
{ "containerDefinitions": [ { "command": [ "/bin/sh -c \"echo '<html> <head> <title>Amazon ECS Sample App</title> <style>body {margin-top: 40px; background-color: #333;} </style> </head><body> <div style=color:white;text-align:center> <h1>Amazon ECS Sample App</h1> <h2>Congratulations!</h2> <p>Your application is now running on a container in Amazon ECS.</p> </div></body></html>' > /usr/local/apache2/htdocs/index.html && httpd-foreground\"" ], "entryPoint": [ "sh", "-c" ], "essential": true, "image": "httpd:2.4", "logConfiguration": { "logDriver": "awslogs", "options": { "awslogs-group" : "/ecs/fargate-task-definition", "awslogs-region": "us-east-1", "awslogs-stream-prefix": "ecs" } }, "name": "sample-fargate-app", "portMappings": [ { "containerPort": 80, "hostPort": 80, "protocol": "tcp" } ] } ], "cpu": "256", "executionRoleArn": "arn:aws:iam::
012345678910
:role/ecsTaskExecutionRole", "family": "fargate-task-definition", "runtimePlatform": { "operatingSystemFamily": "LINUX" }, "memory": "512", "networkMode": "awsvpc", "requiresCompatibilities": [ "FARGATE" ] }
Example Windows task definition
The following is an example task definition that sets up a web server using the Fargate launch type with a Windows 2019 Server operating system.
{ "containerDefinitions": [ { "command": [ "New-Item -Path C:\\inetpub\\wwwroot\\index.html -Type file -Value '<html> <head> <title>Amazon ECS Sample App</title> <style>body {margin-top: 40px; background-color: #333;} </style> </head><body> <div style=color:white;text-align:center> <h1>Amazon ECS Sample App</h1> <h2>Congratulations!</h2> <p>Your application is now running on a container in Amazon ECS.</p>'; C:\\ServiceMonitor.exe w3svc" ], "entryPoint": [ "powershell", "-Command" ], "essential": true, "cpu": 2048, "memory": 4096, "image": "mcr.microsoft.com/windows/servercore/iis:windowsservercore-ltsc2019", "logConfiguration": { "logDriver": "awslogs", "options": { "awslogs-group": "/ecs/fargate-windows-task-definition", "awslogs-region": "us-east-1", "awslogs-stream-prefix": "ecs" } }, "name": "sample_windows_app", "portMappings": [ { "hostPort": 80, "containerPort": 80, "protocol": "tcp" } ] } ], "memory": "4096", "cpu": "2048", "networkMode": "awsvpc", "family": "windows-simple-iis-2019-core", "executionRoleArn": "arn:aws:iam::
012345678910
:role/ecsTaskExecutionRole", "runtimePlatform": { "operatingSystemFamily": "WINDOWS_SERVER_2019_CORE" }, "requiresCompatibilities": [ "FARGATE" ] }
Task storage
For Amazon ECS tasks hosted on Fargate, the following storage types are supported:
-
Amazon EFS volumes for persistent storage. For more information, see Amazon EFS volumes.
-
Bind mounts for ephemeral storage. For more information, see Bind mounts.
Tasks and services
After you have your Amazon ECS task definitions for AWS Fargate prepared, there are some decisions to make when creating your service.
Task networking
Amazon ECS tasks for AWS Fargate require the awsvpc
network
mode, which provides each task with an elastic network interface. When you run a
task or create a service with this network mode, you must specify one or more
subnets to attach the network interface and one or more security groups to apply to
the network interface.
If you are using public subnets, decide whether to provide a public IP address for the network interface. For a Fargate task in a public subnet to pull container images, a public IP address needs to be assigned to the task's elastic network interface, with a route to the internet or a NAT gateway that can route requests to the internet. For a Fargate task in a private subnet to pull container images, you need a NAT gateway in the subnet to route requests to the internet. When you host your container images in Amazon ECR, you can configure Amazon ECR to use an interface VPC endpoint. In this case, the task's private IPv4 address is used for the image pull. For more information about Amazon ECR interface endpoints, see Amazon ECR interface VPC endpoints (AWS PrivateLink) in the Amazon Elastic Container Registry User Guide.
The following is an example of the networkConfiguration section for a Fargate service:
"networkConfiguration": {
"awsvpcConfiguration": {
"assignPublicIp": "ENABLED",
"securityGroups": [ "sg-12345678
" ],
"subnets": [ "subnet-12345678
" ]
}
}
Service load balancing
Your Amazon ECS service on AWS Fargate can optionally be configured to use Elastic Load Balancing to distribute traffic evenly across the tasks in your service.
Amazon ECS services on AWS Fargate support the Application Load Balancer and Network Load Balancer load balancer types. Application Load Balancers are used to route HTTP/HTTPS (or layer 7) traffic. Network Load Balancers are used to route TCP or UDP (or layer 4) traffic. For more information, see Load balancer types.
When you create a target group for these services, you must choose ip
as the target type, not instance
. This is because tasks that use the
awsvpc
network mode are associated with an elastic network
interface, not an Amazon EC2 instance. For more information, see Service load balancing.
Using a Network Load Balancer to route UDP traffic to your Amazon ECS on AWS Fargate tasks is only supported when using platform version 1.4 or later.
Private registry authentication
Amazon ECS tasks for AWS Fargate can authenticate with private image registries, including Docker Hub, using basic authentication. When you enable private registry authentication, you can use private Docker images in your task definitions.
To use private registry authentication, you create a secret with AWS Secrets Manager containing
the credentials for your private registry. Then, within your container definition, you
specify repositoryCredentials
with the full ARN of the secret that you
created. The following snippet of a task definition shows the required
parameters:
"containerDefinitions": [
{
"image": "private-repo/private-image
",
"repositoryCredentials": {
"credentialsParameter: "arn:aws:secretsmanager:region
:aws_account_id
:secret:secret_name
"
}
}
]
For more information, see Private registry authentication for tasks.
Clusters
Clusters may contain tasks using both the Fargate and EC2 launch types. When viewing your clusters in the AWS Management Console, Fargate and EC2 task counts are displayed separately.
For more information about Amazon ECS clusters, including a walkthrough for creating a cluster, see Amazon ECS clusters.
Fargate Spot
Amazon ECS capacity providers enable you to use both AWS Fargate and Fargate Spot capacity with your Amazon ECS tasks.
Windows containers on AWS Fargate cannot use the Fargate Spot capacity provider.
With Fargate Spot you can run interruption tolerant Amazon ECS tasks at a discounted rate compared to the AWS Fargate price. Fargate Spot runs tasks on spare compute capacity. When AWS needs the capacity back, your tasks will be interrupted with a two-minute warning. For more information, see AWS Fargate capacity providers.
Usage metrics
You can use CloudWatch usage metrics to provide visibility into your accounts usage of resources. Use these metrics to visualize your current service usage on CloudWatch graphs and dashboards.
AWS Fargate usage metrics correspond to AWS service quotas. You can configure alarms that alert you when your usage approaches a service quota. For more information about AWS Fargate service quotas, see AWS Fargate service quotas.
For more information about AWS Fargate usage metrics, see AWS Fargate usage metrics in the Amazon Elastic Container Service User Guide for AWS Fargate.
Task maintenance
When AWS determines that a security or infrastructure update is needed for an Amazon ECS task hosted on AWS Fargate, the tasks need to be stopped and new tasks launched to replace them. For more information, see Task maintenance in the Amazon Elastic Container Service User Guide for AWS Fargate.
The following table describes these scenarios.
Task type | Issue | Action |
---|---|---|
Standalone task |
Host issue |
A task retirement notice is sent using your AWS Health Dashboard |
Security vulnerability |
A task retirement notice is sent using your AWS Health Dashboard |
|
Service task |
Host issue |
The task is stopped by AWS and the service scheduler will launch a new task in an attempt to maintain the service's desired count. No notification is sent. |
Security vulnerability |
A task retirement notice is sent using your AWS Health Dashboard |
Savings plans
Savings Plans are a pricing model that offer significant savings on AWS usage. You commit to a consistent amount of usage, in USD per hour, for a term of 1 or 3 years, and receive a lower price for that usage. For more information, see the Savings Plans User Guide.
To create a Savings Plan for your AWS Fargate usage, use the Compute Savings Plans type. To get started, see Getting started with Savings Plans in the Savings Plans User Guide.
Windows containers on AWS Fargate considerations
Windows containers on AWS Fargate supports the following operating systems:
-
Windows Server 2019 Full
-
Windows Server 2019 Core
-
Windows Server 2022 Full
-
Windows Server 2022 Core
AWS handles the operating system license management, so you do not need any additional Microsoft licenses.
Windows containers on AWS Fargate supports the awslogs driver. For more information, see Using the awslogs log driver.
Your tasks can run either Linux containers or Windows containers. If you need run both container types, you must create separate tasks.
The following features are not supported on Windows containers on Fargate:
-
Group managed service accounts (gMSA)
-
Amazon FSx
-
ENI trunking
-
App Mesh service and proxy integration for tasks
-
Firelens log router integration for tasks
-
Configurable ephemeral storage
-
EFS volumes
-
The following task definition parameters:
-
maxSwap
-
swappiness
-
-
The Fargate Spot capacity provider
-
Image volumes
The Dockerfile
volume
option is ignored. Instead, use bind mounts in your task definition. For more information, see Bind mounts.