Traefik & AWS ECS¶
A Story of Labels & Elastic Containers
Attach labels to your ECS containers and let Traefik do the rest!
Configuration Examples¶
Configuring ECS provider
Enabling the ECS provider:
providers:
ecs: {}
[providers.ecs]
--providers.ecs=true
Policy¶
Traefik needs the following policy to read ECS information:
{
"Version": "2012-10-17",
"Statement": [
{
"Sid": "TraefikECSReadAccess",
"Effect": "Allow",
"Action": [
"ecs:ListClusters",
"ecs:DescribeClusters",
"ecs:ListTasks",
"ecs:DescribeTasks",
"ecs:DescribeContainerInstances",
"ecs:DescribeTaskDefinition",
"ec2:DescribeInstances",
"ssm:DescribeInstanceInformation"
],
"Resource": [
"*"
]
}
]
}
ECS Anywhere
Please note that the ssm:DescribeInstanceInformation
action is required for ECS anywhere instances discovery.
Provider Configuration¶
autoDiscoverClusters
¶
Optional, Default=false
Search for services in cluster list.
- If set to
true
service discovery is enabled for all clusters. - If set to
false
service discovery is enabled on configured clusters only.
providers:
ecs:
autoDiscoverClusters: true
# ...
[providers.ecs]
autoDiscoverClusters = true
# ...
--providers.ecs.autoDiscoverClusters=true
# ...
ecsAnywhere
¶
Optional, Default=false
Enable ECS Anywhere support.
- If set to
true
service discovery is enabled for ECS Anywhere instances. - If set to
false
service discovery is disabled for ECS Anywhere instances.
providers:
ecs:
ecsAnywhere: true
# ...
[providers.ecs]
ecsAnywhere = true
# ...
--providers.ecs.ecsAnywhere=true
# ...
clusters
¶
Optional, Default=["default"]
Search for services in cluster list.
This option is ignored if autoDiscoverClusters
is set to true
.
providers:
ecs:
clusters:
- default
# ...
[providers.ecs]
clusters = ["default"]
# ...
--providers.ecs.clusters=default
# ...
exposedByDefault
¶
Optional, Default=true
Expose ECS services by default in Traefik.
If set to false
, services that do not have a traefik.enable=true
label are ignored from the resulting routing configuration.
providers:
ecs:
exposedByDefault: false
# ...
[providers.ecs]
exposedByDefault = false
# ...
--providers.ecs.exposedByDefault=false
# ...
constraints
¶
Optional, Default=""
The constraints
option can be set to an expression that Traefik matches against the container labels (task),
to determine whether to create any route for that container.
If none of the container labels match the expression, no route for that container is created.
If the expression is empty, all detected containers are included.
The expression syntax is based on the Label("key", "value")
, and LabelRegex("key", "value")
functions,
as well as the usual boolean logic, as shown in examples below.
Constraints Expression Examples
# Includes only containers having a label with key `a.label.name` and value `foo`
constraints = "Label(`a.label.name`, `foo`)"
# Excludes containers having any label with key `a.label.name` and value `foo`
constraints = "!Label(`a.label.name`, `value`)"
# With logical AND.
constraints = "Label(`a.label.name`, `valueA`) && Label(`another.label.name`, `valueB`)"
# With logical OR.
constraints = "Label(`a.label.name`, `valueA`) || Label(`another.label.name`, `valueB`)"
# With logical AND and OR, with precedence set by parentheses.
constraints = "Label(`a.label.name`, `valueA`) && (Label(`another.label.name`, `valueB`) || Label(`yet.another.label.name`, `valueC`))"
# Includes only containers having a label with key `a.label.name` and a value matching the `a.+` regular expression.
constraints = "LabelRegex(`a.label.name`, `a.+`)"
For additional information, refer to Restrict the Scope of Service Discovery.
providers:
ecs:
constraints: "Label(`a.label.name`,`foo`)"
# ...
[providers.ecs]
constraints = "Label(`a.label.name`,`foo`)"
# ...
--providers.ecs.constraints=Label(`a.label.name`,`foo`)
# ...
healthyTasksOnly
¶
Optional, Default=false
Determines whether Traefik discovers only healthy tasks (HEALTHY
healthStatus).
providers:
ecs:
healthyTasksOnly: true
# ...
[providers.ecs]
healthyTasksOnly = true
# ...
--providers.ecs.healthyTasksOnly=true
# ...
defaultRule
¶
Optional, Default=Host(`{{ normalize .Name }}`)
The defaultRule
option defines what routing rule to apply to a container if no rule is defined by a label.
It must be a valid Go template, and can use
sprig template functions.
The container service name can be accessed with the Name
identifier,
and the template has access to all the labels defined on this container.
providers:
ecs:
defaultRule: "Host(`{{ .Name }}.{{ index .Labels \"customLabel\"}}`)"
# ...
[providers.ecs]
defaultRule = "Host(`{{ .Name }}.{{ index .Labels \"customLabel\"}}`)"
# ...
--providers.ecs.defaultRule=Host(`{{ .Name }}.{{ index .Labels \"customLabel\"}}`)
# ...
Default rule and Traefik service
The exposure of the Traefik container, combined with the default rule mechanism, can lead to create a router targeting itself in a loop. In this case, to prevent an infinite loop, Traefik adds an internal middleware to refuse the request if it comes from the same router.
refreshSeconds
¶
Optional, Default=15
Polling interval (in seconds).
providers:
ecs:
refreshSeconds: 15
# ...
[providers.ecs]
refreshSeconds = 15
# ...
--providers.ecs.refreshSeconds=15
# ...
Credentials¶
Optional
If region
is not provided, it is resolved from the EC2 metadata endpoint for EC2 tasks.
In a FARGATE context it is resolved from the AWS_REGION
environment variable.
If accessKeyID
and secretAccessKey
are not provided, credentials are resolved in the following order:
- Using the environment variables
AWS_ACCESS_KEY_ID
,AWS_SECRET_ACCESS_KEY
, andAWS_SESSION_TOKEN
. - Using shared credentials, determined by
AWS_PROFILE
andAWS_SHARED_CREDENTIALS_FILE
, defaults todefault
and~/.aws/credentials
. - Using EC2 instance role or ECS task role
providers:
ecs:
region: us-east-1
accessKeyID: "abc"
secretAccessKey: "123"
# ...
[providers.ecs]
region = "us-east-1"
accessKeyID = "abc"
secretAccessKey = "123"
--providers.ecs.region="us-east-1"
--providers.ecs.accessKeyID="abc"
--providers.ecs.secretAccessKey="123"
# ...