Amazon ECS

Manage cluster, task-definition and service records.

Plan: Pro76 of 77 operations implemented, 1 failed in testing4Known differences

A service can report running tasks while its deployment and task set count none, and RunTask returns HTTP 501 NotIncluded in Vera 1.2.0-rc.3.

Example checked on Vera 1.2.2, 8 November 2026. Each coverage note names its own evidence and date.

Connect

Activate your license key and start the emulator with the Vera launcher, as in Activate Pro, then run this in a terminal of its own, from an empty scratch directory. It gives the official AWS CLI dummy credentials and a config file of its own, so no AWS account is needed and your own AWS profile isn't touched.

export VERA_ENDPOINT="http://localhost:5003"
export AWS_ACCESS_KEY_ID=test AWS_SECRET_ACCESS_KEY=test
export AWS_REGION=us-east-1 AWS_DEFAULT_REGION=us-east-1
export AWS_SHARED_CREDENTIALS_FILE=/dev/null
export AWS_EC2_METADATA_DISABLED=true
export AWS_PAGER="" AWS_CLI_AUTO_PROMPT=off
unset AWS_PROFILE AWS_DEFAULT_PROFILE
unset AWS_SESSION_TOKEN AWS_SECURITY_TOKEN
unset AWS_WEB_IDENTITY_TOKEN_FILE AWS_ROLE_ARN AWS_ROLE_SESSION_NAME
unset AWS_CONTAINER_CREDENTIALS_FULL_URI
unset AWS_CONTAINER_CREDENTIALS_RELATIVE_URI
cat > vera-aws-config <<'EOF'
[default]
region = us-east-1
output = json
cli_binary_format = base64
s3 =
    addressing_style = path
EOF
export AWS_CONFIG_FILE="$PWD/vera-aws-config"

When you've finished every example in this terminal, close it and delete vera-aws-config, not before.

Use the AWS CLI’s ecs commands. The emulator serves the 2014-11-13 API over the AWS JSON protocol, and the examples use us-east-1.

Cluster and service ARNs carry the region local instead of the one you signed for, such as arn:aws:ecs:local:123456789012:cluster/vera-docs-cluster, while task definition ARNs carry us-east-1. Pass ARNs exactly as the emulator returns them.

Example

Create a cluster, register a Fargate task definition and create a service from it with no tasks, then raise its desired count to 1 and describe the service. The image is an example name that’s never pulled.

CLUSTER_ARN=$(aws --endpoint-url "$VERA_ENDPOINT" ecs create-cluster \
  --cluster-name vera-docs-cluster --query cluster.clusterArn --output text)
TASK_DEF_ARN=$(aws --endpoint-url "$VERA_ENDPOINT" ecs register-task-definition \
  --family vera-docs-task --network-mode awsvpc --requires-compatibilities FARGATE \
  --cpu 256 --memory 512 \
  --container-definitions '[{"name": "web", "image": "example.net/docs-image:latest", "essential": true}]' \
  --query taskDefinition.taskDefinitionArn --output text)
aws --endpoint-url "$VERA_ENDPOINT" ecs create-service \
  --cluster "$CLUSTER_ARN" --service-name vera-docs-service \
  --task-definition "$TASK_DEF_ARN" --desired-count 0 --launch-type FARGATE
aws --endpoint-url "$VERA_ENDPOINT" ecs update-service \
  --cluster "$CLUSTER_ARN" --service vera-docs-service --desired-count 1
aws --endpoint-url "$VERA_ENDPOINT" ecs describe-services \
  --cluster "$CLUSTER_ARN" --services vera-docs-service

The emulator accepts this Fargate service without network configuration, so don’t use the example as a recipe for AWS. These are selected fields from the last command’s output:

{
  "services": [
    {
      "serviceName": "vera-docs-service",
      "status": "ACTIVE",
      "desiredCount": 1,
      "runningCount": 1,
      "taskSets": [
        {
          "pendingCount": 0,
          "runningCount": 0
        }
      ],
      "deployments": [
        {
          "desiredCount": 0,
          "pendingCount": 0,
          "runningCount": 0
        }
      ]
    }
  ]
}

The service’s desired and running counts became 1 at once, while its task set and deployment still count none. These are counters on a record: no container started. The update also replaced several of the service’s deployment settings with zero or empty defaults.

To clean up, scale the service back to 0, delete it, deregister the task definition and delete the cluster. Deregistering makes the task definition inactive rather than erasing it:

aws --endpoint-url "$VERA_ENDPOINT" ecs update-service \
  --cluster "$CLUSTER_ARN" --service vera-docs-service --desired-count 0
aws --endpoint-url "$VERA_ENDPOINT" ecs delete-service \
  --cluster "$CLUSTER_ARN" --service vera-docs-service --force
aws --endpoint-url "$VERA_ENDPOINT" ecs deregister-task-definition --task-definition "$TASK_DEF_ARN"
aws --endpoint-url "$VERA_ENDPOINT" ecs delete-cluster --cluster "$CLUSTER_ARN"

Supported features

Clusters, task definitions and services as records: create, describe, change a service’s desired count, and delete or deregister. Their metadata works as the example shows.
Regions kept apart: a cluster created in us-east-1 isn’t returned when described in us-west-2.
Listed in the earlier implementation inventory; not rechecked against Vera 1.2.0-rc.3: capacity providers, task sets and service deployments, container instances, daemons, account settings, attributes, ECS Exec and tags.

Limitations

The main limits are below. A few more apply to every service, and the API coverage notes cover smaller differences.

Tasks can’t be run in Vera 1.2.0-rc.3. RunTask returns HTTP 501 NotIncluded, because this release doesn’t include the task engine, and a Pro license doesn’t add it. In Vera 1.2.0 preview, RunTask created task records that DescribeTasks, ListTasks and StopTask worked on, but no container started.
No containers ran. No container engine, image pull, traffic, ECS Exec or logs were verified. Services are records: the example’s service reports a running task though nothing started.
Counts don’t reconcile. Changing a service’s desired count reports the same number running at once, while its task set and deployment keep counting none. Don’t read scheduling or container readiness from these counters.
Region local in ARNs. Clusters and services signed for us-east-1 get ARNs in the region local.
Services can’t be scaling targets. In testing of Vera 1.2.0 preview, Application Auto Scaling rejected an existing ECS service as not found.

API coverage

Every operation in AWS's published 2014-11-13 API (SDK model, botocore 1.43.105), and whether the emulator implements it. Availability combines the earlier implementation inventory with the dated observations below; checking a page's example does not verify every operation. Each note names its evidence first; an observation given without a build or date comes from earlier testing, on 3 November 2026. What the statuses mean

Operation	Status	Notes
ContinueServiceDeployment	Implemented
CreateCapacityProvider	Implemented
CreateCluster	Known difference	Local observation: Returns a cluster ARN in the region `local` instead of the one you signed for. Local observation: Vera 1.2.0 preview, 5 November 2026 — the same.
CreateDaemon	Implemented
CreateExpressGatewayService	Implemented
CreateService	Known difference	Local observation: Returns service ARNs in the region `local`. The service is a record: no tasks started in testing. Local observation: Vera 1.2.0 preview, 5 November 2026 — the same, and a Fargate service was accepted without network configuration.
CreateTaskSet	Implemented
DeleteAccountSetting	Implemented
DeleteAttributes	Implemented
DeleteCapacityProvider	Implemented
DeleteCluster	Implemented	Local observation: Vera 1.2.0 preview, 5 November 2026 — deleted the example's cluster.
DeleteDaemon	Implemented
DeleteDaemonTaskDefinition	Implemented
DeleteExpressGatewayService	Implemented
DeleteService	Implemented	Local observation: Vera 1.2.0 preview, 5 November 2026 — deleted the example's service with `--force` after it was scaled back to 0.
DeleteTaskDefinitions	Implemented
DeleteTaskSet	Implemented
DeregisterContainerInstance	Implemented
DeregisterTaskDefinition	Implemented	Local observation: Vera 1.2.0 preview, 5 November 2026 — deregistered the example's task definition, which becomes inactive rather than erased.
DescribeCapacityProviders	Implemented
DescribeClusters	Implemented	Local observation: Vera 1.2.0 preview, 5 November 2026 — a cluster created in `us-east-1` wasn't returned by a request to `us-west-2`.
DescribeContainerInstances	Implemented
DescribeDaemon	Implemented
DescribeDaemonDeployments	Implemented
DescribeDaemonRevisions	Implemented
DescribeDaemonTaskDefinition	Implemented
DescribeExpressGatewayService	Implemented
DescribeServiceDeployments	Implemented
DescribeServiceRevisions	Implemented
DescribeServices	Known difference	Local observation: Vera 1.2.0 preview, 5 November 2026 — after the desired count was raised to 1, reported the service's `desiredCount` and `runningCount` as 1, but 0 running and pending for its task set and 0 desired, running and pending for its deployment. The counters don't show a running container.
DescribeTaskDefinition	Implemented
DescribeTaskSets	Implemented
DescribeTasks	Implemented	Local observation: Vera 1.2.0 preview, 5 November 2026 — described a task record from `RunTask`.
DiscoverPollEndpoint	Implemented
ExecuteCommand	Implemented
GetTaskProtection	Implemented
ListAccountSettings	Implemented
ListAttributes	Implemented
ListClusters	Implemented
ListContainerInstances	Implemented
ListDaemonDeployments	Implemented
ListDaemonTaskDefinitions	Implemented
ListDaemons	Implemented
ListServiceDeployments	Implemented
ListServices	Implemented
ListServicesByNamespace	Implemented
ListTagsForResource	Implemented
ListTaskDefinitionFamilies	Implemented
ListTaskDefinitions	Implemented
ListTasks	Implemented	Local observation: Vera 1.2.0 preview, 5 November 2026 — listed a task record from `RunTask`.
PutAccountSetting	Implemented
PutAccountSettingDefault	Implemented
PutAttributes	Implemented
PutClusterCapacityProviders	Implemented
RegisterContainerInstance	Implemented
RegisterDaemonTaskDefinition	Implemented
RegisterTaskDefinition	Implemented	Local observation: Vera 1.2.0 preview, 5 November 2026 — registered a Fargate task definition, whose ARN carries `us-east-1`. Its image wasn't pulled.
RunTask	Failed in testing	Local observation: Vera 1.2.0-rc.3, 6 November 2026 — returns HTTP 501 `NotIncluded`, because this Vera release doesn't include the task engine. A Pro license doesn't add the engine. The request named a cluster and task definition that don't exist; the refusal came before either was looked up. The earlier observations that follow don't describe Vera 1.2.0-rc.3. Local observation: earlier testing, 3 November 2026 — returned ARNs in the region `local`. Tasks were records: no image was pulled and no container started. Local observation: Vera 1.2.0 preview, 5 November 2026 — created a task record; no container started.
StartTask	Implemented
StopServiceDeployment	Implemented
StopTask	Implemented	Local observation: Vera 1.2.0 preview, 5 November 2026 — stopped a task record from `RunTask`.
SubmitAttachmentStateChanges	Implemented
SubmitContainerStateChange	Implemented
SubmitTaskStateChange	Implemented
TagResource	Implemented
UntagResource	Implemented
UpdateCapacityProvider	Implemented
UpdateCluster	Implemented
UpdateClusterSettings	Implemented
UpdateContainerAgent	Implemented
UpdateContainerInstancesState	Implemented
UpdateDaemon	Implemented
UpdateExpressGatewayService	Implemented
UpdateService	Known difference	A new desired count is reported as running at once, while the service's task set and deployment still count none. Local observation: Vera 1.2.0 preview, 5 November 2026 — the same, and the update also replaced several deployment settings with zero or empty defaults. No container started.
UpdateServicePrimaryTaskSet	Implemented
UpdateTaskProtection	Implemented
UpdateTaskSet	Implemented