Docker is a set of platform as a service (PaaS) products that use OS-level virtualization to deliver software in packages called containers. Containers are isolated from one another and bundle their own software, libraries and configuration files; they can communicate with each other through well-defined channels. Note: You can't configure the first step of a pipeline as a manual step. Name- Defines a name for a step to make it easier to see what each step is doing in the display. Image- Bitbucket Pipelines uses Docker containers to run your builds. You can use the default image (atlassian/default-image:2) provided by Bitbucket or define a custom image. Q: When should I use AWS Lambda versus Amazon EC2? Amazon Web Services offers a set of compute services to meet a range of needs. Amazon EC2 offers flexibility, with a wide range of instance types and the option to customize the operating system, network and security settings, and the entire software stack, allowing you to easily move existing applications to the cloud.
Estimated reading time: 21 minutes
Overview
The Docker Compose CLI enables developers to use native Docker commands to run applications in Amazon EC2 Container Service (ECS) when building cloud-native applications.
The integration between Docker and Amazon ECS allows developers to use the Docker Compose CLI to:
- Set up an AWS context in one Docker command, allowing you to switch from a local context to a cloud context and run applications quickly and easily
- Simplify multi-container application development on Amazon ECS using Compose files
Also see the ECS integration architecture, full list of compose features and Compose examples for ECS integration.
Prerequisites
To deploy Docker containers on ECS, you must meet the following requirements:
Download and install Docker Desktop Stable version 2.3.0.5 or later, or Edge version 2.3.2.0 or later.
Alternatively, install the Docker Compose CLI for Linux.
Ensure you have an AWS account.
Docker not only runs multi-container applications locally, but also enablesdevelopers to seamlessly deploy Docker containers on Amazon ECS using aCompose file with the docker compose up
command. The following sectionscontain instructions on how to deploy your Compose application on Amazon ECS.
Run an application on ECS
Requirements
AWS uses a fine-grained permission model, with specific role for each resource type and operation.
To ensure that Docker ECS integration is allowed to manage resources for your Compose application, you have to ensure your AWS credentials grant access to following AWS IAM permissions:
- application-autoscaling:*
- cloudformation:*
- ec2:AuthorizeSecurityGroupIngress
- ec2:CreateSecurityGroup
- ec2:CreateTags
- ec2:DeleteSecurityGroup
- ec2:DescribeRouteTables
- ec2:DescribeSecurityGroups
- ec2:DescribeSubnets
- ec2:DescribeVpcs
- ec2:RevokeSecurityGroupIngress
- ecs:CreateCluster
- ecs:CreateService
- ecs:DeleteCluster
- ecs:DeleteService
- ecs:DeregisterTaskDefinition
- ecs:DescribeClusters
- ecs:DescribeServices
- ecs:DescribeTasks
- ecs:ListAccountSettings
- ecs:ListTasks
- ecs:RegisterTaskDefinition
- ecs:UpdateService
- elasticloadbalancing:*
- iam:AttachRolePolicy
- iam:CreateRole
- iam:DeleteRole
- iam:DetachRolePolicy
- iam:PassRole
- logs:CreateLogGroup
- logs:DeleteLogGroup
- logs:DescribeLogGroups
- logs:FilterLogEvents
- route53:CreateHostedZone
- route53:DeleteHostedZone
- route53:GetHealthCheck
- route53:GetHostedZone
- route53:ListHostedZonesByName
- servicediscovery:*
GPU support, which relies on EC2 instances to run containers with attached GPU devices,require a few additional permissions:
- ec2:DescribeVpcs
- autoscaling:*
- iam:CreateInstanceProfile
- iam:AddRoleToInstanceProfile
- iam:RemoveRoleFromInstanceProfile
- iam:DeleteInstanceProfile
Create AWS context
Run the docker context create ecs myecscontext
command to create an Amazon ECS Dockercontext named myecscontext
. If you have already installed and configured the AWS CLI,the setup command lets you select an existing AWS profile to connect to Amazon.Otherwise, you can create a new profile by passing anAWS access key ID and a secret access key.Finally, you can configure your ECS context to retrieve AWS credentials by AWS_*
environment variables, which is a common way to integrate withthird-party tools and single-sign-on providers.
After you have created an AWS context, you can list your Docker contexts by running the docker context ls
command:
Run a Compose application
You can deploy and manage multi-container applications defined in Compose filesto Amazon ECS using the docker compose
command. To do this:
Ensure you are using your ECS context. You can do this either by specifyingthe
--context myecscontext
flag with your command, or by setting thecurrent context using the commanddocker context use myecscontext
.Run
docker compose up
anddocker compose down
to start and thenstop a full Compose application.By default,
docker compose up
uses thecompose.yaml
ordocker-compose.yaml
Mac app store excel software. file inthe current folder. You can specify the working directory using the --workdir flag orspecify the Compose file directly usingdocker compose --file mycomposefile.yaml up
.You can also specify a name for the Compose application using the
--project-name
flag during deployment. If no name is specified, a name will be derived from the working directory.
Docker ECS integration converts the Compose application model into a set of AWS resources, described as a CloudFormation template. The actual mapping is described in technical documentation.You can review the generated template using docker compose convert
command, and follow CloudFormation applying this model withinAWS web console when you run docker compose up
, in addition to CloudFormation events being displayedin your terminal.
You can view services created for the Compose application on Amazon ECS andtheir state using the
docker compose ps
command.You can view logs from containers that are part of the Compose applicationusing the
docker compose logs
command.
Also see the full list of compose features.
Rolling update
To update your application without interrupting production flow you can simplyuse docker compose up
on the updated Compose project.Your ECS services are created with rolling update configuration. As you rundocker compose up
with a modified Compose file, the stack will beupdated to reflect changes, and if required, some services will be replaced.This replacement process will follow the rolling-update configuration set byyour services deploy.update_config
configuration.
AWS ECS uses a percent-based model to define the number of containers to berun or shut down during a rolling update. The Docker Compose CLI computesrolling update configuration according to the parallelism
and replicas
fields. However, you might prefer to directly configure a rolling updateusing the extension fields x-aws-min_percent
and x-aws-max_percent
.The former sets the minimum percent of containers to run for service, and thelatter sets the maximum percent of additional containers to start beforeprevious versions are removed.
By default, the ECS rolling update is set to run twice the number ofcontainers for a service (200%), and has the ability to shut down 100%containers during the update.
View application logs
The Docker Compose CLI configures AWS CloudWatch Logs service for yourcontainers.By default you can see logs of your compose application the same way you check logs of local deployments:
A log group is created for the application as docker-compose/<application_name>
,and log streams are created for each service and container in your applicationas <application_name>/<service_name>/<container_ID>
.
You can fine tune AWS CloudWatch Logs using extension field x-aws-logs_retention
in your Compose file to set the number of retention days for log events. Thedefault behavior is to keep logs forever.
You can also pass awslogs
parameters to your container as standardCompose file logging.driver_opts
elements. See AWS documentation for details on available log driver options.
Private Docker images
The Docker Compose CLI automatically configures authorization so you can pull private images from the Amazon ECR registry on the same AWS account. To pull private images from another registry, including Docker Hub, you’ll have to create a Username + Password (or a Username + Token) secret on the AWS Secrets Manager service.
For your convenience, the Docker Compose CLI offers the docker secret
command, so you can manage secrets created on AWS SMS without having to install the AWS CLI.
First, create a token.json
file to define your DockerHub username and access token.
For instructions on how to generate access tokens, see Managing access tokens.
You can then create a secret from this file using docker secret
:
Once created, you can use this ARN in you Compose file using using x-aws-pull_credentials
custom extension with the Docker image URI for your service.
Note
If you set the Compose file version to 3.8 or later, you can use the same Compose file for local deployment using docker-compose
. Custom ECS extensions will be ignored in this case.
Service discovery
Service-to-service communication is implemented transparently by default, so you can deploy your Compose applications with multiple interconnected services without changing the compose file between local and ECS deployment. Individual services can run with distinct constraints (memory, cpu) and replication rules.
Service names
Services are registered automatically by the Docker Compose CLI on AWS Cloud Map during application deployment. They are declared as fully qualified domain names of the form: <service>.<compose_project_name>.local
.
Services can retrieve their dependencies using Compose service names (as they do when deploying locally with docker-compose), or optionally use the fully qualified names.
Dependent service startup time and DNS resolution
Services get concurrently scheduled on ECS when a Compose file is deployed. AWS Cloud Map introduces an initial delay for DNS service to be able to resolve your services domain names. Your code needs to support this delay by waiting for dependent services to be ready, or by adding a wait-script as the entrypoint to your Docker image, as documented in Control startup order.Note this need to wait for dependent services in your Compose application also exists when deploying locally with docker-compose, but the delay is typically shorter. Issues might become more visible when deploying to ECS if services do not wait for their dependencies to be available.
Alternatively, you can use the depends_on feature of the Compose file format. By doing this, dependent service will be created first, and application deployment will wait for it to be up and running before starting the creation of the dependent services.
Service isolation
Service isolation is implemented by the Security Groups rules, allowing services sharing a common Compose file “network” to communicate together using their Compose service names.
Volumes
ECS integration supports volume management based on Amazon Elastic File System (Amazon EFS).For a Compose file to declare a volume
, ECS integration will define creation of an EFSfile system within the CloudFormation template, with Retain
policy so data won’tbe deleted on application shut-down. If the same application (same project name) isdeployed again, the file system will be re-attached to offer the same user experiencedevelopers are used to with docker-compose.
A basic compose service using a volume can be declared like this:
With no specific volume options, the volume still must be declared in the volumes
section forthe compose file to be valid (in the above example the empty mydata:
entry)If required, the initial file system can be customized using driver-opts
:
File systems created by executing docker compose up
on AWS can be listed usingdocker volume ls
and removed with docker volume rm <filesystemID>
.
An existing file system can also be used for users who already have data stored on EFSor want to use a file system created by another Compose stack.
Docker Aws Configure
Accessing a volume from a container can introduce POSIX user IDpermission issues, as Docker images can define arbitrary user ID / group ID for theprocess to run inside a container. However, the same uid:gid
will have to matchPOSIX permissions on the file system. To work around the possible conflict, you can set the volumeuid
and gid
to be used when accessing a volume:
Secrets
You can pass secrets to your ECS services using Docker model to bind sensitivedata as files under /run/secrets
. If your Compose file declares a secret asfile, such a secret will be created as part of your application deployment onECS. If you use an existing secret as external: true
reference in yourCompose file, use the ECS Secrets Manager full ARN as the secret name:
Secrets will be available at runtime for your service as a plain text file /run/secrets/foo
.
The AWS Secrets Manager allows you to store sensitive data either as a plaintext (like Docker secret does), or as a hierarchical JSON document. You canuse the latter with Docker Compose CLI by using custom field x-aws-keys
todefine which entries in the JSON document to bind as a secret in your servicecontainer.
By doing this, the secret for bar
key will be available at runtime for yourservice as a plain text file /run/secrets/foo/bar
. You can use the specialvalue *
to get all keys bound in your container.
Auto scaling
Scaling service static information (non auto-scaling) can be specified using the normal Compose syntax:
The Compose file model does not define any attributes to declare auto-scaling conditions.Therefore, we rely on x-aws-autoscaling
custom extension to define the auto-scaling range, aswell as cpu or memory to define target metric, expressed as resource usage percent.
IAM roles
Your ECS Tasks are executed with a dedicated IAM role, granting accessto AWS Managed policiesAmazonECSTaskExecutionRolePolicy
and AmazonEC2ContainerRegistryReadOnly
.In addition, if your service uses secrets, IAM Role gets additionalpermissions to read and decrypt secrets from the AWS Secret Manager.
You can grant additional managed policies to your service executionby using x-aws-policies
inside a service definition:
You can also write your own IAM Policy Documentto fine tune the IAM role to be applied to your ECS service, and usex-aws-role
inside a service definition to pass theyaml-formatted policy document.
Tuning the CloudFormation template
The Docker Compose CLI relies on Amazon CloudFormation to manage the application deployment. To get more control on the created resources, you can use docker compose convert
to generate a CloudFormation stack file from your Compose file. This allows you to inspect resources it defines, or customize the template for your needs, and then apply the template to AWS using the AWS CLI, or the AWS web console.
Once you have identified the changes required to your CloudFormation template, you can include overlays in yourCompose file that will be automatically applied on compose up
. An overlay is a yaml object that uses the same CloudFormation template data structure as the one generated by ECS integration, but only contains attributes tobe updated or added. It will be merged with the generated template before being applied on the AWS infrastructure.
Adjusting Load Balancer http HealthCheck configuration
While ECS cluster uses the HealthCheck
command on container to get service health, Application Load Balancers definetheir own URL-based HealthCheck mechanism so traffic gets routed. As the Compose model does not offer such anabstraction (yet), the default one is applied, which queries your service under /
expecting HTTP status code200
.
You can tweak this behavior using a cloudformation overlay by following the AWS CloudFormation User Guide forconfiguration reference:
Setting SSL termination by Load Balancer
You can use Application Load Balancer to handle the SSL termination for HTTPS services, so that your code, which ran insidea container, doesn’t have to. This is currently not supported by the ECS integration due to the lack of an equivalent abstraction in the Compose specification. However, you can rely on overlays to enable this feature on generated Listeners configuration:
Using existing AWS network resources
By default, the Docker Compose CLI creates an ECS cluster for your Compose application, a Security Group per network in your Compose file on your AWS account’s default VPC, and a LoadBalancer to route traffic to your services.
With the following basic compose file, the Docker Compose CLI will automatically create these ECS constructs including the load balancer to route traffic to the exposed port 80.
If your AWS account does not have permissions to create such resources, or if you want to manage these yourself, you can use the following custom Compose extensions:
Use
x-aws-cluster
as a top-level element in your Compose file to set the IDof an ECS cluster when deploying a Compose application. Otherwise, acluster will be created for the Compose project.Use
x-aws-vpc
as a top-level element in your Compose file to set the ARNof a VPC when deploying a Compose application.Use
x-aws-loadbalancer
as a top-level element in your Compose file to setthe ARN of an existing LoadBalancer.
The latter can be used for those who want to customize application exposure, typically touse an existing domain name for your application:
- Use the AWS web console or CLI to get your VPC and Subnets IDs. You can retrieve the default VPC ID and attached subnets using this AWS CLI commands:
- Use the AWS CLI to create your load balancer. The AWS Web Console can also be used but will require adding at least one listener, which we don’t need here.
To assign your application an existing domain name, you can configure your DNS with aCNAME entry pointing to just-created loadbalancer’s
DNSName
reported as you created the loadbalancer.Use Loadbalancer ARN to set
x-aws-loadbalancer
in your compose file, and deploy your application usingdocker compose up
command.
Please note Docker ECS integration won’t be aware of this domain name, so docker compose ps
command will report URLs with loadbalancer DNSName, not your own domain.
You also can use external: true
inside a network definition in your Compose file forDocker Compose CLI to not create a Security Group, and set name
with theID of an existing SecurityGroup you want to use for network connectivity betweenservices:
Local simulation
When you deploy your application on ECS, you may also rely on the additional AWS services.In such cases, your code must embed the AWS SDK and retrieve API credentials at runtime.AWS offers a credentials discovery mechanism which is fully implemented by the SDK, and relieson accessing a metadata service on a fixed IP address.
Once you adopt this approach, running your application locally for testing or debug purposescan be difficult. Therefore, we have introduced an option on context creation to set theecs-local
context to maintain application portability between local workstation and theAWS cloud provider.
When you select a local simulation context, running the docker compose up
command doesn’tdeploy your application on ECS. Therefore, you must run it locally, automatically adjusting your Composeapplication so it includes the ECS local endpoints.This allows the AWS SDK used by application code toaccess a local mock container as “AWS metadata API” and retrieve credentials from your ownlocal .aws/credentials
config file.
Install the Docker Compose CLI on Linux
The Docker Compose CLI adds support for running and managing containers on ECS.
Install Prerequisites
Install script
You can install the new CLI using the install script:
FAQ
What does the error this tool requires the 'new ARN resource ID format'
mean?
This error message means that your account requires the new ARN resource ID format for ECS. To learn more, see Migrating your Amazon ECS deployment to the new ARN and resource ID format.
Feedback
Thank you for trying out the Docker Compose CLI. Your feedback is very important to us. Let us know your feedback by creating an issue in the Compose CLI GitHub repository.