Elastic Container Service
Task
Defines work to be done
Defines everything about the environment where it runs
Placed wherever resources are available
Tasks are immutable, which cannot be changed
Only copy operation can change a task
Life Cycle
Pending -> Running -> Stopped
Scheduled Tasks
Like a super cron
Scheduled through CloudWatch
Scheduled through other services
Started by lambda tasks
Create a task through cli
{ "containerDefinitions": [ { "name": "hello-server", "image": "nginx", "cpu": 384, "memory": 384, "essential": true, "portMappings": [ { "containerPort": 80, "hostPort": 0, "protocol": "tcp" } ] } ], "family": "hello-server" }
$ aws ecs register-task-definition --cli-input-json file://basic-task.json --region us-east-1 { "taskDefinition": { "status": "ACTIVE", "family": "hello-server", "placementConstraints": [], "compatibilities": [ "EC2" ], "volumes": [], "taskDefinitionArn": "arn:aws:ecs:us-east-1:193160586263:task-definition/hello-server:1", "containerDefinitions": [ { "environment": [], "name": "hello-server", "mountPoints": [], "image": "nginx", "cpu": 384, "portMappings": [ { "protocol": "tcp", "containerPort": 80, "hostPort": 0 } ], "memory": 384, "essential": true, "volumesFrom": [] } ], "revision": 1 } } $ aws ecs list-task-definitions --region us-east-1 { "taskDefinitionArns": [ "arn:aws:ecs:us-east-1:193160586263:task-definition/hello-server:1", "arn:aws:ecs:us-east-1:193160586263:task-definition/my-data-server:1", "arn:aws:ecs:us-east-1:193160586263:task-definition/my-data-server:2", "arn:aws:ecs:us-east-1:193160586263:task-definition/my-data-server:3", "arn:aws:ecs:us-east-1:193160586263:task-definition/web-test:1" ] }
Services (管理Tasks)
Supervisors of tasks
Keep a group of tasks running
One task per service
Publish statistics and keep history
Launch Type
Fargate Launch Type
The Fargate launch type allows you to run your containerized applications without the need to provision and manage the backend infrastructure. Just register your task definition and Fargate launches the container for you.
EC2 Launch Type
The EC2 launch type allows you to run your containerized applications on a cluster of Amazon EC2 instances that you manage.
Auto Scaling Groups
A service that starts instances for you
Start identical copies from a template
Tries to maintain the proper number of healthy instances
There are usually controlled by another service called ASG
Local Balancers
ELBs
Data dispatchers for internet-facing relays
Use CloudWatch to monitor the load
Send grow and shrink signals to ASGs
Cluster
Logical group of EC2 instances that you can place containers onto
Task Placement Engine
支持多种容器任务调度策略
Binpacking：最少资源利用（根据 CPU 或者内存）的实例会优先被放置， 这种策略会先将任务放到可用资源最少的实例上，减少了启动过多的实例， 提高了资源利用率。
Spread：根据某个特定值进行平衡放置，这个特定值可以是一个键值对， 也可以是 instanceId 或者 host。一般可使用这种策略实现跨 AZ 的任务放 置。
Affinity：组合条件的放置策略，比如两个符合条件的 task 不能同时放到某 个实例中，或者两个符合条件的 task 必须同时放到某个实例中。
Distinct Instance：将每项任务放置在不同的容器实例中。
ecs-agent
The Amazon ECS Container Agent is a component of Amazon Elastic Container Service (Amazon ECS) and is responsible for managing containers on behalf of Amazon ECS.
https://github.com/aws/amazon-ecs-agent
Manages the state of containers on a single Ec2 instance
How ECS communicates with the docker daemon on the EC2 instance
Must be on every EC2 instance in your ECS Cluster
Included with the ECS-OPTIMIZED AMI
Installation
yum -y install ecs-init service docker start start ecs
watch agent logs
tail -f /var/log/ecs/ecs-agent.log.2019-06-26-02
# docker ps CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES e227b57f9ade amazon/amazon-ecs-agent:latest "/agent" 4 minutes ago Up 4 minutes ecs-agent e05b4c8e247c 193160586263.dkr.ecr.us-east-1.amazonaws.com/nginx "nginx -g 'daemon of…" About an hour ago Up About an hour 0.0.0.0:32768->80/tcp ecs-web-test-1-web-test-8c8ac4ec95d4d6af2400
ecs-refarch-cloudformation
A reference architecture for deploying containerized microservices with Amazon ECS and AWS CloudFormation (YAML)