- ECS is managed container orchestrator
- like docker swarm , kubernetes
- manage life cycle of container create / restart / destroy
- Deploy & load-balance application across multiple servers
- Autoscaling to handle variance in traffic
- Rolling out changes to application
- As compared to ECS, The Kubernetes , Doker Swarm and HashiCrop Nomad etc they all are more effort to get up and running and they are not exactly the simplest or more intuitive to work with especially with kubernetes it is a beast
- ECS is a simple alternative to these orchestration so that we can basically just use a simple GUI put couples of details that we want our application to operate and AWS is going to handle the rest
ECS has two different launch type
- EC2 which is a compute service
- FARGATE which is Serverless way
Cluster
- Underlying resources that are ECS intances that can deploy your application it is a physical infractructure
EC2 Launch
- We have to manage the underlying EC2 instances
- We have ECS control plane which is brain behind the operation on container
- We have launch Cluster
- We have manage dependency on EC2 we have to install Docker to run containers
- We have to install the ECS agents so we can connect the control plane to instance
- Installing firewall to access certain ports
- Apply routine patches so that our servers all up to date
- The only think ECS does is manage the containers it deploys the containers onto those ec2 instances
ECS Fargate Launch
- It follows a serverless architecture
- There will we no EC2 intances ,no physical servers
- We only have to create application and send it to ECS
- ECS is going to do that it will see cluster their are servers or not
- Then tell to Fargate and Fargate will create servers on demand Fargate is going to handle
- Once Fargate create demand then ECS can then deploy our container onto newly created infrastructure
- We do not need to provision or maintain the ec2 servers fargate does all of that for you under the hood
- We only pay for what we use
ECS Task Defination
- It is a Blueprint that describes how container should be launch
- It contains how much CPU/Memory should be use
- It contains which image / ports / volume should be use
- Basically it is going to contain all of the configuration that a docker-compose file should contains
- Task
- An instance of a Task Definition is knows as Task
- If we want two intances we would have two separate Tasks
ECS Services
- A service ensures that a certain number of Task are running at all times
- Restarts containers that have exited/crashed
- EC2 instance fails, the Service will restart task on a working EC2
- We can also assign a load balancer to the service and load balancer can be assigned to route external traffic to your service