https://github.com/chrispsheehan/fargate-auto-scaled-backend
ECS Auto-Scaling backend using a blue/green deployment strategy, within a private VPC
https://github.com/chrispsheehan/fargate-auto-scaled-backend
auto-scaling aws aws-ecs-fargate bluegreen-deployment codedeploy terraform vpc-network
Last synced: 2 months ago
JSON representation
ECS Auto-Scaling backend using a blue/green deployment strategy, within a private VPC
- Host: GitHub
- URL: https://github.com/chrispsheehan/fargate-auto-scaled-backend
- Owner: chrispsheehan
- Created: 2024-09-10T15:20:12.000Z (9 months ago)
- Default Branch: main
- Last Pushed: 2024-10-28T17:03:04.000Z (7 months ago)
- Last Synced: 2024-10-28T18:41:45.826Z (7 months ago)
- Topics: auto-scaling, aws, aws-ecs-fargate, bluegreen-deployment, codedeploy, terraform, vpc-network
- Language: HCL
- Homepage:
- Size: 300 KB
- Stars: 2
- Watchers: 1
- Forks: 0
- Open Issues: 1
-
Metadata Files:
- Readme: README.md
Awesome Lists containing this project
README
# fargate-auto-scaled-backend
A load balanced and auto-scaled api running on AWS ECS.
## vpc
A VPC with the below resources is required. Console VPC wizard can create them.
## ci
`Init` workflow - manual trigger
1. **ecs-check** Query AWS for existing of service `[obtain current task arn]`.
2. **ecr** Apply ECR and vpc endpoints.
3. **build/image** `[if service doesn't exist]` Push a new *initial* image to ecr.
4. **build/task** `[if service doesn't exist]` Create a new task definition is created.
5. **setup/service** Apply ecs service, deploy and auto-scaling.
6. **setup/network** Apply vpc link, load balancer and api gateway ingress.
7. **test** Basic check on the API `/host` endpoint.
`Deploy` workflow - push on `main` trigger
1. **code/image** Build image if changes to `src/*` detected.
2. **code/task** Apply task definition (no changes if the same image).
3. **check** Create a `deploy` boolean based on a new task definition (difference to current) detected.
4. **deploy** `[if deploy=true]` Codedeploy deployment is created and status is monitored.
5. A *blue/green* deployment takes place.
`Destroy` workflow - manual trigger
1. **service** Destroy ecs service, deploy and auto-scaling resources.
2. **network** Destroy vpc link, load balancer and api gateway ingress resources.
3. **task** Destroy task definition.
4. **ecr** Destroy ecr and images.
## usage
- obtain `url` from terraform - found in github action `init / setup / network outputs`
- `curl [url]/dev/host`
```sh
{
"message":"Request handled by backend at 2024-09-25T12:28:17.593Z",
"imageUri":"700011111111.dkr.ecr.eu-west-2.amazonaws.com/fargate-auto-scaled-backend@sha256:78dfc01946306dd6afea2b47b56e196788501bfa93c1b2ee1e90a54e72b56938",
"hostname":"ip-10-55-161-195.eu-west-2.compute.internal"
}
```
## cpu autoscaling
ECS will auto-scale when CPU reaching upper and lower limits. CPU is for entire ECS service.
Initially, the `scale-down-alarm` cloudwatch alarm state will be `In Alarm` as CPU will be < scale down threshold. **This is expected**.
Simulate a load on the ECS service with `curl [URL]/dev/stress-cpu/75/120`. This example will run 75% CPU load for 120 seconds.
After that load has completed and the =< 1 minute cool off period. This will trigger a cloudwatch alarm which will in turn trigger the auto-scaling rule(s).
Once that load has finished - after the 120 seconds - the scale down alarm will be triggered and the tasks scaled back down.
### setup
In `tf/service` the below variables are to be considered.
- `cpu_scale_up_threshold`: percentage CPU load to trigger a scale up of tasks.
- `cpu_scale_down_threshold`: percentage CPU load to trigger a scale down of tasks.
- `max_scaled_task_count`: maximum amount of tasks to be allowed.
## docker
```sh
docker build -t express-app .
docker run -i -e BASE_PATH=dev -p 3000:3000 express-app
```
## terraform
Required deployment iam privileges.
```json
[
"dynamodb:*",
"s3:*",
"ecr:*",
"iam:*",
"ecs:*",
"ec2:*",
"elasticloadbalancing:*",
"application-autoscaling:*",
"logs:*",
"cloudwatch:*",
"apigateway:*",
"codedeploy:*"
]
```
## ci config
Required github action variables.
- `AWS_ACCOUNT_ID`
- `AWS_REGION`
- `AWS_ROLE` role with above deployment privileges