https://github.com/chrispsheehan/weighted-target-traffic
Incrementally move traffic from Lambda to ECS using weighted routing in AWS. Manage deployments and resources with Terraform
https://github.com/chrispsheehan/weighted-target-traffic
aws ecs lambda terraform weighted-routing
Last synced: over 1 year ago
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Incrementally move traffic from Lambda to ECS using weighted routing in AWS. Manage deployments and resources with Terraform
- Host: GitHub
- URL: https://github.com/chrispsheehan/weighted-target-traffic
- Owner: chrispsheehan
- Created: 2024-10-11T15:33:30.000Z (over 1 year ago)
- Default Branch: main
- Last Pushed: 2024-10-29T11:36:20.000Z (over 1 year ago)
- Last Synced: 2024-10-29T13:25:47.565Z (over 1 year ago)
- Topics: aws, ecs, lambda, terraform, weighted-routing
- Language: HCL
- Homepage:
- Size: 198 KB
- Stars: 3
- Watchers: 1
- Forks: 0
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
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README
# weighted-target-traffic
Send weighted (percentage of) traffic to different aws resources.
In this use case we can incrementally move endpoints to ECS from Lambda.
`Deploy` workflow - push on `main` trigger
1. **validate** Check terraform code for any errors.
2. **repo** Setup ECR and S3 repositories.
3. **network** Apply vpc link and api gateway ingress along with load balancer and rules.
4. **image** Build image if changes to `src/*` detected
5. **code** Build Lambda code as zip if changes to `src/*` detected
6. **ecs** Apply ECS cluster, service and task. Rolling deployment only.
7. **lambda** Apply Lambda.
`Destroy` workflow - manual trigger
1. **ecs** Destroy ecs service and task.
2. **lambda** Destroy lambda.
3. **network** Destroy vpc link and api gateway ingress resources.
4. **repo** Destroy ecr, images and lambda s3 zips.
## path weighting rules
- Passed in as `terraform apply -var='weighted_rules={}'` default value json shown below.
- For each path define weighting to lambda and/or ecs.
- In the below:
- `host` will be weighted 50/50 to ecs/lambda.
- `small-woodland-creature` will go to ecs only.
- `ice-cream-flavour` will go to lambda only.
```hcl
{
"host" = {
ecs_percentage_traffic = 50
lambda_percentage_traffic = 50
priority = 300
},
"small-woodland-creature" = {
ecs_percentage_traffic = 100
lambda_percentage_traffic = 0
priority = 200
},
"ice-cream-flavour" = {
ecs_percentage_traffic = 0
lambda_percentage_traffic = 100
priority = 100
}
}
```
- Default values are set with `terraform apply -var='default_weighting'` the below example sends all traffic to lambda.
```hcl
{
ecs_percentage_traffic = 0
lambda_percentage_traffic = 100
}
```
## terraform
Required deployment iam privileges.
```json
[
"dynamodb:*",
"s3:*",
"ecr:*",
"iam:*",
"ecs:*",
"ec2:*",
"elasticloadbalancing:*",
"logs:*",
"cloudwatch:*",
"apigateway:*",
"lambda:*"
]
```
## ci config
Required github action variables.
- `AWS_ACCOUNT_ID`
- `AWS_REGION`
- `AWS_ROLE` role with above deployment privileges
## additional spice
Unable to destroy lambda security group (sg). Terraform attempts to delete the sg and is blocked which causes a timeout failure.
**Cause**: lambda is deployed within a VPC by specifying `vpc_config` in the `aws_lambda_function` terraform block.
**Reason**: elastic network interfaces (enis) associated with the sg are still in use on the lambda. This blocks a deletion.
**Solution**: remove the `vpc_config` from the lambda via cli prior to a destroy. This is done via `just detach-function`.