Scaffold Infra Repo & CDK Project

Objective

Create an AWS CDK Python project with Makefile for infra operations and a GitHub Actions workflow placeholder. Layout depends on deployment style from DCI-01.

Process

Path Selection

Refer to docs/architecture/INFRA_REQUIREMENTS.md § Deployment Style.

Monorepo note (EB): Small teams often keep infra/ in the app repo. CDK deploy and app CI/CD share secrets via infra/.env. Separate repo still valid for larger orgs.

EKS Path

1. Create Infra Repository

mkdir {project}-infra && cd {project}-infra && git init

2. Initialize CDK Project

python3 -m venv .venv && source .venv/bin/activate
pip install aws-cdk-lib constructs
mkdir -p stacks tests

Create app.py wiring VpcStack, EksStack, DnsStack.

3. Directory Structure

{project}-infra/
├── app.py
├── cdk.json
├── requirements.txt
├── Makefile
├── .github/workflows/infra.yml
├── stacks/
│   ├── vpc_stack.py
│   ├── eks_stack.py
│   └── dns_stack.py
├── scripts/traffic_switch.py
└── tests/test_stacks.py

Elastic Beanstalk Path

1. Create infra/ Directory

In app monorepo (or separate repo):

mkdir -p infra/stacks infra/scripts infra/tests infra/lambda

2. Initialize CDK Project

Same venv/CDK setup as EKS path.

Create app.py wiring stacks for your project, e.g.:

• MimirNetwork — VPC lookup, EB security group, RDS ingress
• MimirApp — EB app, {project}-prod / {project}-idle, ECR ref, CI IAM, alarms
• MimirBackups — S3 pre-migrate bucket, SSM on EB instance role
• MimirSes — SES configuration set (if transactional email)
• MimirDns — Route53 CNAME → {project}-prod.eba-… (see DCI-05 EB path)

3. Directory Structure

infra/
├── app.py
├── cdk.json
├── requirements.txt
├── .env.example          ← secrets template (gitignored .env)
├── eb_live_platform_settings.json  ← exported from live EB (no secrets)
├── stacks/
│   ├── network_stack.py
│   ├── app_stack.py      ← EB + ECR + CI IAM
│   ├── backups_stack.py
│   ├── ses_stack.py
│   └── dns_stack.py
├── scripts/
│   ├── export_eb_live_settings.py
│   └── diff_eb_live_vs_cdk.py
├── lambda/route53_cname/ ← idempotent CNAME UPSERT
└── tests/test_stacks.py

4. Two Sources of Truth (EB)

See AWS CDK with Python skill § EB Platform Settings Export.

Infra Makefile (Both Paths)

.PHONY: help synth deploy destroy status test provision

help: ## Show help
    @awk 'BEGIN {FS = ":.*##"} /^[a-zA-Z_-]+:.*?##/ { printf "  %-20s %s\n", $$1, $$2 }' $(MAKEFILE_LIST)

synth: ## Synthesize CDK stacks
    cdk synth

deploy: ## Deploy all stacks
    cdk deploy --all --require-approval never

test: ## Run CDK tests
    python -m pytest tests/ -v

provision: ## Install CDK deps
    pip install -r requirements.txt

EB monorepo: add ##@ Deploy targets to the app Makefile (swap, eb-status, backup) — see EB skill.

Deliverables

• ✅ CDK project initialized with stack placeholders for chosen style
• ✅ Infra Makefile with synth/deploy/test targets
• ✅ EB: .env.example + export/diff scripts scaffolded
• ✅ Committed