.github/.github/workflows/cd-sam.yaml

name: CD — SAM Deploy

on:
  workflow_call:
    inputs:
      python-version:
        description: "Python version to use"
        type: string
        default: "3.12"
      stack-name:
        description: "CloudFormation stack name"
        type: string
        required: true
      sam-template:
        description: "Path to SAM template file"
        type: string
        default: "template.yaml"
      region:
        description: "AWS region"
        type: string
        default: "us-east-1"
      cfn-role-arn:
        description: "CloudFormation execution role ARN"
        type: string
        required: true
    secrets:
      deploy-role-arn:
        description: "OIDC deploy role ARN"
        required: true
      parameter-overrides:
        description: "SAM parameter overrides (e.g. 'Key1=Value1 Key2=Value2')"
        required: false

permissions:
  id-token: write
  contents: read

jobs:
  deploy:
    runs-on: ubuntu-latest
    timeout-minutes: 15
    # Serialise per stack so two pushes cannot deploy over each other.
    # stack-name is required and region always defaults, so the group is never
    # empty; the pair is exactly what identifies a CloudFormation stack, so
    # different stacks in the same caller repo still deploy in parallel.
    # cancel-in-progress is FALSE on purpose: unlike CI, aborting midway can
    # leave a stack mid-update.
    concurrency:
      group: cd-sam-${{ inputs.region }}-${{ inputs.stack-name }}
      cancel-in-progress: false
    steps:
      - uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1

      - uses: actions/setup-python@5fda3b95a4ea91299a34e894583c3862153e4b97 # v7.0.0
        with:
          python-version: ${{ inputs.python-version }}

      - uses: aws-actions/setup-sam@89ddb14d60e682855e3fea4be85b3c56485de310 # v3.0.0

      - uses: aws-actions/configure-aws-credentials@cbe3b392738ccf3f987d68400dafcf4b0624a56c # v6.2.4
        with:
          role-to-assume: ${{ secrets.deploy-role-arn }}
          aws-region: ${{ inputs.region }}

      - name: Pre-flight checks
        run: |
          echo "Pre-flight: checking stack ${{ inputs.stack-name }}..."
          STATUS=$(aws cloudformation describe-stacks \
            --stack-name "${{ inputs.stack-name }}" \
            --query 'Stacks[0].StackStatus' --output text 2>/dev/null || echo "NOT_FOUND")
          case "$STATUS" in
            ROLLBACK_COMPLETE|*FAILED)
              echo "::error::Stack ${{ inputs.stack-name }} is in $STATUS — manual intervention required."
              exit 1
              ;;
            *IN_PROGRESS)
              echo "::error::Stack ${{ inputs.stack-name }} has an operation in progress ($STATUS) — wait for it to complete."
              exit 1
              ;;
            NOT_FOUND)
              echo "Pre-flight: stack not found — will be created on first deploy."
              ;;
            *)
              echo "Pre-flight: stack status is $STATUS — OK to deploy."
              ;;
          esac

      - name: SAM build
        run: sam build --template ${{ inputs.sam-template }}

      - name: SAM deploy
        # Env-var indirection (not inline expression interpolation) so shell
        # metacharacters in the secret are never parsed as script; unquoted
        # $PARAM_OVERRIDES deliberately word-splits multiple Key=Value pairs.
        env:
          PARAM_OVERRIDES: ${{ secrets.parameter-overrides }}
        run: |
          PARAMS=""
          if [ -n "$PARAM_OVERRIDES" ]; then
            PARAMS="--parameter-overrides $PARAM_OVERRIDES"
          fi
          # $PARAMS is deliberately unquoted: it is either empty (no overrides,
          # so no flag at all) or "--parameter-overrides Key=Value [Key=Value…]",
          # which must reach `sam deploy` as separate argv entries. Quoting it
          # would pass one empty or one concatenated argument and break every
          # parameterised deploy.
          # shellcheck disable=SC2086
          sam deploy \
            --stack-name ${{ inputs.stack-name }} \
            --template-file .aws-sam/build/template.yaml \
            --resolve-s3 \
            --capabilities CAPABILITY_IAM \
            --no-confirm-changeset \
            --no-fail-on-empty-changeset \
            --role-arn ${{ inputs.cfn-role-arn }} \
            $PARAMS

      - name: Post-deploy health check
        run: |
          echo "Health check: verifying stack ${{ inputs.stack-name }}..."

          STATUS=$(aws cloudformation describe-stacks \
            --stack-name "${{ inputs.stack-name }}" \
            --query 'Stacks[0].StackStatus' --output text)
          if [[ "$STATUS" != *"COMPLETE" ]] || [[ "$STATUS" == *"ROLLBACK"* ]]; then
            echo "::error::Stack ${{ inputs.stack-name }} ended in $STATUS after deploy."
            exit 1
          fi
          echo "Stack status: $STATUS"

          echo "Stack outputs:"
          aws cloudformation describe-stacks \
            --stack-name "${{ inputs.stack-name }}" \
            --query 'Stacks[0].Outputs[*].[OutputKey,OutputValue]' --output table

          # Run project-specific health check if it exists
          if [[ -f scripts/health-check.sh ]]; then
            echo "Running project health check..."
            bash scripts/health-check.sh "${{ inputs.stack-name }}" "${{ inputs.region }}"
          fi

          echo "Health check passed."