shoc-backend/infra/cdk/deploy-dev-stack.ts

import * as cdk from 'aws-cdk-lib';
import * as iam from 'aws-cdk-lib/aws-iam';
import { Construct } from 'constructs';

const ACCOUNT_ID = '396287094661';
const REGION = 'us-east-1';
const APPLICATION_NAME = 'shoc-backend';
const ENVIRONMENT_NAME = 'shoc-backend-dev';
const REPO = 'Sea-Haven-Industries/shoc-backend';
const BUCKET_NAME = `elasticbeanstalk-${REGION}-${ACCOUNT_ID}`;

export class DeployDevStack extends cdk.Stack {
  constructor(scope: Construct, id: string, props: cdk.StackProps = {}) {
    super(scope, id, props);

    const applicationArn = `arn:aws:elasticbeanstalk:${REGION}:${ACCOUNT_ID}:application/${APPLICATION_NAME}`;
    const environmentArn = `arn:aws:elasticbeanstalk:${REGION}:${ACCOUNT_ID}:environment/${APPLICATION_NAME}/${ENVIRONMENT_NAME}`;
    const bucketArn = `arn:aws:s3:::${BUCKET_NAME}`;
    const oidcProviderArn = `arn:aws:iam::${ACCOUNT_ID}:oidc-provider/token.actions.githubusercontent.com`;

    const deployRole = new iam.Role(this, 'GithubDeployRole', {
      roleName: 'githubdeploy-shoc-backend-dev',
      description:
        'Least-privilege GitHub OIDC deploy role for shoc-backend dev. CDK-owned; application/environment/S3 are owned by Elastic Beanstalk.',
      assumedBy: new iam.FederatedPrincipal(
        oidcProviderArn,
        {
          StringEquals: {
            'token.actions.githubusercontent.com:aud': 'sts.amazonaws.com',
            'token.actions.githubusercontent.com:sub': `repo:${REPO}:environment:dev`,
          },
        },
        'sts:AssumeRoleWithWebIdentity',
      ),
    });

    deployRole.applyRemovalPolicy(cdk.RemovalPolicy.RETAIN);
    const cfnRole = deployRole.node.defaultChild as iam.CfnRole;
    cfnRole.cfnOptions.deletionPolicy = cdk.CfnDeletionPolicy.RETAIN;
    cfnRole.cfnOptions.updateReplacePolicy = cdk.CfnDeletionPolicy.RETAIN;

    deployRole.addToPolicy(
      new iam.PolicyStatement({
        effect: iam.Effect.ALLOW,
        actions: [
          'elasticbeanstalk:DescribeEnvironments',
          'elasticbeanstalk:DescribeApplicationVersions',
          'elasticbeanstalk:DescribeEvents',
        ],
        resources: ['*'],
      }),
    );

    deployRole.addToPolicy(
      new iam.PolicyStatement({
        effect: iam.Effect.ALLOW,
        actions: ['elasticbeanstalk:CreateApplicationVersion'],
        resources: [
          applicationArn,
          `arn:aws:elasticbeanstalk:${REGION}:${ACCOUNT_ID}:applicationversion/${APPLICATION_NAME}/*`,
        ],
      }),
    );

    deployRole.addToPolicy(
      new iam.PolicyStatement({
        effect: iam.Effect.ALLOW,
        actions: ['elasticbeanstalk:UpdateEnvironment'],
        resources: [environmentArn],
      }),
    );

    deployRole.addToPolicy(
      new iam.PolicyStatement({
        effect: iam.Effect.ALLOW,
        actions: ['s3:ListBucket', 's3:CreateBucket'],
        resources: [bucketArn],
      }),
    );

    deployRole.addToPolicy(
      new iam.PolicyStatement({
        effect: iam.Effect.ALLOW,
        actions: ['s3:GetObject', 's3:GetObjectVersion', 's3:PutObject'],
        resources: [`${bucketArn}/${APPLICATION_NAME}/*`],
      }),
    );

    new cdk.CfnOutput(this, 'GithubDeployRoleArn', {
      value: deployRole.roleArn,
      description: 'ARN of the GitHub OIDC deploy role for shoc-backend dev.',
      exportName: 'shoc-backend-deploy-dev-role-arn',
    });
  }
}