monocdk-nag 1.6.1

Check CDK applications for best practices using a combination on available rule packs.

cdk-nag

Language	cdk-nag	monocdk-nag
Python
TypeScript

• If your project uses cdk version 1.x.x use cdk-nag ^1.0.0
• If your project uses cdk version 2.x.x use cdk-nag ^2.0.0
• If your project uses monocdk use monocdk-nag ^1.0.0

Check CDK applications or CloudFormation templates for best practices using a combination of available rule packs. Inspired by cfn_nag

Available Packs

See RULES for more information on all the available packs.

1. AWS Solutions
2. HIPAA Security
3. NIST 800-53 rev 4
4. NIST 800-53 rev 5
5. PCI DSS 3.2.1

Read the NagPack developer docs if you are interested in creating your own pack.

Usage

For a full list of options See NagPackProps in the API.md

cdk

import { App, Aspects } from '@aws-cdk/core';
import { CdkTestStack } from '../lib/cdk-test-stack';
import { AwsSolutionsChecks } from 'cdk-nag';

const app = new App();
new CdkTestStack(app, 'CdkNagDemo');
// Simple rule informational messages
Aspects.of(app).add(new AwsSolutionsChecks());
// Additional explanations on the purpose of triggered rules
// Aspects.of(stack).add(new AwsSolutionsChecks({ verbose: true }));

cdk v2

import { App, Aspects } from 'aws-cdk-lib';
import { CdkTestStack } from '../lib/cdk-test-stack';
import { AwsSolutionsChecks } from 'cdk-nag';

const app = new App();
new CdkTestStack(app, 'CdkNagDemo');
// Simple rule informational messages
Aspects.of(app).add(new AwsSolutionsChecks());
// Additional explanations on the purpose of triggered rules
// Aspects.of(stack).add(new AwsSolutionsChecks({ verbose: true }));

monocdk

import { App, Aspects } from 'monocdk';
import { CdkTestStack } from '../lib/my-stack';
import { AwsSolutionsChecks } from 'monocdk-nag';

const app = new App();
new CdkTestStack(app, 'CdkNagDemo');
// Simple rule informational messages
Aspects.of(app).add(new AwsSolutionsChecks());
// Additional explanations on the purpose of triggered rules
// Aspects.of(stack).add(new AwsSolutionsChecks({ verbose: true }));

Suppressing a Rule

Example 1) Default Construct

import { SecurityGroup, Vpc, Peer, Port } from '@aws-cdk/aws-ec2';
import { Construct, Stack, StackProps } from '@aws-cdk/core';
import { NagSuppressions } from 'cdk-nag';

export class CdkTestStack extends Stack {
  constructor(scope: Construct, id: string, props?: StackProps) {
    super(scope, id, props);
    const test = new SecurityGroup(this, 'test', {
      vpc: new Vpc(this, 'vpc'),
    });
    test.addIngressRule(Peer.anyIpv4(), Port.allTraffic());
    NagSuppressions.addResourceSuppressions(test, [
      { id: 'AwsSolutions-EC23', reason: 'lorem ipsum' },
    ]);
  }
}

Example 2) Child Constructs

import { User, PolicyStatement } from '@aws-cdk/aws-iam';
import { Construct, Stack, StackProps } from '@aws-cdk/core';
import { NagSuppressions } from 'cdk-nag';

export class CdkTestStack extends Stack {
  constructor(scope: Construct, id: string, props?: StackProps) {
    super(scope, id, props);
    const user = new User(this, 'rUser');
    user.addToPolicy(
      new PolicyStatement({
        actions: ['s3:PutObject'],
        resources: ['arn:aws:s3:::bucket_name/*'],
      })
    );
    // Enable adding suppressions to child constructs
    NagSuppressions.addResourceSuppressions(
      user,
      [{ id: 'AwsSolutions-IAM5', reason: 'lorem ipsum' }],
      true
    );
  }
}

Example 3) Stack Level

import { App, Aspects } from '@aws-cdk/core';
import { CdkTestStack } from '../lib/cdk-test-stack';
import { AwsSolutionsChecks, NagSuppressions } from 'cdk-nag';

const app = new App();
const stack = new CdkTestStack(app, 'CdkNagDemo');
Aspects.of(app).add(new AwsSolutionsChecks());
NagSuppressions.addStackSuppressions(stack, [
  { id: 'AwsSolutions-EC23', reason: 'lorem ipsum' },
]);

Example 4) Construct path

If you received the following error on synth/deploy

[Error at /StackName/Custom::CDKBucketDeployment8675309/ServiceRole/Resource] AwsSolutions-IAM4: The IAM user, role, or group uses AWS managed policies

import { Bucket } from '@aws-cdk/aws-s3';
import { BucketDeployment } from '@aws-cdk/aws-s3-deployment';
import { NagSuppressions } from 'cdk-nag';
import { Construct, Stack, StackProps } from '@aws-cdk/core';

export class CdkTestStack extends Stack {
  constructor(scope: Construct, id: string, props?: StackProps) {
    super(scope, id, props);
    new BucketDeployment(this, 'rDeployment', {
      sources: [],
      destinationBucket: Bucket.fromBucketName(this, 'rBucket', 'foo'),
    });
    NagSuppressions.addResourceSuppressionsByPath(
      this,
      '/StackName/Custom::CDKBucketDeployment8675309/ServiceRole/Resource',
      [{ id: 'AwsSolutions-IAM4', reason: 'at least 10 characters' }]
    );
  }
}

Rules and Property Overrides

In some cases L2 Constructs do not have a native option to remediate an issue and must be fixed via Raw Overrides. Since raw overrides take place after template synthesis these fixes are not caught by the cdk_nag. In this case you should remediate the issue and suppress the issue like in the following example.

Example) Property Overrides

import {
  Instance,
  InstanceType,
  InstanceClass,
  MachineImage,
  Vpc,
  CfnInstance,
} from '@aws-cdk/aws-ec2';
import { Construct, Stack, StackProps } from '@aws-cdk/core';
import { NagSuppressions } from 'cdk-nag';

export class CdkTestStack extends Stack {
  constructor(scope: Construct, id: string, props?: StackProps) {
    super(scope, id, props);
    const instance = new Instance(this, 'rInstance', {
      vpc: new Vpc(this, 'rVpc'),
      instanceType: new InstanceType(InstanceClass.T3),
      machineImage: MachineImage.latestAmazonLinux(),
    });
    const cfnIns = instance.node.defaultChild as CfnInstance;
    cfnIns.addPropertyOverride('DisableApiTermination', true);
    NagSuppressions.addResourceSuppressions(instance, [
      {
        id: 'AwsSolutions-EC29',
        reason: 'Remediated through property override.',
      },
    ]);
  }
}

Using on CloudFormation templates

You can use cdk-nag on existing CloudFormation templates by using the cloudformation-include module.

Example) CloudFormation template with suppression

Sample CloudFormation template with suppression

{
  "Resources": {
    "rBucket": {
      "Type": "AWS::S3::Bucket",
      "Properties": {
        "BucketName": "some-bucket-name"
      },
      "Metadata": {
        "cdk_nag": {
          "rules_to_suppress": [
            {
              "id": "AwsSolutions-S1",
              "reason": "at least 10 characters"
            }
          ]
        }
      }
    }
  }
}

Sample App

import { App, Aspects } from '@aws-cdk/core';
import { CdkTestStack } from '../lib/cdk-test-stack';
import { AwsSolutionsChecks } from 'cdk-nag';

const app = new App();
new CdkTestStack(app, 'CdkNagDemo');
Aspects.of(app).add(new AwsSolutionsChecks());

Sample Stack with imported template

import { CfnInclude } from '@aws-cdk/cloudformation-include';
import { NagSuppressions } from 'cdk-nag';
import { Construct, Stack, StackProps } from '@aws-cdk/core';

export class CdkTestStack extends Stack {
  constructor(scope: Construct, id: string, props?: StackProps) {
    super(scope, id, props);
    new CfnInclude(this, 'Template', {
      templateFile: 'my-template.json',
    });
    // Add any additional suppressions
    NagSuppressions.addResourceSuppressionsByPath(
      this,
      '/CdkNagDemo/Template/rBucket',
      [
        {
          id: 'AwsSolutions-S2',
          reason: 'at least 10 characters',
        },
      ]
    );
  }
}

Contributing

See CONTRIBUTING for more information.

License

This project is licensed under the Apache-2.0 License.