Checkov – Prevent Cloud Misconfigurations During Build-Time For Terraform, CloudFormation, Kubernetes, Serverless Framework And Other Infrastructure-As-Code-Languages

Getting started

Requirements

• Python >= 3.7 (Data classes are available for Python 3.7+)
• Terraform >= 0.12

Installation

pip3 install checkov

Installation on Alpine:

pip3 install --upgrade pip && pip3 install --upgrade setuptools
pip3 install checkov

Installation on Ubuntu 18.04 LTS:

Ubuntu 18.04 ships with Python 3.6. Install python 3.7 (from ppa repository)

sudo apt update
sudo apt install software-properties-common
sudo add-apt-repository ppa:deadsnakes/ppa
sudo apt install python3.7
sudo apt install python3-pip
sudo python3.7 -m pip install -U checkov #to install or upgrade checkov)

or using homebrew (MacOS only)

brew install checkov

or

brew upgrade checkov

Enabling bash autocomplete

source <(register-python-argcomplete checkov)

Upgrade

if you installed checkov with pip3

pip3 install -U checkov

Configure an input folder or file

checkov --directory /user/path/to/iac/code

Or a specific file or files

checkov --file /user/tf/example.tf

Or

checkov -f /user/cloudformation/example1.yml -f /user/cloudformation/example2.yml

Or a terraform plan file in json format

terraform init
terraform plan -out tf.plan
terraform show -json tf.plan  > tf.json 
checkov -f tf.json

Note: terraform show output file tf.json will be a single line. For that reason all findings will be reported line number 0 by checkov

check: CKV_AWS_21: "Ensure all data stored in the S3 bucket have versioning enabled"
	FAILED for resource: aws_s3_bucket.customer
	File: /tf/tf.json:0-0
	Guide: https://docs.bridgecrew.io/docs/s3_16-enable-versioning

If you have installed jq you can convert json file into multiple lines with the following command:

terraform show -json tf.plan | jq '.' > tf.json 

Scan result would be much user friendly.

checkov -f tf.json
Check: CKV_AWS_21: "Ensure all data stored in the S3 bucket have versioning enabled"
	FAILED for resource: aws_s3_bucket.customer
	File: /tf/tf1.json:224-268
	Guide: https://docs.bridgecrew.io/docs/s3_16-enable-versioning

		225 |               "values": {
		226 |                 "acceleration_status": "",
		227 |                 "acl": "private",
		228 |                 "arn": "arn:aws:s3:::mybucket",

Alternatively, specify the repo root of the hcl files used to generate the plan file, using the --repo-root-for-plan-enrichment flag, to enrich the output with the appropriate file path, line numbers, and codeblock of the resource(s). An added benefit is that check suppressions will be handled accordingly.

checkov -f tf.json --repo-root-for-plan-enrichment /user/path/to/iac/code

Scan result sample (CLI)

Passed Checks: 1, Failed Checks: 1, Suppressed Checks: 0
Check: "Ensure all data stored in the S3 bucket is securely encrypted at rest"
/main.tf:
	 Passed for resource: aws_s3_bucket.template_bucket 
Check: "Ensure all data stored in the S3 bucket is securely encrypted at rest"
/../regionStack/main.tf:
	 Failed for resource: aws_s3_bucket.sls_deployment_bucket_name       

Start using Checkov by reading the Getting Started page.

Using Docker

docker pull bridgecrew/checkov
docker run --tty --volume /user/tf:/tf bridgecrew/checkov --directory /tf

Note: if you are using Python 3.6(Default version in Ubuntu 18.04) checkov will not work and it will fail with ModuleNotFoundError: No module named 'dataclasses' error message. In this case, you can use the docker version instead.

Note that there are certain cases where redirecting docker run --tty output to a file – for example, if you want to save the Checkov JUnit output to a file – will cause extra control characters to be printed. This can break file parsing. If you encounter this, remove the --tty flag.

Running or skipping checks

Using command line flags you can specify to run only named checks (allow list) or run all checks except those listed (deny list).

List available checks:

checkov --list 

Allow only 2 checks to run:

checkov --directory . --check CKV_AWS_20,CKV_AWS_57

Run all checks except 1 specified:

checkov -d . --skip-check CKV_AWS_20

Run all checks except checks with specified patterns:

checkov -d . --skip-check CKV_AWS*

For Kubernetes workloads, you can also use allow/deny namespaces. For example, do not report any results for the kube-system namespace:

checkov -d . --skip-check kube-system

Suppressing/Ignoring a check

Like any static-analysis tool it is limited by its analysis scope. For example, if a resource is managed manually, or using subsequent configuration management tooling, suppression can be inserted as a simple code annotation.

Suppression comment format

To skip a check on a given Terraform definition block or CloudFormation resource, apply the following comment pattern inside it’s scope:

checkov:skip=<check_id>:<suppression_comment>

• <check_id> is one of the [available check scanners](docs/5.Policy Index/all.md)
• <suppression_comment> is an optional suppression reason to be included in the output

Example

The following comment skips the CKV_AWS_20 check on the resource identified by foo-bucket, where the scan checks if an AWS S3 bucket is private. In the example, the bucket is configured with public read access; Adding the suppress comment would skip the appropriate check instead of the check to fail.

resource "aws_s3_bucket" "foo-bucket" {    region        = var.region      #checkov:skip=CKV_AWS_20:The bucket is a public static content host    bucket        = local.bucket_name    force_destroy = true    acl           = "public-read"  }  

The output would now contain a SKIPPED check result entry:

resource "aws_s3_bucket" "foo-bucket" {
  region        = var.region
    #checkov:skip=CKV_AWS_20:The bucket is a public static content host
  bucket        = local.bucket_name
  force_destroy = true
  acl           = "public-read"
}

To skip multiple checks, add each as a new line.

...
...
Check: "S3 Bucket has an ACL defined which allows public access."
	SKIPPED for resource: aws_s3_bucket.foo-bucket
	Suppress comment: The bucket is a public static content host
	File: /example_skip_acl.tf:1-25

...

To suppress checks in Kubernetes manifests, annotations are used with the following format: checkov.io/skip#: <check_id>=<suppression_comment>

For example:

  #checkov:skip=CKV2_AWS_6
  #checkov:skip=CKV_AWS_20:The bucket is a public static content host

Logging

For detailed logging to stdout set up the environment variable LOG_LEVEL to DEBUG.

Default is LOG_LEVEL=WARNING.

Skipping directories

To skip files or directories, use the argument --skip-path, which can be specified multiple times. This argument accepts regular expressions for paths relative to the current working directory. You can use it to skip entire directories and / or specific files.

By default, all directories named node_modules, .terraform, and .serverless will be skipped, in addition to any files or directories beginning with .. To cancel skipping directories beginning with . override IGNORE_HIDDEN_DIRECTORY_ENV environment variable export IGNORE_HIDDEN_DIRECTORY_ENV=false

You can override the default set of directories to skip by setting the environment variable CKV_IGNORED_DIRECTORIES. Note that if you want to preserve this list and add to it, you must include these values. For example, CKV_IGNORED_DIRECTORIES=mynewdir will skip only that directory, but not the others mentioned above. This variable is legacy functionality; we recommend using the --skip-file flag.

VSCODE Extension

If you want to use checkov’s within vscode, give a try to the vscode extension available at vscode

Configuration using a config file

Checkov can be configured using a YAML configuration file. By default, checkov looks for a .checkov.yaml or .checkov.yml file in the following places in order of precedence:

• Directory against which checkov is run. (--directory)
• Current working directory where checkov is called.
• User’s home directory.

Attention: it is a best practice for checkov configuration file to be loaded from a trusted source composed by a verified identity, so that scanned files, check ids and loaded custom checks are as desired.

Users can also pass in the path to a config file via the command line. In this case, the other config files will be ignored. For example:

apiVersion: v1
kind: Pod
metadata:
  name: mypod
  annotations:
    checkov.io/skip1: CKV_K8S_20=I don't care about Privilege Escalation :-O
    checkov.io/skip2: CKV_K8S_14
    checkov.io/skip3: CKV_K8S_11=I have not set CPU limits as I want BestEffort QoS
spec:
  containers:
...

Users can also create a config file using the --create-config command, which takes the current command line args and writes them out to a given path. For example:

checkov --config-file path/to/config.yaml

Will create a config.yaml file which looks like this:

checkov --compact --directory test-dir --docker-image sample-image --dockerfile-path Dockerfile --download-external-modules True --external-checks-dir sample-dir --no-guide --quiet --repo-id bridgecrew/sample-repo --skip-check CKV_DOCKER_3,CKV_DOCKER_2 --skip-fixes --skip-framework dockerfile secrets --skip-suppressions --soft-fail --branch develop --check CKV_DOCKER_1 --create-config /Users/sample/config.yml

Users can also use the --show-config flag to view all the args and settings and where they came from i.e. commandline, config file, environment variable or default. For example:

branch: develop
check:
  - CKV_DOCKER_1
compact: true
directory:
  - test-dir
docker-image: sample-image
dockerfile-path: Dockerfile
download-external-modules: true 
evaluate-variables: true 
external-checks-dir: 
  - sample-dir 
external-modules-download-path: .external_modules 
framework:
  - all 
no-guide: true 
output: cli 
quiet: true 
repo-id: bridgecrew/sample-repo 
skip-check: 
  - CKV_DOCKER_3 
  - CKV_DOCKER_2 
skip-fixes: true 
skip-framework:
  - dockerfile
  - secrets
skip-suppressions: true 
soft-fail: true

Will display:

checkov --show-config

Contributing

Contribution is welcomed!

Start by reviewing the contribution guidelines. After that, take a look at a good first issue.

Looking to contribute new checks? Learn how to write a new check (AKA policy) here.

Disclaimer

checkov does not save, publish or share with anyone any identifiable customer information.
No identifiable customer information is used to query Bridgecrew’s publicly accessible guides. checkov uses Bridgecrew’s API to enrich the results with links to remediation guides. To skip this API call use the flag --no-guide.

Support

Bridgecrew builds and maintains Checkov to make policy-as-code simple and accessible.

Start with our Documentation for quick tutorials and examples.

If you need direct support you can contact us at [email protected].