tflint VS conftest

‍TFLint is a Terraform linter focused on possible errors, best practices, and style conventions in your Terraform code.

TFlint is a powerful linter for Terraform, designed to catch errors and issues that terraform plan may not detect. As Terraform grows in popularity for infrastructure as code, the need for robust tools to ensure code quality and reliability becomes paramount. TFlint fulfills this need by analyzing Terraform configurations to find problems that are not covered by syntax checks. It checks for things like unsuitable AWS instance types, incorrect IAM policy syntax, and the use of deprecated syntax or features. By integrating TFlint into the development process, users can proactively identify potential problems, improving the stability and efficiency of their infrastructure deployments. This additional layer of validation is crucial for maintaining high standards in complex, cloud-based infrastructures.

Looking at the description, https://github.com/terraform-linters/tflint , I think it's not what I am looking for. The reason I used a different tcp port is to make the health check on load balancer fail. It's also the same as not changing the tcp port but developer making a code change in their javascript, nodejs, java, etc fail to start properly. If that happens, load balancer's health check will fail as well.

TFLint is an open-source infrastructure as code linter tool that helps developers and DevOps teams identify potential issues and errors in their Terraform code by checking the Terraform configuration files for best practices, coding standards, and policy compliance.

Indeed, that is the case, atm. Your comment got me searching a little bit more. It seems that they are planning to implement a flag for small fixes https://github.com/terraform-linters/tflint/issues/266

Sounds like tflint to me!

I created a .tflint.hcl with the following content: https://github.com/terraform-linters/tflint/blob/master/docs/user-guide/config.md (The example)

TFLint: This is a Terraform linter that checks for errors and best practices in your Terraform code. TFLint helps to catch common mistakes, such as variable name clashes, missing required variables, or invalid resource arguments. It also checks for compliance with best practices, such as naming conventions and resource ordering. By using TFLint, you can catch errors early on, which helps to improve the quality of your Terraform code.

tflint: Linter para Terraform, serve para avisar sobre problemas com sintaxe, erros nos principais provedores de nuvem, garantir boas práticas e outras coisas.

I wrote following conftest.dev (OPA), sample policy

name: tf-plan-apply on: pull_request: branches: [ main ] env: TF_VERSION: 1.0.0 CONFTEST_VERSION: 0.28.3 WORKING_DIR: ./ jobs: terraform: name: aws-eureka-pairs-etc-s3 runs-on: ubuntu-latest steps: - name: Checkout uses: actions/checkout@v2 - name: Install conftest run: | wget -O - 'https://github.com/open-policy-agent/conftest/releases/download/v${{ env.CONFTEST_VERSION }}/conftest_${{ env.CONFTEST_VERSION }}_Linux_x86_64.tar.gz' | tar zxvf - ./conftest --version //❶ - name: Setup Terraform uses: hashicorp/setup-terraform@v1 with: terraform_wrapper: false //❷ terraform_version: ${{ env.TF_VERSION }} cli_config_credentials_token: ${{ secrets.YOUR_CRED_NAME}} - name: Terraform Init ${{ env.WORKING_DIR }} working-directory: ${{ env.WORKING_DIR }} run: terraform init - name: Terraform Plan ${{ env.WORKING_DIR }} if: github.event_name == 'pull_request' env: GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }} working-directory: ${{ env.WORKING_DIR }} id: plan run: terraform plan -out=tfplan -no-color -lock=false -parallelism=50 - name: Convert terraform plan result to json formmat if: github.event_name == 'pull_request' id: convert working-directory: ${{ env.WORKING_DIR }} run: terraform show -json tfplan > tfplan.json - name: conftest test if: github.event_name == 'pull_request' id: conftest run: ./conftest test --no-color ${{ env.WORKING_DIR }}/tfplan.json //❸

Workload configuration should be audited regularly (Kics, Kubeaudit, Kubescape, Conftest, Kubesec, Checkov)

Insert Conftest! As they state in their GitHub description, Conftest tests against structured configuration data using the Open Policy Agent Rego query language. In the case of Terraform, this means we're actually running unit tests against sample JSON and actual tests against the Terraform state JSON.

While Rego is the policy language we use to assemble our policies, we still need something to run those policies with. If you have a cluster and you want to actively evaluate policies, you can end up running an instance of Open Policy Agent and it's associated tooling. However in our case, we just want to check things at runtime (or just on some recurring basis such as when changes get checked in or a pull request is submitted). In the latter instance, we are able to use another tool from the Open Policy Agent project called ConfTest. What ConfTest allows us to do is to specify a file or directory of files that we want to inspect along with the set of policies we want to inspect them with. It then takes all of that and dumps out the associated outputs from those policies and tell us the results (i.e. the messages, how many policies were checked and the results of those policies). This tool is much better suited for our use case, so this is what we will proceed with. To grab the latest version of ConfTest, you can grab the latest release from here.

OR HOW TO RUN https://github.com/open-policy-agent/conftest AS CI/CD in Circle CI to apply policies?

If you like terraform-compliance, Conftest might also be worth having a look. It has its own DSL to write policies, and allows you to test multiple frameworks. We found this blog post from Lennard Eijsackers very informative, and would thus rather recommend you to check it out.

Can Gatekeeper and Conftest single-source the same set of rules? I'm looking at https://github.com/open-policy-agent/conftest/issues/54#issuecomment-528988831 and not seeing how.