DevOps Meetup: pre-commit hooks + IaC Static Code Analysis Tools

This document contains instructions on configuring the pre-commit framework for this repository, with contain numerous terraform code examples.

Also, we will explore two open-sorce, community-driven static code analysis tool for scanning infrastructure as code (IaC) files for misconfigurations called Checkov and Terrascan.

This repository is a fork from alfonsof/terraform-azure-examples.

First things first!

Clone the repo

$ gh repo clone danielbmeireles/dvm-pre-commit

Set the default remote repo

$ gh repo set-default

This command sets the default remote repository to use when querying the
GitHub API for the locally cloned repository.

gh uses the default repository for things like:

 - viewing and creating pull requests
 - viewing and creating issues
 - viewing and creating releases
 - working with GitHub Actions
 - adding repository and environment secrets

? Which repository should be the default? danielbmeireles/dvm-pre-commit
✓ Set danielbmeireles/dvm-pre-commit as the default repository for the current directory

Inspect the pre-commit config file

$ yq .pre-commit-config.yaml

Can you identify the three main sections of the file? How many repos are configured? And how many hooks?

Install the hooks

$ pre-commit install --install-hooks

Update the hooks

$ pre-commit autoupdate

Does any repository was updated?

Playing with the pre-commit command

Manually run pre-commit hooks

At any time, you can manually run all pre‑commit hooks in a repository. For example, following some code modifications but prior to committing your changes, you can run the hooks to reveal any identified issues beforehand. Just run the following command:

$ pre-commit run

Bear in mind that this checks only for files added with git add.

Running an individual hook by referring its ID

$ pre-commit run terraform-fmt

Check all files in the repo

If you want to check all files in the re­pository, regardless of their state in the Git database, add the ‑‑all‑files argument:

$ pre-commit run --all-files

This is always a good idea after adding a new hook. You can also combine this with the restriction to an individual hook:

$ pre-commit run terraform-fmt --all-files

Skipping a failed hook

$ SKIP=checkov git commit ‑m "Add foo"

Skipping multiple hooks

$ SKIP=checkov,terrascan git commit ‑m "Add foo"

Skipping all hooks

$ git commit ‑m "Add foo" ‑‑no‑verify

Playing with the checkov command

Select a single file and scan

$ checkov -f main.tf

Select input folder and scan

$ checkov -d /user/tf

Playing with the terrascan command

Initializing Terrascan

$ terrascan init

Note: The init command is implicitly executed if the scan command does not find policies while executing.

Terrascanning

$ terrascan scan

Terrascanning current directory containing terraform files for AWS Resources

$ terrascan scan -t aws

Try to execute the same command but using the azure cloud provider.

Terrascanning for a specific IaC provider

$ terrascan scan -i terraform

Remote terrascanning

$ terrascan scan -t azure -r git -u git@github.com:danielbmeireles/dvm-pre-commit.git//code/01-hello-world