conftest VS sealed-secrets

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.

If you have noticed, you are setting secrets in plain text on the application-configmap.yml file, which is not ideal and is not a best practice for security. The best way to do this securely would be to use AWS Secrets Manager, an external service like HashiCorp Vault, or Sealed Secrets. To learn more about these methods see the blog post Shhhh... Kubernetes Secrets Are Not Really Secret!.

Yeah documentation is hard and I'm guilty (as a former maintainer of SealedSecrets)

SealedSecrets was designed with "write only" secrets in mind.

Turns out a lot of people need to access the current secrets because they need to update a part of a "composite" secret.

There are two kinds of "composite" secrets, one easy and one harder, but if you don't know how to do it, even the easier is hard:

1. Secret with multiple data "items" (also called keys in K8s Secret jargon but that's confusing when there is encryption involved). I.e. good old "data":{"foo": "....", "bar": "..."}

2. Secrets where data within one item is actually a config file with cleartext and secrets mixed up in one single string (usually some JSON or YAML or TOML)

Case 1 is "easy" to deal with once you realize that sealed secrets files are just text files and you can just manually merge and update encryoted data items. We even created a "merge" and some "raw" encryption APIs to make that process a little less "copy pasta" but it's still hard to have a good UX that works for everyone.

Case 2 is harder. We did implement a data templating feature that allows you to generate a config file via a go-template that keeps the cleartext parts in clear and uses templating directives to inject the secret parts where you want (referencing the encrypted the items)

The main problem with case 2 is that it's undocumented.

The feature landed in 2021:

https://github.com/bitnami-labs/sealed-secrets/pull/580

I noticed that people at my current $dayjob used sealed secrets for years and it took me a while to understand that the reason they hated it was that they didn't know about that fundamental feature.

And how to blame them!? It's still undocumented!

In my defense I spent so much effort before and after I left VMware to lobby so that the project got the necessary staffing so it wouldn't die of bitrot that I didn't have much time left to work on documentation. Which is a bit said and probably just an excuse :-)

That said, I'm happy that the project is alive and the current maintainers are taking care of it against the forces of entropy. Perhaps some doc work would be useful too. Unfortunately I don't have time for now.

This might be OT, and forgive me, but I think one of the best practices for Encrypting and Managing secrets in Kubernetes is to use Sealed Secrets, they allow your secrets to be securely stored in git with the rest of the configuration and yet no one with access to the Git repository will be able to read them. I say this might be OT, because Sealed Secrets are trying to mitigate a different threat, the threat of the secrets at rest somewhere, and not "live in the cluster", where in theory all the ingredients to decrypt the secrets would still live.

The addition of Consul and Vault gives me a few things. For one, right now I'm handling secrets with a mixture of SOPS and Sealed Secrets. I use Vault in my professional life, and have used both Vault and Consul at my last job. Vault is a beast, so I may as well get better at it; plus its options for secret injection are better.

Use Sealed Secrets Operator.

sealed-secrets (sealed)

An option that easily works with GitOps is the Operator Sealed Secrets from Bitnami. Secrets encrypted with it can only be decrypted by operators running inside the cluster, not even by the original author. For encryption, there is a CLI (and a third-party web UI) that requires a connection to the cluster. The disadvantage of this is that the key material is stored in the cluster, the secrets are bound to the cluster and one has to take care of backups and operation.