enhancements VS conftest

The motivation is more the latter, but it's not at all clear the proposed removal of the embedded kustomize will proceed, given the compatibility implications. See discussion at https://github.com/kubernetes/enhancements/issues/4706#issue... and following.

(I do see there are some proposed enhancements related to profiles that might help here)

Thanks for these links!

I picked out one at random just to check if my skeptical reaction is fair: https://github.com/kubernetes/enhancements/tree/master/keps/...

- OK, this is actually a really good and useful doc!

- However, it's not an up-front design doc, it has clearly been written after the bulk of the work has been done, to explain and justify rolling out a big change. (See the "implementation history" timeline: https://github.com/kubernetes/enhancements/tree/master/keps/...)

- It looks like the template wasn't very useful; most of the required sections are marked "N/A", and there are comments like The best test for work like this is, more or less, "did it work?"

> was always told early on that although they supported vault on kubernetes via a helm chart, they did not recommend using it on anything but EC2 instances (because of "security" which never really made sense their reasoning).

The reasoning is basically that there are some security and isolation guarantees you don't get in Kubernetes that you do get on bare metal or (to a somewhat lesser extent) in VMs.

In particular for Kubernetes, Vault wants to run as a non-root user and set the IPC_LOCK capability when it starts to prevent its memory from being swapped to disk. While in Docker you can directly enable this by adding capabilities when you launch the container, Kubernetes has an issue because of the way it handles non-root container users specified in a pod manifest, detailed in a (long-dormant) KEP: https://github.com/kubernetes/enhancements/blob/master/keps/... (tl;dr: Kubernetes runs the container process as root, with the specified capabilities added, but then switches it to the non-root UID, which causes the explicitly-added capabilities to be dropped).

You can work around this by rebuilding the container and setting the capability directly on the binary, but the upstream build of the binary and the one in the container image don't come with that set (because the user should set it at runtime if running the container image directly, and the systemd unit sets it via systemd if running as a systemd service, so there's no need to do that except for working around Kubernetes' ambient-capability issue).

> It always surprised me how these conversations went. "Well we don't really recommend kubernetes so we won't support (feature)."

0 is not the request we've defined. And that makes sense. Memory QoS has been in alpha since Kubernetes 1.22 (August 2021) and according to the KEP data was still in alpha as of 1.27.

Note: There's actually a Structured Authentication Config established via KEP-3331. It's in v1.28 as a feature flag gated option and removes the limitation of only having one OIDC provider. I may look into doing an article on it, but for now I'll deal with the issue in a manner that should work even with a bit older versions versions of Kubernetes.

Kubernetes supports a skew policy of n+2 between API server and kubelet. This means if your CP and DP are both on 1.20, you could upgrade your control plane twice (1.20 -> 1.21 -> 1.22) before you need to upgrade your data plane. And when it comes time to upgrade your data plane you can jump from 1.20 to 1.22 to minimize update churn. In the future, this skew will be opened to n+3 https://github.com/kubernetes/enhancements/tree/master/keps/sig-architecture/3935-oldest-node-newest-control-plane

The KEP (Kubernetes Enhancement Proposal) is linked to in the PR [1]. From the summary:

> Sidecar containers are a new type of containers that start among the Init containers, run through the lifecycle of the Pod and don’t block pod termination. Kubelet makes a best effort to keep them alive and running while other containers are running.

[1] https://github.com/kubernetes/enhancements/tree/master/keps/...

This is where the new feature of mutable scheduling directives for jobs comes into play. This feature enables the updating of a job's scheduling directives before it begins. Essentially, it allows custom queue controllers to influence pod placement without needing to directly handle the assignment of pods to nodes themselves. To learn more about this check out the Kubernetes Enhancement Proposal 2926.

What your asking is a (vanilla) Kubernetes non-goal, others have mentioned fluxcd and other add ons that provide primitives for dependency aware deployments. The problem space is so large, that it's unreasonable to to address these concerns in Kubernetes itself, instead, make it extensible... Look at this KEP for example: https://github.com/kubernetes/enhancements/issues/753 Sidecar containers have existed, and been named as such since WAY before that KEP's inception, defining what these things should and shouldn't do is largely arbitrary. Aka: your use-case is niche, if you don't like the behavior, use flux or argo, or write something yourself.

6 - https://github.com/open-policy-agent/conftest

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.