gatekeeper-library VS gvisor

Here is a library or rules for the Open Policy Agent.

https://github.com/open-policy-agent/gatekeeper-library is the library of OPA Gatekeeper policies.

Many more examples are available in the OPA Gatekeeper library project!

by default and exposes metrics on path ```/metrics``` . It can run locally on your development box as long as you have a valid Kubernetes configuration in your home folder (i.e. if you can run kubectl and have the right permissions). When running on the cluster a ```incluster``` parameter is passed in so that it knows where to look up for the cluster credentials. Exporter program connects to Kubernetes API every 10 seconds to scrape data from Kubernetes API. We've used [this](https://medium.com/teamzerolabs/15-steps-to-write-an-application-prometheus-exporter-in-go-9746b4520e26) blog post as the base for the code. ## Demo Let's go ahead and prepare our components so that we have a Grafana dashboard to show us which constraints have been violated and how the number of violations evolve over time. ### 0) Required tools - [Git](https://git-scm.com/downloads): A git cli is required to checkout the repo and - [Kubectl](https://kubernetes.io/docs/tasks/tools/) and a working K8S cluster - [Ytt](https://carvel.dev/ytt/): This is a very powerful yaml templating tool, in our setup it's used for dynamically overlaying a key/value pair in all constraints. It's similar to Kustomize, it's more flexibel than Kustomize and heavily used in some [Tanzu](https://tanzu.vmware.com/tanzu) products. - [Kustomize](https://kustomize.io/): Gatekeeper-library relies on Kustomize, so we need it too. - [Helm](https://helm.sh/): We will install Prometheus and Grafana using helm - Optional: [Docker](https://www.docker.com/products/docker-desktop): Docker is only optional as we already publish the required image on dockerhub. ### 1) Git submodule update Run ```git submodule update --init``` to download gatekeeper-library dependency. This command will download the [gatekeeper-library](https://github.com/open-policy-agent/gatekeeper-library) dependency into folder ```gatekeeper-library/library``` . ### 2) Install OPA/Gatekeeper If your K8S cluster does not come with Gatekeeper preinstalled, you can use install it as explained [here](https://open-policy-agent.github.io/gatekeeper/website/docs/install/). If you are familiar with helm, the easiest way to install is as follows: ```bash helm repo add gatekeeper https://open-policy-agent.github.io/gatekeeper/charts helm install gatekeeper/gatekeeper --generate-name

Gatekeeper library has example policies for restricting image repositories: https://github.com/open-policy-agent/gatekeeper-library/tree/master/library/general

You should check out the Gatekeeper project. There's plenty of templates available for use without having to write a single line of rego for most use cases (e.g https://github.com/open-policy-agent/gatekeeper-library)

Isn't gVisor kind of this as well?

"gVisor is an application kernel for containers. It limits the host kernel surface accessible to the application while still giving the application access to all the features it expects. Unlike most kernels, gVisor does not assume or require a fixed set of physical resources; instead, it leverages existing host kernel functionality and runs as a normal process. In other words, gVisor implements Linux by way of Linux."

https://github.com/google/gvisor

This sort of feels like seeing someone riding a bike and saying: why don’t they just get a car? The simple fact is that containers and VMs are quite different. Whether something uses VMX and friends or not is also a red herring, as gVisor also “rolls it own VMM” [1].

[1] https://github.com/google/gvisor/tree/master/pkg/sentry/plat...

There's two major production-ready Go-based operating system(-ish) projects:

- Google's gVisor[1] (a re-implementation of a significant subset of the Linux syscall ABI for isolation, also mentioned in the article)

- USBArmory's Tamago[2] (a single-threaded bare-metal Go runtime for SOCs)

Both of these are security-focused with a clear trade off: sacrifice some performance for memory safe and excellent readability (and auditability). I feel like that's the sweet spot for low-level Go - projects that need memory safety but would rather trade some performance for simplicity.

[1]: https://github.com/google/gvisor

[2]: https://github.com/usbarmory/tamago

It uses gVisor to create a TCP/IP stack in userspace, and starts a wireguard interface on it, which the HTTP server from http.Serve listens on. The library will print a URL after startup, where you can access your server. You can create multiple listeners in one binary.

The playground compiles the program with GOOS=linux, GOARCH=amd64 and runs the program with gVisor. Detailed documentation is available at the gVisor site.

You could use a container sandbox like gVisor, light virtual machines as containers (Kata containers, firecracker + containerd) or full virtual machines (virtlet as a CRI).