distribution VS OPA (Open Policy Agent)

To transfer the image between your local machine and the server, you'll need a registry such as Docker Hub or GitHub Container Registry. (Technically you can compress images and distribute them as files but it's more of a headache than it's worth) There are plenty of registries that will allow you to host private images if that's a concern for you, but it will be harder to find a free/cheap solution. You can also host your own registry using the Distribution Project. But be warned that while hosting a basic registry is really easy, locking it down can be a pain because of the lack of well maintained and easy to use projects.

The open source repository my colleague and I reference in this talk can be seen at https://github.com/distribution/distribution/

FWIW, the open source registry application itself is essentially stateless. You just run multiple copies of it and point all of them at the same storage for a High Availability setup. If you have GlusterFS, you can mount it to the local filesystem and use the filesystem storage driver, though you may need to tweak settings for it to function properly (example).

It's always been one of those items deep down on the "to consider" list, and my rationale was that there really aren't any straight-forward solutions for this and with Gitlab and Github offering their own registries it was never a problem.

But yesterday I found out that Docker's Registry core (Distribution) [0] is OpenSource (and used by other registries too!), but I haven't seen many mentions of it until then. I've checked out their documentation and it seems solid.

So, what is your experience with self-hosting registries be it Distribution, Harbour or something else. Any hidden PITA? I myself will spin Distribution up on the dev env and see how it goes!

[0]: https://github.com/distribution/distribution

The original registry "distribution" project (which is the base of Docker Hub, Harbor, etc) was donated to the CNCF: https://github.com/distribution/distribution

Evaluated this a couple of weeks back. Ended up going for registry:2 aka distribution/distribution + https://github.com/cesanta/docker_auth + https://github.com/Quiq/docker-registry-ui

> There's a standards conversion going on where we can trace the provenance of each and every layer of the image, we can start signing those layers, and with that metadata, we can start doing automated decisioning, automated reporting, automated visibility into what's been done to that image at each step of the lifecycle.

Docker's CEO is being disingenuous. When you deploy a Docker container, you specify the image ID. The ID looks like a SHA-256 digest and even starts with the string 'sha256' but it is an arbitrary value generated by the docker daemon on the local machine. The ID is not a hash of the image contents [0]. In other words, docker images are not content-addressed.

Since docker images are not content-addressed, your image registry and image transfer tools can subvert the security of your production systems. The fix is straightforward: make an image ID be the SHA-256 digest of the image contents, which is the same everywhere: on your build system, image registry, test system, and production hosts. This fix will increase supply chain security for all Docker users. It is massive low-hanging fruit.

Now Docker will add image signatures without first making images content-addressed. Their decision makes sense only if their goal is to make money and not make a secure product. I cannot trust a company with such priorities.

[0] https://github.com/distribution/distribution/issues/1662

no docker distribution please, https://github.com/distribution/distribution seems hard to run and config.

I’ve not used it myself but it does look like the Docker registry itself is open source https://docs.docker.com/registry/deploying/ and https://github.com/distribution/distribution

How can we handle this? Are there any mechanisms to prevent or at least to some extent safeguard this kind of issues without falling back to a manual workflow? There is. One huge advantage of sticking to (de-facto) standards like Terraform is that first we are probably not the first ones to come up with this question and second there is a huge ecosystem around Terraform that might help us with such challenges. And for this specific scenario the solution is the Open Policy Agent. Let us take a closer look how the solution could look like.

A popular Policy-as-Code tool for Terraform is OPA, everyone's favorite versatile open-source policy engine that enforces security and compliance policies across your cloud-native stack, making it easier to manage and maintain consistent policy enforcement in complex, multi-service environments.

Harness Policy As Code uses Open Policy Agent (OPA) as the central service to store and enforce policies for the different entities and processes across the Harness platform. In this section, you will define a policy that will deny a pipeline execution if there is no approval step defined in a deployment stage.

OPA: While OPA is an open-source, general-purpose policy engine capable of enforcing unified and context-aware policies throughout the stack, it can also accept and output data in formats such as JSON, effectively functioning as a tool for generating or modifying configurations. Although it does not provide out-of-the-box schema definition support, it allows the integration of JsonSchema definitions.

In essence, container image signing involves adding a digital stamp to an image, affirming its authenticity. This digital assurance guarantees that the image is unchanged from creation to deployment. In this blog, I'll explain how to sign container images for Kubernetes using Cosign and the Open Policy Agent. I will also share a tutorial that demonstrates these concepts.

In this post we will explores two powerful solutions for addressing this issue: the Open Policy Language (OPA) and Google’s Zanzibar.

Rego is a declarative query language from the makers of the Open Policy Agent (OPA) framework. The Cloud Native Computing Foundation (CNCF) accepted OPA as an incubation-level hosted project in April 2019, and OPA graduated from incubating status in 2021.

Now there are more subdivided practice: * Policy as Code: Sentinel, OPA * Database as Code: bytebase * AppConfiguration as Code: KusionStack, Acorn * ...... (Welcome to add more)