Ory Oathkeeper VS OPA (Open Policy Agent)

Hydra feels mature. I think it's their longest-developed product so far. Besides breaking changes during big upgrades(v0 -> v1beta -> v1), everything has been painless:

- It runs anywhere with or without containers

- API makes sense, good SDKs are available in all my used languages

- RAM usage is surprisingly low compared to usage and has been great for resource-constrained environments

- Stateless means horizontal scaling is as easy as `replicas++`

- Sub-millisecond response times for some calls, much faster than our previous setup

With Hydra, I know it's the client's fault when OAuth calls fail and not just a buggy server implementation. This is reinforced in dev mode with great errors like:

- The authorization code has already been used

- The request is missing the response_type parameter

- Parameter "nonce" must be set when using the implicit flow

- Redirect URL "https://example.com/callback" does not match

On the flipside, Oathkeeper is not a mature product and has not yet reached v1. There are breaking changes planned [1]. It lacks support for at least one popular usecase (mine) out of the box [2]. Rules can be hard to create and debug. I wouldn't recommend Oathkeeper in its current state unless you're ready to dive in and fix things yourself. Once configured it sticks with the Ory trend: fast, lean, and stable.

Depending on your usecase, Oathkeeper could be swapped out with any IAP like Pomerium or just with your reverse proxy's auth request support + some small custom shim.

I haven't tried Keto (access control) or Kratos (user management) yet. Kratos is on my todo list.

[1] https://github.com/ory/oathkeeper/issues/441

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)