Version 2.2

Security Overview

Kf aims to provide a similar developer experience to Cloud Foundry, replicating the build, push, and deploy lifecycle. It does this by building a developer UX layer on top of widely-known, broadly used and adopted technologies like Kubernetes, Istio, and container registries rather than by implementing all the pieces from the ground up.

Security overview

When making security decisions, Kf aims to provide complete solutions that are native to their respective components and can be augmented with other mechanisms. Breaking that down:

  • Complete solutions means that Kf tries not to provide partial solutions that can lead to a false sense of security.
  • Native means that the solutions should be a part of the component rather than a Kf construct to prevent breaking changes.
  • Can be augmented means the approach Kf takes should work seamlessly with other Kubernetes and Google Cloud tooling for defense in depth.

Important considerations

In addition to the Current limitations described below, it is important that you read through and understand the items outlined in this section.

Workload Identity

By default, Kf uses Workload Identity to provide secure delivery and rotation of the Service Account credentials used by Kf to interact with your Cloud project. Workload Identity achieves this by mapping a Kubernetes Service Account (KSA) to a Google Service Account (GSA). The Kf controller runs in the kf namespace and uses a KSA named controller mapped to your GSA to do the following things:

  1. Write metrics to Stackdriver
  2. When a new Kf space is created (kf create-space), the Kf controller creates a new KSA named kf-builder in the new space and maps it to the same GSA.
  3. The kf-builder KSA is used by Tekton to push and pull container images to Google Container Registry (gcr.io)

This diagram illustrates those interactions:

Current limitations

  • Kf doesn't provide pre-built RBAC roles.
    • Until Kf provides this, use RBAC.
  • A developer pushing an app with Kf may also create pods (with kubectl) that can use the kf-builder KSA with the permissions of its associated GSA.
  • Deploying to Kf requires write access to a container registry.
    • Deploy Kf in a dedicated project without access to production resources.
    • Grant developers access to push code to the Artifact Repository by granting them roles/storage.admin on the project, or buckets that Artifact Repository uses.
  • Kf uses the same Pod to fetch, build, and store images.
    • Assume any credentials you provide can be known by the authors and publishers of the buildpacks you use.
  • Kf doesn't support quotas to protect against noisy neighbors.

Other resources

General

Advanced protections