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.
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.
In addition to the Current limitations described below, it is important that you read through and understand the items outlined in this section.
By default, Kf uses Workload Identity to provide secure delivery and rotation of the Service Account credentials used by Kf to interact with your Google 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:
- Write metrics to Stackdriver
- When a new Kf space is created (
kf create-space), the Kf controller creates a new KSA named
kf-builderin the new space and maps it to the same GSA.
kf-builderKSA is used by Tekton to push and pull container images to Google Container Registry (gcr.io)
This diagram illustrates those interactions:
In order to mimic Cloud Foundry’s UID/GID mapping, containers in Kf that mount NFS volumes need
the ability to run as
root and the ability to access the FUSE device of the kernel running the
A developer pushing an app with Kf can also create Pods (with
kubectl) that can use the
kf-builderKSA with the permissions of its associated GSA.
Kf uses the same Pod to fetch, build, and store images. Assume that any credentials that 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. Use Kubernetes resource quotas.