The following are some notes I made while watching Lukonde Mwila’s informative talk on Container Security in AWS Container Services, which was part of Containers from the Couch Container Day.
Cluster Weaknesses & Vulnerabilities
Security considerations at each layer of the K8S stack:
|Workload||Tends to be top of mind when people think about securing Kubernetes but it’s important to consider layers that are lower down in the stack as well.|
|Infrastructure / Hosts||
Considerations for securing K8S
- Kubernetes can’t currently keep track of identities so you need to manage that outside of the system and then map that to the context of Kubernetes
- ABAC = Attribute Based Access Control
- PSP = Pod Security Policies (these are being deprecated)
Image Scanning & Policy Enforcement
Scanning only provides point-in-time assurance that a container image is “good”. Therefore need to think about scanning at multiple stages in the image lifecycle, not just at creation. Key stages are:
- Container image scanning at CI pipeline stage
- Tools for this include NeuVector and Trivy
- Registry scanning of images
- Policy enforcement in pipelines
- Tools for this include Kyverno / Datree
- Secrets in Kubernetes are natively insecure. They aren’t encrypted at rest, only base64 encoded!
- Bitnami Sealed Secrets solves this issue by providing a mechanism to encrypt the secret data and make it safe to store in Git repositories.
kubeseal(a CLI tool) to transform Custom Resource Definition (CRD) secrets into sealed secrets.
- A Sealed Secrets controller that’s used to generate the encryption key, and decrypt sealed secrets into secrets that can be used by pods.
External Secrets Operator (ESO)
- A Kubernetes operator that enables integration with an external secrets management system (e.g. HashiCorp Vault, AWS SSM).
- SecretStore - This is a namespaced resource that determines how an external secret will be accessed from an authentication perspective.
- ExternalSecret - This is a resource that declares what data you want to fetch from the external secrets manager.