Encrypting Secrets at Rest in Kubernetes

1. Introduction

In Kubernetes, managing sensitive information such as passwords, OAuth tokens, and SSH keys is crucial. Secrets are Kubernetes objects designed to store this sensitive data. However, it’s essential to ensure that these secrets are encrypted when stored in the etcd database, which is the default data store for Kubernetes.

2. Key Concepts

• Secrets: Kubernetes objects that store sensitive information.
• etcd: The distributed key-value store used by Kubernetes to store all cluster data.
• Encryption at Rest: The process of encrypting data that is stored on disk.
• Encryption Providers: Components that manage encryption and decryption operations.

3. Encryption Configuration

To enable encryption for Kubernetes secrets, you need to configure the Kubernetes API server with an encryption configuration file. This file specifies the encryption providers and their configurations.

3.1 Example Encryption Configuration

apiVersion: v1
kind: EncryptionConfiguration
resources:
  - resources: ["secrets"]
    providers:
      - identity: {}
      - aesgcm:
          keys:
            - name: key1
              secret: xxxxxxxxxxxxxxxx

4. Step-by-Step Process

Follow these steps to configure encryption for secrets at rest in Kubernetes:

1. Create the encryption configuration file (e.g., encryption-config.yaml).
2. Specify the encryption providers and keys in the configuration file.
3. Update the Kubernetes API server manifest to include the encryption configuration:
    - --encryption-provider-config=/path/to/encryption-config.yaml
4. Restart the Kubernetes API server.

5. Best Practices

• Use strong encryption keys and rotate them regularly.
• Limit access to the encryption configuration file.
• Regularly audit the secrets and their usage.
• Utilize Kubernetes RBAC to restrict access to secrets.

6. FAQ