Kubernetes Secrets Management

Kubernetes Secret objects are designed to store sensitive information such as passwords, tokens, and SSH keys. However, they are base64-encoded, not encrypted by default, and require careful handling to ensure confidentiality, integrity, and availability.

Why Secret Management Matters

Secrets are often a target for attackers. Mismanaged secrets can lead to serious security breaches. Following best practices helps prevent:

• Unauthorized access to confidential data
• Accidental exposure through version control
• Compromise of entire application infrastructure

1. Avoid Committing Secrets to Git.

Bad Example:

apiVersion: v1
kind: Secret
metadata:
  name: db-secret
stringData:
  password: mydbpass123

This might accidentally be pushed to a Git repo.

Best Practice: Use External Secrets or reference secrets from secure vaults, and avoid storing them in the codebase.

2. Use External Secrets Managers.

Integrate Kubernetes with:

• HashiCorp Vault: With Vault Agent injector
• AWS Secrets Manager: Using Secrets Store CSI driver
• Azure Key Vault: With pod identity integration

Use Case: For dynamic secrets that expire, Vault provides short-lived DB credentials that automatically rotate.

3. Enable Encryption at Rest.

By default, secrets are stored unencrypted in etcd. Enable encryption using a Key Management System (KMS):

apiVersion: apiserver.config.k8s.io/v1
kind: EncryptionConfiguration
resources:
  - resources:
      - secrets
    providers:
      - kms:
          name: myKMS
          endpoint: unix:///tmp/socketfile

Ensure your cloud provider’s KMS is enabled (e.g., AWS KMS, Azure Key Vault).

4. Use RBAC to Control Access.

Limit which users and service accounts can access secrets:

kind: Role
apiVersion: rbac.authorization.k8s.io/v1
metadata:
  name: secret-reader
rules:
- apiGroups: [""]
  resources: ["secrets"]
  verbs: ["get"]

5. Avoid Using Environment Variables for Secrets.

Why: Environment variables are exposed in process listings and logs.

Better Approach: Mount secrets as volumes:

volumes:
- name: secret-volume
  secret:
    secretName: db-secret

6. Automate Secret Rotation.

Use tools like Vault, cert-manager, or AWS Secrets Manager to:

• Rotate API keys and DB credentials
• Trigger Kubernetes updates via sidecar injectors or controllers

Example: Vault auto-renews tokens and notifies your app through volume mounts or shared paths.

7. Audit Secret Access.

• Enable Kubernetes Audit Logs
• Use opa-gatekeeper or Kyverno to enforce policies
• Monitor who accesses and modifies secrets

8. Use Namespace Isolation.

Keep secrets scoped to namespaces, and limit cross-namespace access using RoleBinding or NetworkPolicies.

Summary Checklist

By following these best practices, you ensure secrets in Kubernetes are managed securely, minimizing risk and aligning with zero-trust and compliance standards.