How To Write A Secrets Stanza

5 min read Oct 06, 2024

Secrets are essential for securely storing sensitive information in your Kubernetes deployments. They allow you to manage passwords, API keys, and other confidential data without exposing them directly in your configuration files. The secrets stanza plays a crucial role in defining how these secrets are managed and accessed within your Kubernetes cluster.

Understanding the Secrets Stanza

The secrets stanza is a key component of your Kubernetes configuration file, typically a YAML file. It specifies how Kubernetes should handle secrets for your applications. Let's break down the structure of a secrets stanza:

apiVersion: v1
kind: Secret
metadata:
  name: my-secret
  namespace: default
type: Opaque
data:
  username: "YOUR_USERNAME"
  password: "YOUR_PASSWORD"

Essential Components

apiVersion: This defines the version of the Kubernetes API being used.
kind: Specifies that this is a Secret object.
metadata:
- name: The name of the secret. This is how you will reference it in your deployments.
- namespace: The namespace where the secret will be stored.
type: The type of secret. Common types include:
- Opaque: For general secrets, where the data is treated as raw bytes.
- kubernetes.io/service-account-token: Used for service account tokens, granting access to Kubernetes resources.
data: A map of key-value pairs. This is where you store your sensitive data. Note: Data is usually base64 encoded.

Writing a Secrets Stanza: Step-by-Step

Determine the type of secret: Decide whether you need a simple Opaque secret for storing credentials or a specific type like kubernetes.io/service-account-token for accessing Kubernetes resources.
Choose a descriptive name: Give your secret a name that clearly identifies its purpose.
Specify the namespace: Indicate the namespace where the secret should be created.
Encode your data: If you are storing plain text credentials, you'll need to encode them using Base64 encoding. This ensures the data is not stored in plain text within Kubernetes.
Create the YAML file: Write the secrets stanza into a YAML file, carefully formatting it to ensure correctness.

Example

Let's create a secrets stanza for storing database credentials:

apiVersion: v1
kind: Secret
metadata:
  name: database-creds
  namespace: my-app
type: Opaque
data:
  db_user: "YWRtaW4="  # "admin" base64 encoded
  db_password: "cGFzc3dvcmQ=" # "password" base64 encoded

Accessing Secrets

Once you've created a secret, you can access it in your applications using Kubernetes environment variables. For example, to access the database credentials from the example above:

containers:
  - name: my-app
    image: my-app-image
    env:
      - name: DB_USER
        valueFrom:
          secretKeyRef:
            name: database-creds
            key: db_user
      - name: DB_PASSWORD
        valueFrom:
          secretKeyRef:
            name: database-creds
            key: db_password

Best Practices

Minimize Scope: Limit the access permissions of your secrets to the necessary applications and users.
Secret Rotation: Regularly rotate secrets to enhance security.
Use Dedicated Secret Management Tools: Consider tools like Vault or HashiCorp Vault for more advanced secret management.

Conclusion

The secrets stanza in your Kubernetes configuration is essential for securely managing and accessing sensitive information within your deployments. By following these steps and best practices, you can ensure that your secrets are stored and accessed securely, enhancing the security and reliability of your applications.