How to Decode a Kubernetes Secret

Kubernetes secrets are a way to store sensitive information like passwords, OAuth tokens, and SSH keys. They are encoded in base64 format for safe transmission and storage. In this guide, we'll walk through how to decode these secrets to access the original values.

Prerequisites

You'll need:

• Access to a Kubernetes cluster
• kubectl installed and configured
• Basic command-line skills

Why Are Kubernetes Secrets Encoded?

Kubernetes stores secrets as base64-encoded strings. This is not encryption - it's just a way to safely transmit binary or special characters in YAML. You need to decode these values to read the actual secret data.

Viewing a Secret in Kubernetes

To see the raw data in a secret, use:

kubectl get secret <secret-name> -n <namespace> -o yaml

Replace <secret-name> and <namespace> with your actual secret and namespace. The output will show base64-encoded values under the data: field.

Decoding a Secret Value

Suppose you have a secret named db-credentials in the default namespace. To decode the password field, you can use this command:

kubectl get secret db-credentials -n default -o jsonpath='{.data.password}' | base64 --decode; echo

This command does the following:

• Uses kubectl to extract the base64-encoded value of the password key
• Pipes it to base64 --decode to get the original value
• Adds echo to print a newline for readability

Decoding All Keys in a Secret

If you want to see all key-value pairs in a secret, you can use a loop:

kubectl get secret db-credentials -n default -o json | jq -r '.data | to_entries[] | "\(.key): \(.value | @base64d)"'

Here's what happens:

• The secret is fetched as JSON
• jq iterates over each key in .data, decodes the value, and prints it in key: value format

If you don't have jq, you can install it with brew install jq on macOS or use your package manager on Linux.

Visualizing the Secret Decoding Process

When you decode a secret, the flow looks like this:

+-------------------+
|  base64-encoded   |
|   secret value    |
+-------------------+
          |
          v
+-------------------+
|   base64 decode   |
+-------------------+
          |
          v
+-------------------+
|  original secret  |
+-------------------+

Security Tips

• Never commit decoded secrets to version control.
• Use RBAC to restrict who can view secrets in your cluster.
• Remember that base64 is not encryption - treat secrets as sensitive data at all times.

Next Steps

Explore how to create and update secrets securely, or look into using external secret management tools like HashiCorp Vault or Azure Key Vault for production environments.