Secrets are not encrypted by default in Kubernetes - Commands & Configuration

Introduction

Kubernetes stores Secrets in its database without encryption by default. This means sensitive data like passwords or tokens can be exposed if someone accesses the database directly.

When you want to store sensitive information like API keys or passwords in Kubernetes.

When you need to share credentials securely between your application and Kubernetes.

When you want to avoid exposing secrets in plain text in configuration files.

When you want to understand the risks of default Kubernetes secret storage.

When you plan to enable encryption for better security of your secrets.

Commands

This command creates a secret named 'my-secret' with a password stored as base64 encoded in Kubernetes.

Terminal

kubectl create secret generic my-secret --from-literal=password=supersecret123

Expected Output

secret/my-secret created

→

--from-literal - Creates a secret from a literal value directly in the command line

This command shows the secret data in base64 encoded form, demonstrating that the secret is not encrypted by default in the cluster.

Terminal

kubectl get secret my-secret -o yaml

Expected Output

apiVersion: v1

kind: Secret

metadata:

  name: my-secret

data:

  password: c3VwZXJzZWNyZXQxMjM=

type: Opaque

→

-o yaml - Outputs the secret in YAML format to see the stored data

Key Concept

If you remember nothing else from this pattern, remember: Kubernetes stores secrets base64 encoded but not encrypted by default, so extra steps are needed to protect sensitive data.

Common Mistakes

Assuming Kubernetes encrypts secrets automatically

Secrets are only base64 encoded, which is not encryption and can be easily decoded.

Enable encryption at rest in Kubernetes or use external secret management tools.

Storing secrets in plain text files or environment variables without encryption

This exposes sensitive data to anyone with access to those files or environment.

Use Kubernetes Secrets and enable encryption or external vaults to secure sensitive data.

Summary

Create a secret using kubectl with sensitive data stored base64 encoded.

View the secret in YAML format to see that data is not encrypted by default.

Understand that base64 encoding is not secure encryption and additional protection is needed.

Practice

1. What is the default way Kubernetes stores Secrets?

easy

A. Hashed using SHA-256 before storage

B. As base64 encoded plain text in etcd

C. Stored in an external vault automatically

D. Encrypted with AES-256 by default

Solution

1. Step 1: Understand Kubernetes default Secret storage

   Kubernetes stores Secrets in etcd as base64 encoded strings, which is not encryption but simple encoding.

2. Step 2: Confirm encryption is not enabled by default

   Encryption at rest must be explicitly configured; by default, Secrets are not encrypted.

3. Final Answer:

   As base64 encoded plain text in etcd -> Option B

4. Quick Check:

   Default Secret storage = base64 plain text [OK]

Hint: Remember: base64 is encoding, not encryption [OK]

Common Mistakes:

• Confusing base64 encoding with encryption
• Assuming Secrets are encrypted by default
• Thinking Kubernetes uses external vault automatically

2. Which of the following is the correct way to enable encryption of Secrets in Kubernetes?

easy

A. Configure EncryptionConfiguration file in API server flags

B. Set encryption: true in the Secret manifest

C. Add --encryption-provider flag to kubelet

D. Use kubectl encrypt secret command

Solution

1. Step 1: Identify where encryption is configured

   Encryption at rest is enabled by configuring the API server with an EncryptionConfiguration file and passing it via flags.

2. Step 2: Verify other options are invalid

   Kubelet does not handle encryption, Secret manifests do not have encryption fields, and kubectl has no encrypt command.

3. Final Answer:

   Configure EncryptionConfiguration file in API server flags -> Option A

4. Quick Check:

   Encryption enabled via API server config [OK]

Hint: Encryption config is on API server, not kubelet or kubectl [OK]

Common Mistakes:

• Trying to encrypt Secrets via kubectl commands
• Assuming kubelet manages encryption
• Adding encryption fields in Secret YAML

3. Given this snippet from an EncryptionConfiguration file:

{
  "kind": "EncryptionConfiguration",
  "apiVersion": "apiserver.config.k8s.io/v1",
  "resources": [
    {
      "resources": ["secrets"],
      "providers": [
        {"aescbc": {"keys": [{"name": "key1", "secret": "c2VjcmV0MTIzNDU2Nzg5MDEyMzQ1Njc4OTA="}]}},
        {"identity": {}}
      ]
    }
  ]
}

What does this configuration do?

medium

A. Encrypts Secrets using AES-CBC with key1, falling back to no encryption

B. Encrypts all resources except Secrets

C. Disables encryption for Secrets

D. Encrypts Secrets using identity provider only

Solution

1. Step 1: Analyze the providers list for Secrets

   The providers list has an AES-CBC encryption provider with a key named key1, followed by identity (no encryption) as fallback.

2. Step 2: Understand the effect on Secrets

   This means Secrets are encrypted with AES-CBC using key1; if decryption fails, identity provider returns plain data.

3. Final Answer:

   Encrypts Secrets using AES-CBC with key1, falling back to no encryption -> Option A

4. Quick Check:

   Encryption config with AES-CBC + identity fallback [OK]

Hint: First provider encrypts, second is fallback identity [OK]

Common Mistakes:

• Thinking identity means encryption is disabled
• Assuming all resources are encrypted, not just Secrets
• Confusing provider order effect

4. You configured encryption for Secrets but still see base64 encoded plain text in etcd. What is the most likely cause?

medium

A. Secrets manifest missing encryption annotation

B. Encryption key is too short

C. kubectl version is outdated

D. API server was not restarted after adding EncryptionConfiguration

Solution

1. Step 1: Check if API server reload is needed

   EncryptionConfiguration changes require API server restart to take effect.

2. Step 2: Verify other options are irrelevant

   Secrets do not need annotations for encryption, kubectl version does not affect encryption, and key length would cause errors, not silent failure.

3. Final Answer:

   API server was not restarted after adding EncryptionConfiguration -> Option D

4. Quick Check:

   API server restart required for encryption config [OK]

Hint: Restart API server after config changes [OK]

Common Mistakes:

• Forgetting to restart API server
• Adding encryption annotations to Secrets
• Blaming kubectl version for encryption issues

5. You want to ensure all Secrets in your cluster are encrypted at rest. Which steps should you follow? Select the correct sequence.

hard

A. Enable encryption in kube-proxy config, restart kube-proxy, check logs

B. Add encryption field to Secret manifests, restart kubelet, verify kubectl output

C. Create EncryptionConfiguration file, update API server flags, restart API server, verify etcd data

D. Run kubectl encrypt secrets, update RBAC, restart API server

Solution

1. Step 1: Prepare EncryptionConfiguration file

   Create a file defining encryption providers for Secrets, typically AES-CBC or AES-GCM.

2. Step 2: Update API server flags and restart

   Pass the EncryptionConfiguration file path to the API server via flags and restart it to apply changes.

3. Step 3: Verify Secrets are encrypted in etcd

   Check etcd data to confirm Secrets are stored encrypted, not just base64 encoded.

4. Final Answer:

   Create EncryptionConfiguration file, update API server flags, restart API server, verify etcd data -> Option C

5. Quick Check:

   Encryption setup = config file + API server restart + verify [OK]

Hint: Encryption needs config file + API server restart + verify [OK]

Common Mistakes:

• Trying to encrypt Secrets via manifest changes
• Restarting wrong components like kubelet or kube-proxy
• Using non-existent kubectl encrypt command