kubernetes-the-hard-way/docs/06-data-encryption-keys.md

Generating the Data Encryption Config and Key

Kubernetes stores a variety of data including cluster state, application configurations, and secrets. Kubernetes supports the ability to encrypt cluster data at rest, that is, the data stored within etcd.

In this lab you will generate an encryption key and an encryption config suitable for encrypting Kubernetes Secrets.

The Encryption Key

Generate an encryption key. This is simply 32 bytes of random data, which we base64 encode:

ENCRYPTION_KEY=$(head -c 32 /dev/urandom | base64)

The Encryption Config File

Create the encryption-config.yaml encryption config file:

cat > encryption-config.yaml <<EOF
kind: EncryptionConfig
apiVersion: v1
resources:
  - resources:
      - secrets
    providers:
      - aescbc:
          keys:
            - name: key1
              secret: ${ENCRYPTION_KEY}
      - identity: {}
EOF

Copy the encryption-config.yaml encryption config file to each controller instance:

for instance in controlplane01 controlplane02; do
  scp encryption-config.yaml ${instance}:~/
done

Move encryption-config.yaml encryption config file to appropriate directory.

for instance in controlplane01 controlplane02; do
  ssh ${instance} sudo mkdir -p /var/lib/kubernetes/
  ssh ${instance} sudo mv encryption-config.yaml /var/lib/kubernetes/
done

Reference: https://kubernetes.io/docs/tasks/administer-cluster/encrypt-data/#encrypting-your-data

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