Etcd

This guide covers etcd configuration for the control plane of provisioned CAPL clusters.

Default configuration

The quota-backend-bytes for etcd is set to 8589934592 (8 GiB) per recommendation from the etcd documentation.

By default, etcd is configured to be on the same disk as the root filesystem on control plane nodes. If users prefer etcd to be on a separate disk, see the etcd-disk flavor.

ETCD Backups

By default, etcd is not backed-up. To enable backups, users need to choose the etcd-backup-restore flavor.

To begin with, this will deploy a Linode OBJ bucket. This serves as the S3-compatible target to store backups.

Next up, on provisioning the cluster, etcd-backup-restore is deployed as a statefulset. The pod will need the bucket details like the name, region, endpoints and access credentials which are passed using the bucket-details secret that is created when the OBJ bucket gets created.

Enabling SSE

Users can also enable SSE (Server-side encryption) by passing a SSE AES-256 Key as an env var. All env vars here on the pod can be controlled during the provisioning process.

For eg:

export CLUSTER_NAME=test
export OBJ_BUCKET_REGION=us-ord-1
export ETCDBR_IMAGE=docker.io/username/your-custom-image:version
export SSE_KEY=cdQdZ3PrKgm5vmqxeqwQCuAWJ7pPVyHg
clusterctl generate cluster $CLUSTER_NAME \
  --kubernetes-version v1.29.1 \
  --infrastructure linode-linode \
  --flavor etcd-backup-restore \
  | kubectl apply -f -