etcd-defrag

packaged by Chainguard

Chainguard Container for etcd-defrag

An easier to use and smarter etcd defragmentation tool

Chainguard Containers are regularly-updated, secure-by-default container images.

Download this Container Image

For those with access, this container image is available on cgr.dev:

docker pull cgr.dev/ORGANIZATION/etcd-defrag:latest

Be sure to replace the ORGANIZATION placeholder with the name used for your organization's private repository within the Chainguard Registry.

Compatibility Notes

The Chainguard etcd-defrag image is designed to be a drop-in replacement for the upstream ghcr.io/ahrtr/etcd-defrag image. Like the upstream image, the entrypoint is /ko-app/etcd-defrag, which points to the binary installed at /usr/bin/etcd-defrag. The image runs as the nonroot user (UID 65532) by default and does not include a shell or package manager.

etcd-defrag is a Go command-line tool, licensed under the MIT License, that defragments etcd members one at a time. It is easier to use and smarter than etcdctl defrag.

Getting Started

Display the available flags:

docker run --rm cgr.dev/ORGANIZATION/etcd-defrag:latest -h

Defragment every member of a cluster, starting from a single endpoint:

docker run --rm cgr.dev/ORGANIZATION/etcd-defrag:latest \
  --endpoints http://etcd-0.etcd:2379 \
  --cluster

For TLS-secured clusters, mount the certificates and pass --cacert, --cert, and --key. Mounted files must be readable by UID 65532.

etcd-defrag is commonly run as a Kubernetes CronJob on the control plane. The following manifest is based on the upstream CronJob example for kubeadm clusters. It schedules the job on a control-plane node, uses the host network to reach etcd at 127.0.0.1:2379, and mounts the etcd certificates from /etc/kubernetes/pki/etcd:

cat > etcd-defrag-cronjob.yaml <<EOF
apiVersion: batch/v1
kind: CronJob
metadata:
  name: etcd-defrag
  namespace: kube-system
spec:
  schedule: "14 9 * * 1-5"
  jobTemplate:
    spec:
      template:
        spec:
          containers:
          - name: etcd-defrag
            image: cgr.dev/ORGANIZATION/etcd-defrag:latest
            args:
            - --endpoints=https://127.0.0.1:2379
            - --cacert=/etc/kubernetes/pki/etcd/ca.crt
            - --cert=/etc/kubernetes/pki/etcd/healthcheck-client.crt
            - --key=/etc/kubernetes/pki/etcd/healthcheck-client.key
            - --cluster
            - --defrag-rule
            - "dbQuotaUsage > 0.8 || dbSize - dbSizeInUse > 200*1024*1024"
            volumeMounts:
            - mountPath: /etc/kubernetes/pki/etcd
              name: etcd-certs
              readOnly: true
          volumes:
          - name: etcd-certs
            hostPath:
              path: /etc/kubernetes/pki/etcd
              type: Directory
          restartPolicy: OnFailure
          hostNetwork: true
          securityContext:
            runAsUser: 0
          tolerations:
          - effect: NoSchedule
            key: node-role.kubernetes.io/control-plane
          - effect: NoExecute
            operator: Exists
          affinity:
            nodeAffinity:
              requiredDuringSchedulingIgnoredDuringExecution:
                nodeSelectorTerms:
                - matchExpressions:
                  - key: node-role.kubernetes.io/control-plane
                    operator: Exists
EOF
kubectl apply -f etcd-defrag-cronjob.yaml

kubeadm creates the etcd client keys readable only by root, so this example sets runAsUser: 0, as the upstream example does. To run the job as the image's default nonroot user, make the certificate and key files readable by UID 65532 and remove the securityContext override.

Be sure to replace the ORGANIZATION placeholder with the name used for your organization's private repository within the Chainguard Registry.

Configuration

Every command-line flag can also be set through an environment variable with the ETCD_DEFRAG_ prefix, for example ETCD_DEFRAG_ENDPOINTS or ETCD_DEFRAG_DIAL_TIMEOUT. Refer to the upstream documentation for the full list of options, including defragmentation rules (--defrag-rule), compaction, and leader movement.

What are Chainguard Containers?

Chainguard's free tier of Starter container images are built with Wolfi, our minimal Linux undistro.

All other Chainguard Containers are built with Chainguard OS, Chainguard's minimal Linux operating system designed to produce container images that meet the requirements of a more secure software supply chain.

The main features of Chainguard Containers include:

• Minimal design, without unnecessary software bloat
• Daily builds to ensure container images are up-to-date with available security patches
• High quality build-time SBOMs attesting to the provenance of all artifacts within the image
• Verifiable signatures provided by Sigstore
• Reproducible builds with Cosign and apko (read more about reproducibility)

For cases where you need container images with shells and package managers to build or debug, most Chainguard Containers come paired with a development, or -dev, variant.

In all other cases, including Chainguard Containers tagged as :latest or with a specific version number, the container images include only an open-source application and its runtime dependencies. These minimal container images typically do not contain a shell or package manager.

Although the -dev container image variants have similar security features as their more minimal versions, they include additional software that is typically not necessary in production environments. We recommend using multi-stage builds to copy artifacts from the -dev variant into a more minimal production image.

Need additional packages?

To improve security, Chainguard Containers include only essential dependencies. Need more packages? Chainguard customers can use Custom Assembly to add packages, either through the Console, chainctl, or API.

To use Custom Assembly in the Chainguard Console: navigate to the image you'd like to customize in your Organization's list of images, and click on the Customize image button at the top of the page.

Learn More

Refer to our Chainguard Containers documentation on Chainguard Academy. Chainguard also offers VMs and Libraries — contact us for access.

Trademarks

This software listing is packaged by Chainguard. The trademarks set forth in this offering are owned by their respective companies, and use of them does not imply any affiliation, sponsorship, or endorsement by such companies.