hostPath Volumes

A hostPath volume mounts a specific directory from the node straight into a Pod.

Sometimes you want a Pod to use an exact folder that already exists on the node, such as a mounted USB drive or a config directory. A hostPath volume does this directly, without a PVC or provisioner.

Use with care

  • The Pod is pinned to whichever node holds that path.
  • It bypasses Kubernetes storage management, so it is less portable.
  • It can be a security risk if the path exposes sensitive host files.

hostPath is common on edge devices where you know the hardware, but avoid it for portable production apps.

Example

Example · yaml
apiVersion: v1
kind: Pod
metadata:
  name: logger
spec:
  containers:
    - name: app
      image: busybox
      command: ["sh", "-c", "echo hi >> /data/log.txt; sleep 3600"]
      volumeMounts:
        - name: host-data
          mountPath: /data
  volumes:
    - name: host-data
      hostPath:
        path: /opt/app-data
        type: DirectoryOrCreate

When to use it

  • A developer mounts the Docker socket from the host into a CI runner pod so the pod can build container images using the node's Docker daemon.
  • An operator mounts /etc/ssl/certs from a node into a pod to share the host's certificate bundle without baking certs into the image.
  • A log aggregator pod mounts /var/log from the host to collect and forward system logs without requiring a dedicated log daemon on the node.

More examples

Mount a host directory into a Pod

Mounts the node's /var/log directory into the container so it can read host-level log files directly.

Example · yaml
volumes:
- name: host-logs
  hostPath:
    path: /var/log
    type: Directory
containers:
- name: log-reader
  image: busybox
  command: ['sh', '-c', 'tail -f /host/syslog']
  volumeMounts:
  - name: host-logs
    mountPath: /host

Use hostPath for Docker socket

Exposes the node's Docker socket inside the container, enabling Docker-in-Docker builds from a pod.

Example · yaml
volumes:
- name: docker-sock
  hostPath:
    path: /var/run/docker.sock
    type: Socket
containers:
- name: builder
  image: docker:dind
  volumeMounts:
  - name: docker-sock
    mountPath: /var/run/docker.sock

Create a hostPath volume with type check

Uses DirectoryOrCreate so k3s creates the host directory automatically if it is missing when the pod starts.

Example · yaml
volumes:
- name: config-dir
  hostPath:
    path: /etc/app-config
    type: DirectoryOrCreate
# type: DirectoryOrCreate creates the dir if it does not exist

Related

k3s pvck3s local path

Discussion

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