Using docker socket in Kubernetes pod

Question

I want to prune docker images, I wrote a small Docker image using node-docker-api and I was able to test it locally with success.
As I've deployed the DaemonSet to Kubernetes, the pod fails to access the Docker socket:

Error: connect EACCES /var/run/docker.sock

The deployment.yaml looks as following:

apiVersion: extensions/v1beta1
kind: DaemonSet
metadata:
  labels:
    name: docker-image-cleanup
  name: docker-image-cleanup
spec:
  template:
    metadata:
      labels:
        app: docker-image-cleanup 
    spec:
      volumes:
        - name: docker-sock
          hostPath:
            path: "/var/run/docker.sock"
            type: File
        - name: docker-directory
          hostPath:
            path: "/var/lib/docker"

      containers:
        - name: docker-image-cleanup
          image: image:tag
          securityContext:
            privileged: true
          env:
            - name: PRUNE_INTERVAL_SECONDS
              value: "30"
            - name: PRUNE_DANGLING
              value: "true"
          volumeMounts:
            - mountPath: /var/run/docker.sock
              name: docker-sock
              readOnly: false
            - mountPath: "/var/lib/docker"
              name: docker-directory
              readOnly: false

Running AKS v1.13.10 - if relevant

Answer 1

I've added runAsUser: 0 to the container properties:

containers:
  - name: docker-image-cleanup
    image: image:tag
    securityContext:
      privileged: true
      runAsUser: 0

Now it works