verify dind (docker in docker) working on each node of a kubernetes cluster

README.md

Check the logs of the docker container in each pod of the deploy to verify dind is working on your kubernetes cluster. Pods will restart if they cannot talk to docker server.

dind-test-ds.yaml

apiVersion: apps/v1
kind: DaemonSet
metadata:
  name: dind-test
  labels:
    run: dind-test
spec:
  selector:
    matchLabels:
      run: dind-test
  template:
    metadata:
      labels:
        run: dind-test
    spec:
      containers:
      # docker ≥19 serves a tls server by default on port 2376, ≤18 serves unencrypted on 2375
      - image: docker:18-dind
        name: dind
        securityContext:
          privileged: true
      - image: docker:stable
        name: docker
        command: [/bin/sh]
        args:
        - -c
        - |
            set -x;
            fails=0;
            while true; do
              sleep 10 && date;
              if ! docker version; then fails=$((fails+1)); fi;
              if [[ $fails -ge 3 ]]; then exit 1; fi;
            done
        env:
        - name: DOCKER_HOST
          value: tcp://localhost:2375