busybox计数器

https://kubernetes.io/docs/concepts/services-networking/dns-pod-service/#dns-policy

apiVersion: v1
kind: Pod
metadata:
  name: counter
spec:
  containers:
  - name: count
    image: busybox
    args: [/bin/sh, -c,
            'i=0; while true; do echo "$i: $(date)"; i=$((i+1)); sleep 1; done']

$ kubectl create -f https://k8s.io/docs/tasks/debug-application-cluster/counter-pod.yaml
pod "counter" created

相当于

docker run -d --name=b1 busybox  i=0; while true; do echo "$i: $(date)"; i=$((i+1)); sleep 1; done

docker logs -f b1

docker run -d \
           --log-driver=fluentd \
           --log-opt fluentd-address=localhost:24224 \
           --log-opt tag="log-test-container-A" \
           busybox sh -c 'while true; do echo "This is a log message from container A"; sleep 10; done;'