apiVersion: apps/v1
kind: Deployment
metadata:
  name: web
spec:
  selector:
    matchLabels:
      app: web
  replicas: 1
  template:
    metadata:
      labels:
        app: web
    spec:
      initContainers:
      - name: wait-config-server
        image: busybox
        command: ["sh", "-c", "for i in $(seq 1 300); do nc -zvw1 config-server 8080 && exit 0 || sleep 3; done; exit 1"]
      containers:
      - name: web
        image: my-mage
        ports:
        - containerPort: 80
          ...