force_change

deployment1.yaml

apiVersion: apps/v1
kind: Deployment
metadata:
  name: ntp-server
spec:
  template:
    spec:
      containers:
      - name: chrony
        image: "something:0"
        command: ["chronyd", "-d", "-s", "-f", "/config/chronyd.conf"]
        ports:
          - name: ntp
            protocol: UDP
            containerPort: 123
        env:
          - name: SOME_VAR
            value: toto

deployment2.yaml

apiVersion: apps/v1
kind: Deployment
metadata:
  name: app2
spec:
  template:
    spec:
      containers:
      - name: chrony
        image: "something:0"
        command: ["chronyd", "-d", "-s", "-f", "/config/chronyd.conf"]
        ports:
          - name: ntp
            protocol: UDP
            containerPort: 123
        env:
          - name: SOME_VAR
            value: toto

patch.yaml

#@ load("@ytt:overlay", "overlay")

#@overlay/match by=overlay.subset({"kind": "Deployment"}), expects="1+"
---
spec:
  template:
    spec:
      containers:
        #@overlay/match by=overlay.index(0), missing_ok=True
        - env:
          - name: __FORCED_RESTART
            value: rr