Kustomize fail to merge .spec.template.spec.containers[].env fields

[shibataka000]

Summary

Kustomize overwrite Rollout's .spec.template.spec.containers[].env fields when overlay. I think kustomize should merge its field instead of overwriting.

Example

Manifests

# kustomization.yaml
apiVersion: kustomize.config.k8s.io/v1beta1
kind: Kustomization
resources:
- rollouts.yaml
patchesStrategicMerge:
- |-
  apiVersion: argoproj.io/v1alpha1
  kind: Rollout
  metadata:
    name: rollouts-demo
  spec:
    template:
      spec:
        containers:
        - name: rollouts-demo
          image: nginx
          env:
          - name: KEY2
            value: VALUE2
openapi:
 path: rollout_cr_schema.json # Same as https://argoproj.github.io/argo-rollouts/features/kustomize/rollout_cr_schema.json

# rollouts.yaml
apiVersion: argoproj.io/v1alpha1
kind: Rollout
metadata:
  name: rollouts-demo
spec:
  strategy:
    blueGreen:
      activeService: rollouts-demo-service
      previewService: rollouts-demo-service-preview
      autoPromotionEnabled: false
  revisionHistoryLimit: 2
  selector:
    matchLabels:
      app: rollouts-demo
  template:
    metadata:
      labels:
        app: rollouts-demo
    spec:
      containers:
      - name: rollouts-demo
        image: argoproj/rollouts-demo:blue
        ports:
        - name: http
          containerPort: 8080
          protocol: TCP
        env:
        - name: KEY1
          value: VALUE1

Expected output of kustomize build command

apiVersion: argoproj.io/v1alpha1
kind: Rollout
metadata:
  name: rollouts-demo
spec:
  revisionHistoryLimit: 2
  selector:
    matchLabels:
      app: rollouts-demo
  strategy:
    blueGreen:
      activeService: rollouts-demo-service
      autoPromotionEnabled: false
      previewService: rollouts-demo-service-preview
  template:
    metadata:
      labels:
        app: rollouts-demo
    spec:
      containers:
      - env:
        - name: KEY1
          value: VALUE1
        - name: KEY2
          value: VALUE2
        image: nginx
        name: rollouts-demo
        ports:
        - containerPort: 8080
          name: http
          protocol: TCP

Actual output of kustomize build command

apiVersion: argoproj.io/v1alpha1
kind: Rollout
metadata:
  name: rollouts-demo
spec:
  revisionHistoryLimit: 2
  selector:
    matchLabels:
      app: rollouts-demo
  strategy:
    blueGreen:
      activeService: rollouts-demo-service
      autoPromotionEnabled: false
      previewService: rollouts-demo-service-preview
  template:
    metadata:
      labels:
        app: rollouts-demo
    spec:
      containers:
      - env:
        - name: KEY2
          value: VALUE2
        image: nginx
        name: rollouts-demo
        ports:
        - containerPort: 8080
          name: http
          protocol: TCP

Note

I guess rollout_cr_schema.json lack following annotation at env properties.

"x-kubernetes-patch-merge-key": "name",
"x-kubernetes-patch-strategy": "merge",

swagger.json, which is referred by gen-crd-spec, has forementioned annotation at env properties at L5873-L5881. But rollout_cr_schema.json lack forementioned annotation at env properties at following lines.

• rollout_cr_schema.json#L173-L268
• rollout_cr_schema.json#L1022-L1117
• rollout_cr_schema.json#L1901-L1996.

Diagnostics

$ kustomize version
{Version:kustomize/v4.4.0 GitCommit:63ec6bdb3d737a7c66901828c5743656c49b60e1 BuildDate:2021-09-27T16:24:12Z GoOs:linux GoArch:amd64}

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[huikang]

Looks like the rollout's kustomize json misses "x-kubernetes-patch-strategy" for all arrays types under the container field, env, ports, volumeDevices

[huikang]

@alexmt , would you mind taking a look at this one? Thanks.

[perenesenko]

This issue could be fixed with #2153

[jessesuen]

This is solved via https://github.com/argoproj/argo-schema-generator.

Read more about the problem/solution here: https://blog.argoproj.io/argo-crds-and-kustomize-the-problem-of-patching-lists-5cfc43da288c