how to add/replace container env in OverridePolicy and keep other envs alive？

[mkloveyy]

This is part of my deployment:

apiVersion: apps/v1
kind: Deployment
spec:
  template:
    spec:
      containers:
      - env:
        - name: CPUS
          value: "1"

This is part of my OverridePolicy:

apiVersion: policy.karmada.io/v1alpha1
kind: OverridePolicy
spec:
  overrideRules:
  - targetCluster:
        clusterNames:
          - sharb-x
      overriders:
        plaintext:
          - path: /spec/template/spec/containers/0/env
            operator: add
            value:
              - name: TEST
                value: captain-test

I wish my cluster sharb-x deployment may be:

apiVersion: apps/v1
kind: Deployment
spec:
  template:
    spec:
      containers:
      - env:
        - name: CPUS
          value: "1"
        - name: TEST
          value: captain-test

But actual is:

apiVersion: apps/v1
kind: Deployment
spec:
  template:
    spec:
      containers:
      - env:
        - name: TEST
          value: captain-test

CPUS env is missing.

So how can I add or replace container env in OverridePolicy and keep other envs alive？
Thanks!

Environment:

• Karmada version: v1.4.1-with-lua
• Kubernetes version: 1.19
• Others:

[RainbowMango]

@chaunceyjiang Could you please help? How can we add an item to a slice?

I'm thinking if we need another overrider dedicated for container env, just like what we did for ImageOverrider .

[XiShanYongYe-Chang]

This is more like a issue of json-patch using, how about testing with the below op:

apiVersion: policy.karmada.io/v1alpha1
kind: OverridePolicy
spec:
  overrideRules:
  - targetCluster:
        clusterNames:
          - sharb-x
      overriders:
        plaintext:
          - path: /spec/template/spec/containers/0/env/0
            operator: add
            value:
              - name: TEST
                value: captain-test

[Poor12]

This is more like a issue of json-patch using, how about testing with the below op:

apiVersion: policy.karmada.io/v1alpha1
kind: OverridePolicy
spec:
  overrideRules:
  - targetCluster:
        clusterNames:
          - sharb-x
      overriders:
        plaintext:
          - path: /spec/template/spec/containers/0/env/0
            operator: add
            value:
              - name: TEST
                value: captain-test

Yes. Another optional overridepolicy is like:

apiVersion: policy.karmada.io/v1alpha1
kind: OverridePolicy
spec:
  overrideRules:
  - targetCluster:
        clusterNames:
          - sharb-x
      overriders:
        plaintext:
          - path: /spec/template/spec/containers/0/env/-
            operator: add
            value:
              - name: TEST
                value: captain-test

[chaunceyjiang]

I'm thinking if we need another overrider dedicated for container env, just like what we did for ImageOverrider .

+1

[chaunceyjiang]

/assign

[RainbowMango]

@chaunceyjiang Can you help add an agenda to the community meeting? Let's gather some feedback there, I'm not sure if this(override envs) is a common case.

@mkloveyy Can you confirm if the suggestion shared by @XiShanYongYe-Chang and @Poor12 works for you?

[mkloveyy]

@RainbowMango Thank for help. I've tried both two suggestions but still didn't work and got same response:

admission webhook xxx denied the request: xxxx Spec: v1.PodSpec.Containers: []v1.Container: v1.Container.Env: []v1.EnvVar: readObjectStart: expect { or n, but found [, error found in #10 byte of ...|],"env":[[{"name":"T|..., bigger context ...|=128","-threadCount=1","-waitSeconds=10"],"env":[[{"name":"TEST","value":"captain-test"}]

And I was wondering if env can be replaced？

[mkloveyy]

@chaunceyjiang Could you please help? How can we add an item to a slice?

I'm thinking if we need another overrider dedicated for container env, just like what we did for ImageOverrider .

Agreed. Maybe an EnvOverrider which can support add/replace/delete env as env operation is a bit complicated.

[chaunceyjiang]

@chaunceyjiang Can you help add an agenda to the community meeting? Let's gather some feedback there

ok.

Agreed. Maybe an EnvOverrider which can support add/replace/delete env as env operation is a bit complicated.

Yes, if users directly use json-patch to modify the env, it is a very complex operation. And it's very easy to make mistakes.

[RainbowMango]

Thank for help. I've tried both two suggestions but still didn't work and got same response:

@XiShanYongYe-Chang @Poor12 Could you please take a look? I'm curious about how complex it is when using plaintext overrider.

[chaunceyjiang]

Thank for help. I've tried both two suggestions but still didn't work and got same response:

      overriders:
        plaintext:
          - path: /spec/template/spec/containers/0/env/0
            operator: add
            value:
              name: TEST
              value: captain-test

You can try this.

[mkloveyy]

Thank for help. I've tried both two suggestions but still didn't work and got same response:

      overriders:
        plaintext:
          - path: /spec/template/spec/containers/0/env/0
            operator: add
            value:
              name: TEST
              value: captain-test

You can try this.

@chaunceyjiang Still not work. I just override all envs temporarily now for use.
@RainbowMango I wonder if can support an EnvOverrider in future as its very useful for users like me. Thx!

[RainbowMango]

I wonder if can support an EnvOverrider in future as its very useful for users like me. Thx!

@mkloveyy we are going to talk about this feature at the community meeting next week, will you present the meeting then? We are glad to hear about your use case there.