How to check if a field was explicitly set in a custom resource

Question

Update: I found that my code actually working. The reason that reconcile loop get false at first is because I have another operator existing in my cluster and doing boolean flipping automatically. After deleted that operator, my code works as expected.

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This question is related with Kubernetes and Operator-SDK. Let's say I have a Custom Resource which spec is shows as following:

apiVersion: my.example.com/v1alpha1
kind: MyStore
metadata:
  name: mystore
spec:
  name: "sample-store"
  address: "sample-address"
  zip: "sample-zip"
  open: true

Where the last field open is boolean type used to indicate whether the store is open or not. In reconcile loop of my operator, I would like to know whether a CR of MyStore kind was explicitly set value of open field. For example:

1. If the value CR's open field has been explicitly set as true or false, then reconcile loop should take this value directly.
2. If the CR does not have open field explicitly set, or this field is not existing, reconcile loop should consider the default value of open as true.

Currently I tried this way, which is set the type of open field as pointer of boolean in my struct:

type MyStoreSpec struct {
    Name         string   `json:"name"`
    Address      string   `json:"address"`
    Zip          string   `json:"zip"`
    Open         *bool    `json:"open"` // Here I use *bool as type
}


type MyStore stuct {
    metav1.TypeMeta   `json:",inline"`
    metav1.ObjectMeta `json:"metadata,omitempty"`

    Spec   MyStoreSpec   `json:"spec,omitempty"`
}

Then in reconcile loop I check the existing of open field like this:

store := &examplev1beta1.MyStore{}
r.client.Get(context.TODO(), request.NamespacedName, store)
if store.Spec.Open == nil {
    a := true
    store.Spec.Open = &a
}

The idea of above code is to check whether the pointer of open field exists: if pointer is null, set true to open field. And the idea is from this question Go: How to check if a struct property was explicitly set to a zero value?

But above code is not working as I expected: if open field of a CR is not exists (not have value be explicitly set), the value of store.Spec.Open will be parsed as false but not nil.

Is there any other ways to do the field value checking?

Answer 1

Try adding omitempty with your json tag.

type MyStoreSpec struct {
    Name         string   `json:"name"`
    Address      string   `json:"address"`
    Zip          string   `json:"zip"`
    Open         *bool    `json:"open,omitempty"` // Here I use *bool as type
}

Rest of the code should work.