Generating `x-kubernetes-preserve-unknown-fields: true` with `JsonNode` does not seems to be working

[csviri]

Describe the bug

CRD generator fails when try to generate with

public class ExampleSpec {
  JsonNode someValue;

  @JsonAnyGetter
  JsonNode getSomeValue() {
    return someValue;
  }

  @JsonAnySetter
  void setSomeValue(JsonNode value) {
    this.someValue = value;
  }
}

I get an error message:

Execution default of goal io.fabric8:crd-generator-maven-plugin:7.3.1:generate failed: java.lang.RuntimeException: com.fasterxml.jackson.databind.JsonMappingException: Invalid 'any-getter' annotation on method getSomeValue(): return type is not instance of java.util.Map -> [Help 1]

see reproducer:
operator-framework/java-operator-sdk#2887

If I change it to map it does not generate the
x-kubernetes-preserve-unknown-fields: true attribute.
And in that case also the deserialization does not work.

Is there a workaround for this ATM?
What I want to achieve is to have arbitrary yaml property

Fabric8 Kubernetes Client version

7.3.1

Steps to reproduce

operator-framework/java-operator-sdk#2887

checkout this PR, run mvn clean install

Expected behavior

CRD is generated, CR is properly deserialized

Runtime

Kubernetes (vanilla)

Kubernetes API Server version

1.33

Environment

macOS

Fabric8 Kubernetes Client Logs

Additional context

Thank you!

[shawkins]

I get an error message:

That seems to be a limitation coming from jackson. JsonNode is support for any setter, but not any getter.

Even if you address that, you should still hit https://github.com/FasterXML/jackson-databind/blob/1c1c1b82f6fe6caa90f70accb2a899f053724ede/src/main/java/com/fasterxml/jackson/databind/introspect/BasicBeanDescription.java#L291 with the setter.

If I change it to map it does not generate the x-kubernetes-preserve-unknown-fields: true attribute.

You either need to have implicitPreserveUnknownFields=true, or use the PreserveUnknown annotation.

And in that case also the deserialization does not work.

Do you mean because x-kubernetes-preserve-unknown-fields: true is not set or for some other reason?

[csviri]

Thanks for quick response @shawkins

How it worked is this:

@PreserveUnknownFields private Map<String, Object> someValue;

  public Map<String, Object> getSomeValue() {
    return someValue;
  }

  public void setSomeValue(Map<String, Object> value) {
    this.someValue = value;
  }

but CRD generator generates this from it:

              someValue:
                additionalProperties:
                  type: "object"
                type: "object"
                x-kubernetes-preserve-unknown-fields: true

(if I use this it fails, cannot apply the resource.)

instead of the correct one:

              someValue:
                type: "object"
                x-kubernetes-preserve-unknown-fields: true

[csviri]

we might want to update docs also, here: https://github.com/fabric8io/kubernetes-client/blob/main/doc/CRD-generator.md#generating-x-kubernetes-preserve-unknown-fields-true

[shawkins]

This is what it should look like using a map:

@PreserveUnknownFields 
@JsonIgnore
private Map<String, Object> someValues = new LinkedHashMap<>();

@JsonAnyGetter
public Map<String, Object> getSomeValues() {
    return someValues;
}

@JsonAnySetter
public void setSomeValue(String key, Object value) {
    this.someValues.put(key, value);
}

That's the standard Jackson usage + the PreserveUnknownFields annotation because implicitPreserveUnknownFields defaults to false.

I have not tried using JsonNode or ObjectNode.

we might want to update docs also, here: https://github.com/fabric8io/kubernetes-client/blob/main/doc/CRD-generator.md#generating-x-kubernetes-preserve-unknown-fields-true

Yes, those don't look right.

[csviri]

This:

@PreserveUnknownFields 
@JsonIgnore
private Map<String, Object> someValues = new LinkedHashMap<>();

@JsonAnyGetter
public Map<String, Object> getSomeValues() {
    return someValues;
}

@JsonAnySetter
public void setSomeValue(String key, Object value) {
    this.someValues.put(key, value);
}

generates:

              getSomeValue:
                additionalProperties:
                  type: "object"
                type: "object"

[shawkins]

Ok, a couple of issues:

The jsoningore needs to be on the getter, not the field:

@PreserveUnknownFields 
private Map<String, Object> someValues = new LinkedHashMap<>();

@JsonAnyGetter
@JsonIgnore
public Map<String, Object> getSomeValues() {
    return someValues;
}

@JsonAnySetter
public void setSomeValue(String key, Object value) {
    this.someValues.put(key, value);
}

That matches what we are doing in our generated pojos.

Then the PreserveUnknownFields annotation is effectively useless in this scenario - because the ignoring of the property happens before the marking of preserve unknown. The only test case covering this scenario is incomplete.

That means the only thing that currently works is using implicitPreserveUnknownFields=true with the above.

[csviri]

Hmm, I tried this, but in this case the CRD generator does not generate the property

[shawkins]

Hmm, I tried this, but in this case the CRD generator does not generate the property

You don't want the property in this case correct?

That is the full object schema should be:

---
type: "object"
x-kubernetes-preserve-unknown-fields: true

Not with a someValue field - because the field preservation applies to the parent object, not the field.

[csviri]

What I want to achieve is have a property someValue which can hold an arbitrary yaml value.

according to docs:
https://kubernetes.io/docs/tasks/extend-kubernetes/custom-resources/custom-resource-definitions/#controlling-pruning

it should bedefined like this in CRD:

someValue:
      type: "object"
      x-kubernetes-preserve-unknown-fields: true

[shawkins]

What I want to achieve is have a property someValue which is an arbitrary yaml value.

When you just do:

  JsonNode someValue;

  sonNode getSomeValue() {
    return someValue;
  }

  void setSomeValue(JsonNode value) {
    this.someValue = value;
  }

Without the any getter / setter, you should get:

properties:
  someValue:
    x-kubernetes-preserve-unknown-fields: true
type: "object"

Do you need someValue explicitly typed as object?

Observations:

• https://github.com/fabric8io/kubernetes-client/blob/main/doc/CRD-generator.md#generating-x-kubernetes-preserve-unknown-fields-true should not show the JsonAnyGetter / Setter annotations
• I had a misunderstanding about where PreserverUnknownFields was applicable - it is only on the field level and applies to that field, not the parent. That does make it's usage with any getter / setter less straight-forward because without the implicit handling turned on you have to mark the parent field as preserve unknown.

[csviri]

That, seems to be working, sorry to not being clear on what I wanted, thank you!
Will close the issue.

[shawkins]

I'll see about clarifying the docs and the PreserverUnknownFields annotation.