Log contents of interface objects

[uablrek]

Description

Log contents of interface objects instead of the object itself in structured logging.

After a bit of fumbling I realized the right way is to define a custom MarshalJSON function for the real class. Example:

func (t *Target) MarshalJSON() ([]byte, error) {
	ts := struct {
		Identifier int      `json:"identifier"`
		IPs        []string `json:"ips"`
	}{
		t.getIdentifier(),
		t.nspTarget.GetIps(),
	}
	return json.Marshal(&ts)
}

Issue link

#358

Checklist

• Purpose
  • Bug fix
  • New functionality
  • Documentation
  • Refactoring
  • CI
• Test
  • Unit test
  • E2E Test
  • Tested manually
• Introduce a breaking change
  • Yes (description required)
  • No
• Introduce changes in the Operator
  • Yes (description required)
  • No

[uablrek]

More to come. I will squash commits before "Ready for review". It wasn't nearly as bad as I feared.

[uablrek]

It turns out that this isn't the way after all.

All implementations of an interface that wants to use structured logging should implement the logr.Marshaler interface. It should not be part of the interface itself, but the real implementation types should define a MarshalLog() function. Example (not tested):

func (t *Target) MarshalLog() any {
	ts := struct {
		Identifier int      `json:"identifier"`
		IPs        []string `json:"ips"`
	}{
		t.getIdentifier(),
		t.nspTarget.GetIps(),
	}
	return &ts
}