Review CRD usage of pointers vs non-pointers

[SaschaSchwarze0]

In our custom resource definitions we are having some fields that are pointers and some are not. My expectation is that:

• optional fields thatuse a pointer
• required fields do not use a pointer

This is done mostly like this, but through Validate nil pointer exceptions during BuildRun Reconcile #396 I noticed that this loc is doing it in a different way:

build/pkg/apis/build/v1alpha1/build_types.go

Line 28 in 87b5d4c

StrategyRef *StrategyRef `json:"strategy"`

And looking around, there is also this loc which does it imo incorrect:

build/pkg/apis/build/v1alpha1/buildrun_types.go

Line 21 in 87b5d4c

BuildRef *BuildRef `json:"buildRef"`

In both cases, a required field is using a reference. My proposal: quickly go through the CRDs and change the pointer usage where it is not correctly done.

For optional strings, one can argue whether one should use a pointer to allow a nil value or assume the empty string means not set. We have both cases in our code. For example:

build/pkg/apis/build/v1alpha1/buildrun_types.go

Line 49 in 87b5d4c

Reason string `json:"reason,omitempty"`

and

build/pkg/apis/build/v1alpha1/buildrun_types.go

Line 53 in 87b5d4c

LatestTaskRunRef *string `json:"latestTaskRunRef,omitempty"`