Add ptr package (#443)

This has a helper utility wrapper for pointers. We want this to help make it a bit cleaner when dealing with pointers and trying to prevent nil pointer dereferences.

Author: joekr

cloud/ociutil/ptr/from_ptr.go

@@ -0,0 +1,40 @@
+package ptr
+
+import infrastructurev1beta2 "github.com/oracle/cluster-api-provider-oci/api/v1beta2"
+
+// ToString returns string value dereferenced if the passed
+// in pointer was not nil. Returns a string zero value if the
+// pointer was nil.
+func ToString(p *string) (v string) {
+	if p == nil {
+		return v
+	}
+
+	return *p
+}
+
+// ToStringSlice returns a slice of string values, that are
+// dereferenced if the passed in pointer was not nil. Returns a string
+// zero value if the pointer was nil.
+func ToStringSlice(vs []*string) []string {
+	ps := make([]string, len(vs))
+	for i, v := range vs {
+		ps[i] = ToString(v)
+	}
+
+	return ps
+}
+
+// ToNSGSlice returns a slice of NSG values, that are
+// dereferenced if the passed in pointer was not nil. Returns an empty slice
+// zero value if the pointer was nil.
+func ToNSGSlice(vs []*infrastructurev1beta2.NSG) []infrastructurev1beta2.NSG {
+	ps := make([]infrastructurev1beta2.NSG, len(vs))
+	for i, v := range vs {
+		if v != nil {
+			ps[i] = *v
+		}
+	}
+
+	return ps
+}

cloud/ociutil/ptr/from_ptr_test.go

@@ -0,0 +1,118 @@
+package ptr
+
+import (
+	"testing"
+
+	infrastructurev1beta2 "github.com/oracle/cluster-api-provider-oci/api/v1beta2"
+)
+
+func TestToString(t *testing.T) {
+	tests := []struct {
+		name  string
+		input *string
+		want  string
+	}{
+		{
+			name:  "nil pointer",
+			input: nil,
+			want:  "",
+		},
+		{
+			name:  "non-nil pointer",
+			input: func() *string { s := "test"; return &s }(),
+			want:  "test",
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			if got := ToString(tt.input); got != tt.want {
+				t.Errorf("ToString() = %v, want %v", got, tt.want)
+			}
+		})
+	}
+}
+
+func TestToStringSlice(t *testing.T) {
+	tests := []struct {
+		name  string
+		input []*string
+		want  []string
+	}{
+		{
+			name:  "nil slice",
+			input: nil,
+			want:  []string{},
+		},
+		{
+			name:  "empty slice",
+			input: []*string{},
+			want:  []string{},
+		},
+		{
+			name:  "slice with nil elements",
+			input: []*string{nil, nil},
+			want:  []string{"", ""},
+		},
+		{
+			name:  "slice with non-nil elements",
+			input: []*string{func() *string { s := "test1"; return &s }(), func() *string { s := "test2"; return &s }()},
+			want:  []string{"test1", "test2"},
+		},
+		{
+			name:  "slice with mixed nil and non-nil elements",
+			input: []*string{nil, func() *string { s := "test"; return &s }(), nil},
+			want:  []string{"", "test", ""},
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			if got := ToStringSlice(tt.input); len(got) != len(tt.want) || (len(got) > 0 && got[0] != tt.want[0]) {
+				t.Errorf("ToStringSlice() = %v, want %v", got, tt.want)
+			}
+		})
+	}
+}
+
+func TestToNSGSlice(t *testing.T) {
+	tests := []struct {
+		name  string
+		input []*infrastructurev1beta2.NSG
+		want  []infrastructurev1beta2.NSG
+	}{
+		{
+			name:  "nil slice",
+			input: nil,
+			want:  []infrastructurev1beta2.NSG{},
+		},
+		{
+			name:  "empty slice",
+			input: []*infrastructurev1beta2.NSG{},
+			want:  []infrastructurev1beta2.NSG{},
+		},
+		{
+			name:  "slice with nil elements",
+			input: []*infrastructurev1beta2.NSG{nil, nil},
+			want:  []infrastructurev1beta2.NSG{{}, {}},
+		},
+		{
+			name:  "slice with non-nil elements",
+			input: []*infrastructurev1beta2.NSG{&infrastructurev1beta2.NSG{}, &infrastructurev1beta2.NSG{}},
+			want:  []infrastructurev1beta2.NSG{{}, {}},
+		},
+		{
+			name:  "slice with mixed nil and non-nil elements",
+			input: []*infrastructurev1beta2.NSG{nil, &infrastructurev1beta2.NSG{}, nil},
+			want:  []infrastructurev1beta2.NSG{{}, {}, {}},
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			if got := ToNSGSlice(tt.input); len(got) != len(tt.want) {
+				t.Errorf("ToNSGSlice() length = %v, want %v", len(got), len(tt.want))
+			}
+		})
+	}
+}

cloud/scope/load_balancer_reconciler.go

@@ -22,6 +22,7 @@ import (
 
 	infrastructurev1beta2 "github.com/oracle/cluster-api-provider-oci/api/v1beta2"
 	"github.com/oracle/cluster-api-provider-oci/cloud/ociutil"
+	"github.com/oracle/cluster-api-provider-oci/cloud/ociutil/ptr"
 	"github.com/oracle/oci-go-sdk/v65/common"
 	"github.com/oracle/oci-go-sdk/v65/loadbalancer"
 	"github.com/pkg/errors"
@@ -183,8 +184,8 @@ func (s *ClusterScope) CreateLB(ctx context.Context, lb infrastructurev1beta2.Lo
 		DefinedTags:  s.GetDefinedTags(),
 	}
 	nsgs := make([]string, 0)
-	for _, nsg := range s.OCIClusterAccessor.GetNetworkSpec().Vcn.NetworkSecurityGroup.List {
-		if nsg != nil && nsg.Role == infrastructurev1beta2.ControlPlaneEndpointRole {
+	for _, nsg := range ptr.ToNSGSlice(s.OCIClusterAccessor.GetNetworkSpec().Vcn.NetworkSecurityGroup.List) {
+		if nsg.Role == infrastructurev1beta2.ControlPlaneEndpointRole {
 			if nsg.ID != nil {
 				nsgs = append(nsgs, *nsg.ID)
 			}