Add feature gates infrastructure (#90)

cmd/manager/main.go

@@ -35,7 +35,10 @@ import (
 	"github.com/operator-framework/catalogd/internal/source"
 	"github.com/operator-framework/catalogd/internal/version"
 	corecontrollers "github.com/operator-framework/catalogd/pkg/controllers/core"
+	"github.com/operator-framework/catalogd/pkg/features"
 	"github.com/operator-framework/catalogd/pkg/profile"
+	"github.com/spf13/pflag"
+
 	//+kubebuilder:scaffold:imports
 	"github.com/operator-framework/catalogd/api/core/v1alpha1"
 )
@@ -70,13 +73,17 @@ func main() {
 	// TODO: should we move the unpacker to some common place? Or... hear me out... should catalogd just be a rukpak provisioner?
 	flag.StringVar(&unpackImage, "unpack-image", "quay.io/operator-framework/rukpak:v0.12.0", "The unpack image to use when unpacking catalog images")
 	flag.StringVar(&sysNs, "system-ns", "catalogd-system", "The namespace catalogd uses for internal state, configuration, and workloads")
+	flag.BoolVar(&profiling, "profiling", false, "enable profiling endpoints to allow for using pprof")
+	flag.BoolVar(&catalogdVersion, "version", false, "print the catalogd version and exit")
 	opts := zap.Options{
 		Development: true,
 	}
-	flag.BoolVar(&profiling, "profiling", false, "enable profiling endpoints to allow for using pprof")
-	flag.BoolVar(&catalogdVersion, "version", false, "print the catalogd version and exit")
 	opts.BindFlags(flag.CommandLine)
-	flag.Parse()
+
+	// Combine both flagsets and parse them
+	pflag.CommandLine.AddGoFlagSet(flag.CommandLine)
+	features.CatalogdFeatureGate.AddFlag(pflag.CommandLine)
+	pflag.Parse()
 
 	if catalogdVersion {
 		fmt.Printf("%#v\n", version.Version())

go.mod

@@ -8,9 +8,11 @@ require (
 	github.com/onsi/ginkgo/v2 v2.9.7
 	github.com/onsi/gomega v1.27.7
 	github.com/operator-framework/operator-registry v1.26.3
+	github.com/spf13/pflag v1.0.5
 	k8s.io/api v0.26.0
 	k8s.io/apimachinery v0.26.0
 	k8s.io/client-go v0.26.0
+	k8s.io/component-base v0.26.0
 	k8s.io/utils v0.0.0-20221128185143-99ec85e7a448
 	sigs.k8s.io/controller-runtime v0.14.0
 )
@@ -57,7 +59,6 @@ require (
 	github.com/prometheus/client_model v0.3.0 // indirect
 	github.com/prometheus/common v0.37.0 // indirect
 	github.com/prometheus/procfs v0.8.0 // indirect
-	github.com/spf13/pflag v1.0.5 // indirect
 	go.uber.org/atomic v1.7.0 // indirect
 	go.uber.org/multierr v1.6.0 // indirect
 	go.uber.org/zap v1.24.0 // indirect
@@ -76,7 +77,6 @@ require (
 	gopkg.in/yaml.v2 v2.4.0 // indirect
 	gopkg.in/yaml.v3 v3.0.1 // indirect
 	k8s.io/apiextensions-apiserver v0.26.0 // indirect
-	k8s.io/component-base v0.26.0 // indirect
 	k8s.io/klog/v2 v2.80.1 // indirect
 	k8s.io/kube-openapi v0.0.0-20221012153701-172d655c2280 // indirect
 	sigs.k8s.io/json v0.0.0-20220713155537-f223a00ba0e2 // indirect

pkg/features/features.go

@@ -0,0 +1,21 @@
+package features
+
+import (
+	"k8s.io/component-base/featuregate"
+)
+
+const (
+// Add new feature gates constants (strings)
+// Ex: SomeFeature featuregate.Feature = "SomeFeature"
+)
+
+var catalogdFeatureGates = map[featuregate.Feature]featuregate.FeatureSpec{
+	// Add new feature gate definitions
+	// Ex: SomeFeature: {...}
+}
+
+var CatalogdFeatureGate featuregate.MutableFeatureGate = featuregate.NewFeatureGate()
+
+func init() {
+	CatalogdFeatureGate.Add(catalogdFeatureGates)
+}