feat(k8s): use secret as shared source for admin private key

internal/integration/integration.go

@@ -3,6 +3,7 @@ package integration
 import (
 	"context"
 
+	"forge.cadoles.com/cadoles/bouncer/internal/jwk"
 	"github.com/pkg/errors"
 )
 
@@ -15,6 +16,11 @@ type OnStartup interface {
 	OnStartup(ctx context.Context) error
 }
 
+type OnKeyLoad interface {
+	Integration
+	OnKeyLoad(ctx context.Context) (jwk.Key, error)
+}
+
 func RunOnStartup(ctx context.Context, integrations []Integration) error {
 	for _, it := range integrations {
 		onStartup, ok := it.(OnStartup)
@@ -29,3 +35,23 @@ func RunOnStartup(ctx context.Context, integrations []Integration) error {
 
 	return nil
 }
+
+func RunOnKeyLoad(ctx context.Context, integrations []Integration) (jwk.Key, error) {
+	for _, it := range integrations {
+		onKeyLoad, ok := it.(OnKeyLoad)
+		if !ok {
+			continue
+		}
+
+		key, err := onKeyLoad.OnKeyLoad(ctx)
+		if err != nil {
+			return nil, errors.WithStack(err)
+		}
+
+		if key != nil {
+			return key, nil
+		}
+	}
+
+	return nil, nil
+}