Workaround for kustomize build panic

Serialize kustomize build runs to avoid kyaml OpenAPI concurrent map read/write panic
kubernetes-sigs/kustomize#3659

Signed-off-by: Stefan Prodan <stefan.prodan@gmail.com>

controllers/kustomization_generator.go

@@ -25,6 +25,7 @@ import (
  "os"
  "path/filepath"
  "strings"
+ "sync"
 
  "sigs.k8s.io/controller-runtime/pkg/client"
  "sigs.k8s.io/kustomize/api/filesys"
@@ -333,11 +334,19 @@ func adaptSelector(selector *kustomize.Selector) (output *kustypes.Selector) {
  return
 }
 
+// TODO: remove mutex when kustomize fixes the concurrent map read/write panic
+var kustomizeBuildMutex sync.Mutex
+
 // buildKustomization wraps krusty.MakeKustomizer with the following settings:
 // - reorder the resources just before output (Namespaces and Cluster roles/role bindings first, CRDs before CRs, Webhooks last)
 // - load files from outside the kustomization.yaml root
 // - disable plugins except for the builtin ones
 func buildKustomization(fs filesys.FileSystem, dirPath string) (resmap.ResMap, error) {
+ // temporary workaround for concurrent map read and map write bug
+ // https://github.com/kubernetes-sigs/kustomize/issues/3659
+ kustomizeBuildMutex.Lock()
+ defer kustomizeBuildMutex.Unlock()
+
  buildOptions := &krusty.Options{
  DoLegacyResourceSort: true,
  LoadRestrictions: kustypes.LoadRestrictionsNone,