Merge pull request #1258 from fluxcd/fix-flux2-5972

kustomize: support merging the input OpenAPI schemas with the built-in ones

Author: matheuscscp

kustomize/go.mod

@@ -12,12 +12,15 @@ require (
 	github.com/fluxcd/pkg/apis/kustomize v1.20.0
 	github.com/fluxcd/pkg/envsubst v1.7.0
 	github.com/fluxcd/pkg/sourceignore v0.18.0
+	github.com/google/gnostic-models v0.7.0
 	github.com/onsi/gomega v1.40.0
 	github.com/otiai10/copy v1.14.1
+	google.golang.org/protobuf v1.36.12-0.20260120151049-f2248ac996af
 	k8s.io/api v0.36.2
 	k8s.io/apiextensions-apiserver v0.36.2
 	k8s.io/apimachinery v0.36.2
 	k8s.io/client-go v0.36.2
+	k8s.io/kube-openapi v0.0.0-20260603220949-865597e52e25
 	sigs.k8s.io/controller-runtime v0.24.1
 	sigs.k8s.io/kustomize/api v0.21.1
 	sigs.k8s.io/kustomize/kyaml v0.21.1
@@ -46,13 +49,21 @@ require (
 	github.com/go-logr/logr v1.4.3 // indirect
 	github.com/go-openapi/jsonpointer v0.21.0 // indirect
 	github.com/go-openapi/jsonreference v0.21.0 // indirect
-	github.com/go-openapi/swag v0.23.0 // indirect
-	github.com/google/gnostic-models v0.7.0 // indirect
+	github.com/go-openapi/swag v0.25.4 // indirect
+	github.com/go-openapi/swag/cmdutils v0.25.4 // indirect
+	github.com/go-openapi/swag/conv v0.25.4 // indirect
+	github.com/go-openapi/swag/fileutils v0.25.4 // indirect
+	github.com/go-openapi/swag/jsonname v0.25.4 // indirect
+	github.com/go-openapi/swag/jsonutils v0.25.4 // indirect
+	github.com/go-openapi/swag/loading v0.25.4 // indirect
+	github.com/go-openapi/swag/mangling v0.25.4 // indirect
+	github.com/go-openapi/swag/netutils v0.25.4 // indirect
+	github.com/go-openapi/swag/stringutils v0.25.4 // indirect
+	github.com/go-openapi/swag/typeutils v0.25.4 // indirect
+	github.com/go-openapi/swag/yamlutils v0.25.4 // indirect
 	github.com/google/go-cmp v0.7.0 // indirect
 	github.com/google/uuid v1.6.0 // indirect
-	github.com/josharian/intern v1.0.0 // indirect
 	github.com/json-iterator/go v1.1.12 // indirect
-	github.com/mailru/easyjson v0.9.0 // indirect
 	github.com/modern-go/concurrent v0.0.0-20180306012644-bacd9c7ef1dd // indirect
 	github.com/modern-go/reflect2 v1.0.3-0.20250322232337-35a7c28c31ee // indirect
 	github.com/monochromegane/go-gitignore v0.0.0-20200626010858-205db1a8cc00 // indirect
@@ -63,7 +74,7 @@ require (
 	github.com/prometheus/client_model v0.6.2 // indirect
 	github.com/prometheus/common v0.67.5 // indirect
 	github.com/prometheus/procfs v0.19.2 // indirect
-	github.com/spf13/pflag v1.0.9 // indirect
+	github.com/spf13/pflag v1.0.10 // indirect
 	github.com/x448/float16 v0.8.4 // indirect
 	github.com/xlab/treeprint v1.2.0 // indirect
 	go.yaml.in/yaml/v2 v2.4.3 // indirect
@@ -75,12 +86,9 @@ require (
 	golang.org/x/term v0.42.0 // indirect
 	golang.org/x/text v0.36.0 // indirect
 	golang.org/x/time v0.14.0 // indirect
-	google.golang.org/protobuf v1.36.12-0.20260120151049-f2248ac996af // indirect
 	gopkg.in/evanphx/json-patch.v4 v4.13.0 // indirect
 	gopkg.in/inf.v0 v0.9.1 // indirect
-	gopkg.in/yaml.v3 v3.0.1 // indirect
 	k8s.io/klog/v2 v2.140.0 // indirect
-	k8s.io/kube-openapi v0.0.0-20260317180543-43fb72c5454a // indirect
 	k8s.io/utils v0.0.0-20260210185600-b8788abfbbc2 // indirect
 	sigs.k8s.io/json v0.0.0-20250730193827-2d320260d730 // indirect
 	sigs.k8s.io/randfill v1.0.0 // indirect

kustomize/go.sum

@@ -28,8 +28,36 @@ github.com/go-openapi/jsonpointer v0.21.0 h1:YgdVicSA9vH5RiHs9TZW5oyafXZFc6+2Vc1
 github.com/go-openapi/jsonpointer v0.21.0/go.mod h1:IUyH9l/+uyhIYQ/PXVA41Rexl+kOkAPDdXEYns6fzUY=
 github.com/go-openapi/jsonreference v0.21.0 h1:Rs+Y7hSXT83Jacb7kFyjn4ijOuVGSvOdF2+tg1TRrwQ=
 github.com/go-openapi/jsonreference v0.21.0/go.mod h1:LmZmgsrTkVg9LG4EaHeY8cBDslNPMo06cago5JNLkm4=
-github.com/go-openapi/swag v0.23.0 h1:vsEVJDUo2hPJ2tu0/Xc+4noaxyEffXNIs3cOULZ+GrE=
-github.com/go-openapi/swag v0.23.0/go.mod h1:esZ8ITTYEsH1V2trKHjAN8Ai7xHb8RV+YSZ577vPjgQ=
+github.com/go-openapi/swag v0.25.4 h1:OyUPUFYDPDBMkqyxOTkqDYFnrhuhi9NR6QVUvIochMU=
+github.com/go-openapi/swag v0.25.4/go.mod h1:zNfJ9WZABGHCFg2RnY0S4IOkAcVTzJ6z2Bi+Q4i6qFQ=
+github.com/go-openapi/swag/cmdutils v0.25.4 h1:8rYhB5n6WawR192/BfUu2iVlxqVR9aRgGJP6WaBoW+4=
+github.com/go-openapi/swag/cmdutils v0.25.4/go.mod h1:pdae/AFo6WxLl5L0rq87eRzVPm/XRHM3MoYgRMvG4A0=
+github.com/go-openapi/swag/conv v0.25.4 h1:/Dd7p0LZXczgUcC/Ikm1+YqVzkEeCc9LnOWjfkpkfe4=
+github.com/go-openapi/swag/conv v0.25.4/go.mod h1:3LXfie/lwoAv0NHoEuY1hjoFAYkvlqI/Bn5EQDD3PPU=
+github.com/go-openapi/swag/fileutils v0.25.4 h1:2oI0XNW5y6UWZTC7vAxC8hmsK/tOkWXHJQH4lKjqw+Y=
+github.com/go-openapi/swag/fileutils v0.25.4/go.mod h1:cdOT/PKbwcysVQ9Tpr0q20lQKH7MGhOEb6EwmHOirUk=
+github.com/go-openapi/swag/jsonname v0.25.4 h1:bZH0+MsS03MbnwBXYhuTttMOqk+5KcQ9869Vye1bNHI=
+github.com/go-openapi/swag/jsonname v0.25.4/go.mod h1:GPVEk9CWVhNvWhZgrnvRA6utbAltopbKwDu8mXNUMag=
+github.com/go-openapi/swag/jsonutils v0.25.4 h1:VSchfbGhD4UTf4vCdR2F4TLBdLwHyUDTd1/q4i+jGZA=
+github.com/go-openapi/swag/jsonutils v0.25.4/go.mod h1:7OYGXpvVFPn4PpaSdPHJBtF0iGnbEaTk8AvBkoWnaAY=
+github.com/go-openapi/swag/jsonutils/fixtures_test v0.25.4 h1:IACsSvBhiNJwlDix7wq39SS2Fh7lUOCJRmx/4SN4sVo=
+github.com/go-openapi/swag/jsonutils/fixtures_test v0.25.4/go.mod h1:Mt0Ost9l3cUzVv4OEZG+WSeoHwjWLnarzMePNDAOBiM=
+github.com/go-openapi/swag/loading v0.25.4 h1:jN4MvLj0X6yhCDduRsxDDw1aHe+ZWoLjW+9ZQWIKn2s=
+github.com/go-openapi/swag/loading v0.25.4/go.mod h1:rpUM1ZiyEP9+mNLIQUdMiD7dCETXvkkC30z53i+ftTE=
+github.com/go-openapi/swag/mangling v0.25.4 h1:2b9kBJk9JvPgxr36V23FxJLdwBrpijI26Bx5JH4Hp48=
+github.com/go-openapi/swag/mangling v0.25.4/go.mod h1:6dxwu6QyORHpIIApsdZgb6wBk/DPU15MdyYj/ikn0Hg=
+github.com/go-openapi/swag/netutils v0.25.4 h1:Gqe6K71bGRb3ZQLusdI8p/y1KLgV4M/k+/HzVSqT8H0=
+github.com/go-openapi/swag/netutils v0.25.4/go.mod h1:m2W8dtdaoX7oj9rEttLyTeEFFEBvnAx9qHd5nJEBzYg=
+github.com/go-openapi/swag/stringutils v0.25.4 h1:O6dU1Rd8bej4HPA3/CLPciNBBDwZj9HiEpdVsb8B5A8=
+github.com/go-openapi/swag/stringutils v0.25.4/go.mod h1:GTsRvhJW5xM5gkgiFe0fV3PUlFm0dr8vki6/VSRaZK0=
+github.com/go-openapi/swag/typeutils v0.25.4 h1:1/fbZOUN472NTc39zpa+YGHn3jzHWhv42wAJSN91wRw=
+github.com/go-openapi/swag/typeutils v0.25.4/go.mod h1:Ou7g//Wx8tTLS9vG0UmzfCsjZjKhpjxayRKTHXf2pTE=
+github.com/go-openapi/swag/yamlutils v0.25.4 h1:6jdaeSItEUb7ioS9lFoCZ65Cne1/RZtPBZ9A56h92Sw=
+github.com/go-openapi/swag/yamlutils v0.25.4/go.mod h1:MNzq1ulQu+yd8Kl7wPOut/YHAAU/H6hL91fF+E2RFwc=
+github.com/go-openapi/testify/enable/yaml/v2 v2.0.2 h1:0+Y41Pz1NkbTHz8NngxTuAXxEodtNSI1WG1c/m5Akw4=
+github.com/go-openapi/testify/enable/yaml/v2 v2.0.2/go.mod h1:kme83333GCtJQHXQ8UKX3IBZu6z8T5Dvy5+CW3NLUUg=
+github.com/go-openapi/testify/v2 v2.0.2 h1:X999g3jeLcoY8qctY/c/Z8iBHTbwLz7R2WXd6Ub6wls=
+github.com/go-openapi/testify/v2 v2.0.2/go.mod h1:HCPmvFFnheKK2BuwSA0TbbdxJ3I16pjwMkYkP4Ywn54=
 github.com/go-task/slim-sprig/v3 v3.0.0 h1:sUs3vkvUymDpBKi3qH1YSqBQk9+9D/8M2mN1vB6EwHI=
 github.com/go-task/slim-sprig/v3 v3.0.0/go.mod h1:W848ghGpv3Qj3dhTPRyJypKRiqCdHZiAzKg9hl15HA8=
 github.com/google/gnostic-models v0.7.0 h1:qwTtogB15McXDaNqTZdzPJRHvaVJlAl+HVQnLmJEJxo=
@@ -41,16 +69,12 @@ github.com/google/pprof v0.0.0-20250403155104-27863c87afa6 h1:BHT72Gu3keYf3ZEu2J
 github.com/google/pprof v0.0.0-20250403155104-27863c87afa6/go.mod h1:boTsfXsheKC2y+lKOCMpSfarhxDeIzfZG1jqGcPl3cA=
 github.com/google/uuid v1.6.0 h1:NIvaJDMOsjHA8n1jAhLSgzrAzy1Hgr+hNrb57e+94F0=
 github.com/google/uuid v1.6.0/go.mod h1:TIyPZe4MgqvfeYDBFedMoGGpEw/LqOeaOT+nhxU+yHo=
-github.com/josharian/intern v1.0.0 h1:vlS4z54oSdjm0bgjRigI+G1HpF+tI+9rE5LLzOg8HmY=
-github.com/josharian/intern v1.0.0/go.mod h1:5DoeVV0s6jJacbCEi61lwdGj/aVlrQvzHFFd8Hwg//Y=
 github.com/json-iterator/go v1.1.12 h1:PV8peI4a0ysnczrg+LtxykD8LfKY9ML6u2jnxaEnrnM=
 github.com/json-iterator/go v1.1.12/go.mod h1:e30LSqwooZae/UwlEbR2852Gd8hjQvJoHmT4TnhNGBo=
 github.com/kr/pretty v0.3.1 h1:flRD4NNwYAUpkphVc1HcthR4KEIFJ65n8Mw5qdRn3LE=
 github.com/kr/pretty v0.3.1/go.mod h1:hoEshYVHaxMs3cyo3Yncou5ZscifuDolrwPKZanG3xk=
 github.com/kr/text v0.2.0 h1:5Nx0Ya0ZqY2ygV366QzturHI13Jq95ApcVaJBhpS+AY=
 github.com/kr/text v0.2.0/go.mod h1:eLer722TekiGuMkidMxC/pM04lWEeraHUUmBw8l2grE=
-github.com/mailru/easyjson v0.9.0 h1:PrnmzHw7262yW8sTBwxi1PdJA3Iw/EKBa8psRf7d9a4=
-github.com/mailru/easyjson v0.9.0/go.mod h1:1+xMtQp2MRNVL/V1bOzuP3aP8VNwRW55fQUto+XFtTU=
 github.com/modern-go/concurrent v0.0.0-20180228061459-e0a39a4cb421/go.mod h1:6dJC0mAP4ikYIbvyc7fijjWJddQyLn8Ig3JB5CqoB9Q=
 github.com/modern-go/concurrent v0.0.0-20180306012644-bacd9c7ef1dd h1:TRLaZ9cD/w8PVh93nsPXa1VrQ6jlwL5oN8l14QlcNfg=
 github.com/modern-go/concurrent v0.0.0-20180306012644-bacd9c7ef1dd/go.mod h1:6dJC0mAP4ikYIbvyc7fijjWJddQyLn8Ig3JB5CqoB9Q=
@@ -84,8 +108,8 @@ github.com/rogpeppe/go-internal v1.14.1 h1:UQB4HGPB6osV0SQTLymcB4TgvyWu6ZyliaW0t
 github.com/rogpeppe/go-internal v1.14.1/go.mod h1:MaRKkUm5W0goXpeCfT7UZI6fk/L7L7so1lCWt35ZSgc=
 github.com/sergi/go-diff v1.4.0 h1:n/SP9D5ad1fORl+llWyN+D6qoUETXNZARKjyY2/KVCw=
 github.com/sergi/go-diff v1.4.0/go.mod h1:A0bzQcvG0E7Rwjx0REVgAGH58e96+X0MeOfepqsbeW4=
-github.com/spf13/pflag v1.0.9 h1:9exaQaMOCwffKiiiYk6/BndUBv+iRViNW+4lEMi0PvY=
-github.com/spf13/pflag v1.0.9/go.mod h1:McXfInJRrz4CZXVZOBLb0bTZqETkiAhM9Iw0y3An2Bg=
+github.com/spf13/pflag v1.0.10 h1:4EBh2KAYBwaONj6b2Ye1GiHfwjqyROoF4RwYO+vPwFk=
+github.com/spf13/pflag v1.0.10/go.mod h1:McXfInJRrz4CZXVZOBLb0bTZqETkiAhM9Iw0y3An2Bg=
 github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
 github.com/stretchr/objx v0.5.2 h1:xuMeJ0Sdp5ZMRXx/aWO6RZxdr3beISkG5/G/aIRr3pY=
 github.com/stretchr/objx v0.5.2/go.mod h1:FRsXN1f5AsAjCGJKqEizvkpNtU+EGNCLh3NxZ/8L+MA=
@@ -148,8 +172,8 @@ k8s.io/client-go v0.36.2 h1:bfgxmFKc9CgqsgX4xKLAAdmTQlWee7Ob/HlDOrJ5TBI=
 k8s.io/client-go v0.36.2/go.mod h1:1vgO4OAlfPnoLcb+Rze2GF5rAr14w8qjrYMoyXJzQj0=
 k8s.io/klog/v2 v2.140.0 h1:Tf+J3AH7xnUzZyVVXhTgGhEKnFqye14aadWv7bzXdzc=
 k8s.io/klog/v2 v2.140.0/go.mod h1:o+/RWfJ6PwpnFn7OyAG3QnO47BFsymfEfrz6XyYSSp0=
-k8s.io/kube-openapi v0.0.0-20260317180543-43fb72c5454a h1:xCeOEAOoGYl2jnJoHkC3hkbPJgdATINPMAxaynU2Ovg=
-k8s.io/kube-openapi v0.0.0-20260317180543-43fb72c5454a/go.mod h1:uGBT7iTA6c6MvqUvSXIaYZo9ukscABYi2btjhvgKGZ0=
+k8s.io/kube-openapi v0.0.0-20260603220949-865597e52e25 h1:mPMaPMpBij2V1Wv/fR+HW124vVGXXvOSS9ver/9yjWs=
+k8s.io/kube-openapi v0.0.0-20260603220949-865597e52e25/go.mod h1:V/QaCUYDa+0QpcHhVVc5l99Uz56wEMEXBSj9oCDkNDY=
 k8s.io/utils v0.0.0-20260210185600-b8788abfbbc2 h1:AZYQSJemyQB5eRxqcPky+/7EdBj0xi3g0ZcxxJ7vbWU=
 k8s.io/utils v0.0.0-20260210185600-b8788abfbbc2/go.mod h1:xDxuJ0whA3d0I4mf/C4ppKHxXynQ+fxnkmQH0vTHnuk=
 sigs.k8s.io/controller-runtime v0.24.1 h1:miPEwrmirImAvgME1L9qebGHrOnGJoVmVdtOU9fRfo4=

kustomize/kustomize_generator.go

@@ -84,6 +84,27 @@ type Generator struct {
 // SavingOptions is a function that can be used to apply saving options to a kustomization
 type SavingOptions func(dirPath, file string, action Action) error
 
+// BuildOption configures Kustomize builds.
+type BuildOption func(*buildOptions)
+
+type buildOptions struct {
+	mergeOpenAPIPathWithBuiltins bool
+}
+
+func defaultBuildOptions() buildOptions {
+	return buildOptions{
+		mergeOpenAPIPathWithBuiltins: true,
+	}
+}
+
+// WithMergeOpenAPIPathWithBuiltins controls whether openapi.path schemas are
+// merged with Kustomize's embedded Kubernetes schema before builds.
+func WithMergeOpenAPIPathWithBuiltins(enabled bool) BuildOption {
+	return func(o *buildOptions) {
+		o.mergeOpenAPIPathWithBuiltins = enabled
+	}
+}
+
 // NewGenerator creates a new kustomize generator
 // It takes a root directory and a kustomization object
 // If the root is empty, no enforcement of the root directory will be done when handling paths.
@@ -630,12 +651,12 @@ func adaptSelector(selector *kustomize.Selector) (output *kustypes.Selector) {
 // buildMutex protects against kustomize concurrent map read/write panic
 var kustomizeBuildMutex sync.Mutex
 
-// Secure Build wraps krusty.MakeKustomizer with the following settings:
+// SecureBuild wraps krusty.MakeKustomizer with the following settings:
 //   - secure on-disk FS denying operations outside root
 //   - load files from outside the kustomization dir path
 //     (but not outside root)
 //   - disable plugins except for the builtin ones
-func SecureBuild(root, dirPath string, allowRemoteBases bool) (res resmap.ResMap, err error) {
+func SecureBuild(root, dirPath string, allowRemoteBases bool, opts ...BuildOption) (res resmap.ResMap, err error) {
 	var fs filesys.FileSystem
 
 	// Create secure FS for root with or without remote base support
@@ -650,13 +671,13 @@ func SecureBuild(root, dirPath string, allowRemoteBases bool) (res resmap.ResMap
 			return nil, err
 		}
 	}
-	return Build(fs, dirPath)
+	return Build(fs, dirPath, opts...)
 }
 
 // Build wraps krusty.MakeKustomizer with the following settings:
 // - load files from outside the kustomization.yaml root
 // - disable plugins except for the builtin ones
-func Build(fs filesys.FileSystem, dirPath string) (res resmap.ResMap, err error) {
+func Build(fs filesys.FileSystem, dirPath string, opts ...BuildOption) (res resmap.ResMap, err error) {
 	// temporary workaround for concurrent map read and map write bug
 	// https://github.com/kubernetes-sigs/kustomize/issues/3659
 	kustomizeBuildMutex.Lock()
@@ -676,12 +697,23 @@ func Build(fs filesys.FileSystem, dirPath string) (res resmap.ResMap, err error)
 		PluginConfig:     kustypes.DisabledPluginConfig(),
 	}
 
+	buildOpts := defaultBuildOptions()
+	for _, opt := range opts {
+		opt(&buildOpts)
+	}
+
 	// Reset the global OpenAPI schema to ensure each build is isolated.
 	// This prevents a custom openapi configuration in one Kustomization
 	// from affecting subsequent builds (e.g., causing strategic-merge
 	// patches to fail for types omitted from the custom schema).
 	openapi.ResetOpenAPI()
 
+	if buildOpts.mergeOpenAPIPathWithBuiltins {
+		if err := mergeOpenAPIPathWithBuiltins(fs, dirPath); err != nil {
+			return nil, err
+		}
+	}
+
 	k := krusty.MakeKustomizer(buildOptions)
 	return k.Run(fs, dirPath)
 }