Merge pull request #718 from fluxcd/restore-emptydir-build

kustomize: Restore empty dir build

kustomize/go.mod

@@ -11,16 +11,15 @@ require (
 	github.com/drone/envsubst v1.0.3
 	github.com/fluxcd/pkg/apis/kustomize v1.2.0
 	github.com/fluxcd/pkg/sourceignore v0.4.0
-	github.com/go-git/go-git/v5 v5.10.1
-	github.com/hashicorp/go-multierror v1.1.1
+	github.com/go-git/go-git/v5 v5.11.0
 	github.com/onsi/gomega v1.30.0
 	github.com/otiai10/copy v1.14.0
 	k8s.io/api v0.28.4
 	k8s.io/apiextensions-apiserver v0.28.4
 	k8s.io/apimachinery v0.28.4
 	k8s.io/client-go v0.28.4
 	sigs.k8s.io/controller-runtime v0.16.3
-	sigs.k8s.io/kustomize/api v0.15.0
+	sigs.k8s.io/kustomize/api v0.16.0
 	sigs.k8s.io/kustomize/kyaml v0.16.0
 	sigs.k8s.io/yaml v1.4.0
 )
@@ -52,7 +51,6 @@ require (
 	github.com/google/gofuzz v1.2.0 // indirect
 	github.com/google/shlex v0.0.0-20191202100458-e7afc7fbc510 // indirect
 	github.com/google/uuid v1.4.0 // indirect
-	github.com/hashicorp/errwrap v1.1.0 // indirect
 	github.com/imdario/mergo v0.3.15 // indirect
 	github.com/jbenet/go-context v0.0.0-20150711004518-d14ea06fba99 // indirect
 	github.com/josharian/intern v1.0.0 // indirect
@@ -69,7 +67,6 @@ require (
 	github.com/prometheus/common v0.45.0 // indirect
 	github.com/prometheus/procfs v0.12.0 // indirect
 	github.com/spf13/pflag v1.0.5 // indirect
-	github.com/stretchr/testify v1.8.4 // indirect
 	github.com/xlab/treeprint v1.2.0 // indirect
 	go.starlark.net v0.0.0-20230525235612-a134d8f9ddca // indirect
 	golang.org/x/net v0.19.0 // indirect

kustomize/go.sum

@@ -26,8 +26,8 @@ github.com/go-git/gcfg v1.5.1-0.20230307220236-3a3c6141e376 h1:+zs/tPmkDkHx3U66D
 github.com/go-git/gcfg v1.5.1-0.20230307220236-3a3c6141e376/go.mod h1:an3vInlBmSxCcxctByoQdvwPiA7DTK7jaaFDBTtu0ic=
 github.com/go-git/go-billy/v5 v5.5.0 h1:yEY4yhzCDuMGSv83oGxiBotRzhwhNr8VZyphhiu+mTU=
 github.com/go-git/go-billy/v5 v5.5.0/go.mod h1:hmexnoNsr2SJU1Ju67OaNz5ASJY3+sHgFRpCtpDCKow=
-github.com/go-git/go-git/v5 v5.10.1 h1:tu8/D8i+TWxgKpzQ3Vc43e+kkhXqtsZCKI/egajKnxk=
-github.com/go-git/go-git/v5 v5.10.1/go.mod h1:uEuHjxkHap8kAl//V5F/nNWwqIYtP/402ddd05mp0wg=
+github.com/go-git/go-git/v5 v5.11.0 h1:XIZc1p+8YzypNr34itUfSvYJcv+eYdTnTvOZ2vD3cA4=
+github.com/go-git/go-git/v5 v5.11.0/go.mod h1:6GFcX2P3NM7FPBfpePbpLd21XxsgdAt+lKqXmCUiUCY=
 github.com/go-logr/logr v1.2.0/go.mod h1:jdQByPbusPIv2/zmleS9BjJVeZ6kBagPoEUsqbVz/1A=
 github.com/go-logr/logr v1.3.0 h1:2y3SDp0ZXuc6/cjLSZ+Q3ir+QB9T/iG5yYRXqsagWSY=
 github.com/go-logr/logr v1.3.0/go.mod h1:9T104GzyrTigFIr8wt5mBrctHMim0Nb2HLGrmQ40KvY=
@@ -76,11 +76,6 @@ github.com/google/shlex v0.0.0-20191202100458-e7afc7fbc510 h1:El6M4kTTCOh6aBiKaU
 github.com/google/shlex v0.0.0-20191202100458-e7afc7fbc510/go.mod h1:pupxD2MaaD3pAXIBCelhxNneeOaAeabZDe5s4K6zSpQ=
 github.com/google/uuid v1.4.0 h1:MtMxsa51/r9yyhkyLsVeVt0B+BGQZzpQiTQ4eHZ8bc4=
 github.com/google/uuid v1.4.0/go.mod h1:TIyPZe4MgqvfeYDBFedMoGGpEw/LqOeaOT+nhxU+yHo=
-github.com/hashicorp/errwrap v1.0.0/go.mod h1:YH+1FKiLXxHSkmPseP+kNlulaMuP3n2brvKWEqk/Jc4=
-github.com/hashicorp/errwrap v1.1.0 h1:OxrOeh75EUXMY8TBjag2fzXGZ40LB6IKw45YeGUDY2I=
-github.com/hashicorp/errwrap v1.1.0/go.mod h1:YH+1FKiLXxHSkmPseP+kNlulaMuP3n2brvKWEqk/Jc4=
-github.com/hashicorp/go-multierror v1.1.1 h1:H5DkEtf6CXdFp0N0Em5UCwQpXMWke8IA0+lD48awMYo=
-github.com/hashicorp/go-multierror v1.1.1/go.mod h1:iw975J/qwKPdAO1clOe2L8331t/9/fmwbPZ6JB6eMoM=
 github.com/imdario/mergo v0.3.15 h1:M8XP7IuFNsqUx6VPK2P9OSmsYsI/YFaGil0uD21V3dM=
 github.com/imdario/mergo v0.3.15/go.mod h1:WBLT9ZmE3lPoWsEzCh9LPo3TiwVN+ZKEjmz+hD27ysY=
 github.com/jbenet/go-context v0.0.0-20150711004518-d14ea06fba99 h1:BQSFePA1RWJOlocH6Fxy8MmwDt+yVQYULKfN0RoTN8A=
@@ -144,7 +139,6 @@ github.com/stretchr/testify v1.7.1/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/
 github.com/stretchr/testify v1.8.0/go.mod h1:yNjHg4UonilssWZ8iaSj1OCr/vHnekPRkoO+kdMU+MU=
 github.com/stretchr/testify v1.8.1/go.mod h1:w2LPCIKwWwSfY2zedu0+kehJoqGctiVI29o6fzry7u4=
 github.com/stretchr/testify v1.8.4 h1:CcVxjf3Q8PM0mHUKJCdn+eZZtm5yQwehR5yeSVQQcUk=
-github.com/stretchr/testify v1.8.4/go.mod h1:sz/lmYIOXD/1dqDmKjjqLyZ2RngseejIcXlSw2iwfAo=
 github.com/xlab/treeprint v1.2.0 h1:HzHnuAF1plUN2zGlAFHbSQP2qJ0ZAD3XF5XD7OesXRQ=
 github.com/xlab/treeprint v1.2.0/go.mod h1:gj5Gd3gPdKtR1ikdDK6fnFLdmIS0X30kTTuNd/WEJu0=
 github.com/yuin/goldmark v1.1.27/go.mod h1:3hX8gzYuyVAZsxl0MRgGTJEmQBFcNTphYh9decYSb74=

kustomize/kustomize_generator.go

@@ -18,6 +18,7 @@ package kustomize
 
 import (
 	"encoding/json"
+	"errors"
 	"fmt"
 	"io"
 	"os"
@@ -26,7 +27,6 @@ import (
 	"strings"
 	"sync"
 
-	securefs "github.com/fluxcd/pkg/kustomize/filesys"
 	apiextensionsv1 "k8s.io/apiextensions-apiserver/pkg/apis/apiextensions/v1"
 	"k8s.io/apimachinery/pkg/apis/meta/v1/unstructured"
 	"k8s.io/apimachinery/pkg/runtime"
@@ -39,7 +39,7 @@ import (
 	"sigs.k8s.io/yaml"
 
 	"github.com/fluxcd/pkg/apis/kustomize"
-	"github.com/hashicorp/go-multierror"
+	securefs "github.com/fluxcd/pkg/kustomize/filesys"
 )
 
 const (
@@ -274,12 +274,12 @@ func (g *Generator) getPatches() ([]kustomize.Patch, error) {
 			patch, ok := p.(map[string]interface{})
 			if !ok {
 				err := fmt.Errorf("unable to convert patch %d to map[string]interface{}", k)
-				resultErr = multierror.Append(resultErr, err)
+				resultErr = errors.Join(resultErr, err)
 			}
 			var kpatch kustomize.Patch
 			err = runtime.DefaultUnstructuredConverter.FromUnstructured(patch, &kpatch)
 			if err != nil {
-				resultErr = multierror.Append(resultErr, err)
+				resultErr = errors.Join(resultErr, err)
 			}
 			res = append(res, kpatch)
 		}
@@ -303,12 +303,12 @@ func (g *Generator) getPatchesStrategicMerge() ([]apiextensionsv1.JSON, error) {
 			patch, ok := p.(map[string]interface{})
 			if !ok {
 				err := fmt.Errorf("unable to convert patch %d to map[string]interface{}", k)
-				resultErr = multierror.Append(resultErr, err)
+				resultErr = errors.Join(resultErr, err)
 			}
 			var kpatch apiextensionsv1.JSON
 			err = runtime.DefaultUnstructuredConverter.FromUnstructured(patch, &kpatch)
 			if err != nil {
-				resultErr = multierror.Append(resultErr, err)
+				resultErr = errors.Join(resultErr, err)
 			}
 			res = append(res, kpatch)
 		}
@@ -332,12 +332,12 @@ func (g *Generator) getPatchesJson6902() ([]kustomize.JSON6902Patch, error) {
 			patch, ok := p.(map[string]interface{})
 			if !ok {
 				err := fmt.Errorf("unable to convert patch %d to map[string]interface{}", k)
-				resultErr = multierror.Append(resultErr, err)
+				resultErr = errors.Join(resultErr, err)
 			}
 			var kpatch kustomize.JSON6902Patch
 			err = runtime.DefaultUnstructuredConverter.FromUnstructured(patch, &kpatch)
 			if err != nil {
-				resultErr = multierror.Append(resultErr, err)
+				resultErr = errors.Join(resultErr, err)
 			}
 			res = append(res, kpatch)
 		}
@@ -361,12 +361,12 @@ func (g *Generator) getImages() ([]kustomize.Image, error) {
 			im, ok := i.(map[string]interface{})
 			if !ok {
 				err := fmt.Errorf("unable to convert patch %d to map[string]interface{}", k)
-				resultErr = multierror.Append(resultErr, err)
+				resultErr = errors.Join(resultErr, err)
 			}
 			var image kustomize.Image
 			err = runtime.DefaultUnstructuredConverter.FromUnstructured(im, &image)
 			if err != nil {
-				resultErr = multierror.Append(resultErr, err)
+				resultErr = errors.Join(resultErr, err)
 			}
 			res = append(res, image)
 		}
@@ -467,7 +467,14 @@ func (g *Generator) generateKustomization(dirPath string) (Action, string, error
 		resources = append(resources, strings.Replace(file, abs, ".", 1))
 	}
 
-	kus.Resources = resources
+	if len(resources) == 0 {
+		// if there are no resources, set a placeholder namespace
+		// to avoid "kustomization.yaml is empty" build error
+		kus.Namespace = "_placeholder"
+	} else {
+		kus.Resources = resources
+	}
+
 	kd, err := yaml.Marshal(kus)
 	if err != nil {
 		// delete the kustomization file

kustomize/kustomize_generator_test.go

@@ -23,18 +23,42 @@ import (
 	"strings"
 	"testing"
 
-	"github.com/fluxcd/pkg/kustomize"
 	. "github.com/onsi/gomega"
 	"github.com/otiai10/copy"
 	"k8s.io/apimachinery/pkg/apis/meta/v1/unstructured"
 	"sigs.k8s.io/kustomize/api/resmap"
 	kustypes "sigs.k8s.io/kustomize/api/types"
 	"sigs.k8s.io/kustomize/kyaml/filesys"
 	"sigs.k8s.io/yaml"
+
+	"github.com/fluxcd/pkg/kustomize"
 )
 
 const resourcePath = "./testdata/resources/"
 
+func TestGenerator_EmptyDir(t *testing.T) {
+	g := NewWithT(t)
+	dataKS, err := os.ReadFile("./testdata/empty/ks.yaml")
+	g.Expect(err).NotTo(HaveOccurred())
+
+	ks, err := readYamlObjects(strings.NewReader(string(dataKS)))
+	g.Expect(err).NotTo(HaveOccurred())
+
+	emptyDir, err := testTempDir(t)
+	g.Expect(err).NotTo(HaveOccurred())
+
+	_, err = kustomize.NewGenerator("", ks[0]).WriteFile(emptyDir)
+	g.Expect(err).NotTo(HaveOccurred())
+
+	data, err := os.ReadFile(filepath.Join(emptyDir, "kustomization.yaml"))
+	g.Expect(err).NotTo(HaveOccurred())
+	g.Expect(string(data)).To(ContainSubstring("_placeholder"))
+
+	resMap, err := kustomize.SecureBuild(emptyDir, emptyDir, false)
+	g.Expect(err).NotTo(HaveOccurred())
+	g.Expect(resMap.Resources()).To(HaveLen(0))
+}
+
 func TestKustomizationGenerator(t *testing.T) {
 	tests := []struct {
 		name    string

kustomize/kustomize_varsub.go

@@ -18,12 +18,12 @@ package kustomize
 
 import (
 	"context"
+	"errors"
 	"fmt"
 	"regexp"
 	"strings"
 
 	"github.com/drone/envsubst"
-	"github.com/hashicorp/go-multierror"
 	corev1 "k8s.io/api/core/v1"
 	apierrors "k8s.io/apimachinery/pkg/api/errors"
 	"k8s.io/apimachinery/pkg/apis/meta/v1/unstructured"
@@ -181,12 +181,12 @@ func getSubstituteFrom(kustomization unstructured.Unstructured) ([]SubstituteRef
 			sub, ok := s.(map[string]interface{})
 			if !ok {
 				err := fmt.Errorf("unable to convert patch %d to map[string]interface{}", k)
-				resultErr = multierror.Append(resultErr, err)
+				resultErr = errors.Join(resultErr, err)
 			}
 			var substitute SubstituteReference
 			err = runtime.DefaultUnstructuredConverter.FromUnstructured(sub, &substitute)
 			if err != nil {
-				resultErr = multierror.Append(resultErr, err)
+				resultErr = errors.Join(resultErr, err)
 			}
 			res = append(res, substitute)
 		}

kustomize/testdata/empty/ks.yaml

@@ -0,0 +1,13 @@
+---
+apiVersion: kustomize.toolkit.fluxcd.io/v1
+kind: Kustomization
+metadata:
+  name: app
+  namespace: apps
+spec:
+  interval: 4m0s
+  path: ./empty
+  prune: true
+  sourceRef:
+    kind: GitRepository
+    name: app