feat: add WithInMemoryBuild to use virtual FS for kustomize

Signed-off-by: rycli <cyril@ryc.li>

cmd/flux/build_kustomization.go

@@ -72,6 +72,7 @@ type buildKsFlags struct {
 	strictSubst       bool
 	recursive         bool
 	localSources      map[string]string
+	inMemoryBuild     bool
 }
 
 var buildKsArgs buildKsFlags
@@ -85,6 +86,8 @@ func init() {
 		"When enabled, the post build substitutions will fail if a var without a default value is declared in files but is missing from the input vars.")
 	buildKsCmd.Flags().BoolVarP(&buildKsArgs.recursive, "recursive", "r", false, "Recursively build Kustomizations")
 	buildKsCmd.Flags().StringToStringVar(&buildKsArgs.localSources, "local-sources", nil, "Comma-separated list of repositories in format: Kind/namespace/name=path")
+	buildKsCmd.Flags().BoolVar(&buildKsArgs.inMemoryBuild, "in-memory-build", true,
+		"Use in-memory filesystem during build.")
 	buildCmd.AddCommand(buildKsCmd)
 }
 
@@ -130,6 +133,7 @@ func buildKsCmdRun(cmd *cobra.Command, args []string) (err error) {
 			build.WithStrictSubstitute(buildKsArgs.strictSubst),
 			build.WithRecursive(buildKsArgs.recursive),
 			build.WithLocalSources(buildKsArgs.localSources),
+			build.WithInMemoryBuild(buildKsArgs.inMemoryBuild),
 		)
 	} else {
 		builder, err = build.NewBuilder(name, buildKsArgs.path,
@@ -140,6 +144,7 @@ func buildKsCmdRun(cmd *cobra.Command, args []string) (err error) {
 			build.WithStrictSubstitute(buildKsArgs.strictSubst),
 			build.WithRecursive(buildKsArgs.recursive),
 			build.WithLocalSources(buildKsArgs.localSources),
+			build.WithInMemoryBuild(buildKsArgs.inMemoryBuild),
 		)
 	}
 

cmd/flux/build_kustomization_test.go

@@ -52,6 +52,12 @@ func TestBuildKustomization(t *testing.T) {
 			resultFile: "./testdata/build-kustomization/podinfo-result.yaml",
 			assertFunc: "assertGoldenTemplateFile",
 		},
+		{
+			name:       "build podinfo (on-disk)",
+			args:       "build kustomization podinfo --path ./testdata/build-kustomization/podinfo --in-memory-build=false",
+			resultFile: "./testdata/build-kustomization/podinfo-result.yaml",
+			assertFunc: "assertGoldenTemplateFile",
+		},
 		{
 			name:       "build podinfo without service",
 			args:       "build kustomization podinfo --path ./testdata/build-kustomization/delete-service",
@@ -70,12 +76,24 @@ func TestBuildKustomization(t *testing.T) {
 			resultFile: "./testdata/build-kustomization/podinfo-with-ignore-result.yaml",
 			assertFunc: "assertGoldenTemplateFile",
 		},
+		{
+			name:       "build ignore (on-disk)",
+			args:       "build kustomization podinfo --path ./testdata/build-kustomization/ignore --ignore-paths \"!configmap.yaml,!secret.yaml\" --in-memory-build=false",
+			resultFile: "./testdata/build-kustomization/podinfo-with-ignore-result.yaml",
+			assertFunc: "assertGoldenTemplateFile",
+		},
 		{
 			name:       "build with recursive",
 			args:       "build kustomization podinfo --path ./testdata/build-kustomization/podinfo-with-my-app --recursive --local-sources GitRepository/default/podinfo=./testdata/build-kustomization",
 			resultFile: "./testdata/build-kustomization/podinfo-with-my-app-result.yaml",
 			assertFunc: "assertGoldenTemplateFile",
 		},
+		{
+			name:       "build with recursive (on-disk)",
+			args:       "build kustomization podinfo --path ./testdata/build-kustomization/podinfo-with-my-app --recursive --local-sources GitRepository/default/podinfo=./testdata/build-kustomization --in-memory-build=false",
+			resultFile: "./testdata/build-kustomization/podinfo-with-my-app-result.yaml",
+			assertFunc: "assertGoldenTemplateFile",
+		},
 	}
 
 	tmpl := map[string]string{
@@ -145,6 +163,12 @@ spec:
 			resultFile: "./testdata/build-kustomization/podinfo-result.yaml",
 			assertFunc: "assertGoldenTemplateFile",
 		},
+		{
+			name:       "build podinfo (on-disk)",
+			args:       "build kustomization podinfo --kustomization-file " + tmpFile + " --path ./testdata/build-kustomization/podinfo --in-memory-build=false",
+			resultFile: "./testdata/build-kustomization/podinfo-result.yaml",
+			assertFunc: "assertGoldenTemplateFile",
+		},
 		{
 			name:       "build podinfo without service",
 			args:       "build kustomization podinfo --kustomization-file " + tmpFile + " --path ./testdata/build-kustomization/delete-service",
@@ -175,6 +199,18 @@ spec:
 			resultFile: "./testdata/build-kustomization/podinfo-with-my-app-result.yaml",
 			assertFunc: "assertGoldenTemplateFile",
 		},
+		{
+			name:       "build with recursive (on-disk)",
+			args:       "build kustomization podinfo --kustomization-file " + tmpFile + " --path ./testdata/build-kustomization/podinfo-with-my-app --recursive --local-sources GitRepository/default/podinfo=./testdata/build-kustomization --in-memory-build=false",
+			resultFile: "./testdata/build-kustomization/podinfo-with-my-app-result.yaml",
+			assertFunc: "assertGoldenTemplateFile",
+		},
+		{
+			name:       "build with recursive in dry-run mode (on-disk)",
+			args:       "build kustomization podinfo --kustomization-file " + tmpFile + " --path ./testdata/build-kustomization/podinfo-with-my-app --recursive --local-sources GitRepository/default/podinfo=./testdata/build-kustomization --in-memory-build=false --dry-run",
+			resultFile: "./testdata/build-kustomization/podinfo-with-my-app-result.yaml",
+			assertFunc: "assertGoldenTemplateFile",
+		},
 	}
 
 	tmpl := map[string]string{
@@ -241,6 +277,12 @@ func TestBuildKustomizationPathNormalization(t *testing.T) {
 			resultFile: "./testdata/build-kustomization/podinfo-result.yaml",
 			assertFunc: "assertGoldenTemplateFile",
 		},
+		{
+			name:       "build with absolute path (on-disk)",
+			args:       "build kustomization podinfo --path " + absTestDataPath + " --in-memory-build=false",
+			resultFile: "./testdata/build-kustomization/podinfo-result.yaml",
+			assertFunc: "assertGoldenTemplateFile",
+		},
 		{
 			name:       "build with complex relative path (parent dir)",
 			args:       "build kustomization podinfo --path ./testdata/build-kustomization/../build-kustomization/podinfo",

cmd/flux/diff_kustomization.go

@@ -62,6 +62,7 @@ type diffKsFlags struct {
 	strictSubst       bool
 	recursive         bool
 	localSources      map[string]string
+	inMemoryBuild     bool
 }
 
 var diffKsArgs diffKsFlags
@@ -75,6 +76,8 @@ func init() {
 		"When enabled, the post build substitutions will fail if a var without a default value is declared in files but is missing from the input vars.")
 	diffKsCmd.Flags().BoolVarP(&diffKsArgs.recursive, "recursive", "r", false, "Recursively diff Kustomizations")
 	diffKsCmd.Flags().StringToStringVar(&diffKsArgs.localSources, "local-sources", nil, "Comma-separated list of repositories in format: Kind/namespace/name=path")
+	diffKsCmd.Flags().BoolVar(&diffKsArgs.inMemoryBuild, "in-memory-build", true,
+		"Use in-memory filesystem during build.")
 	diffCmd.AddCommand(diffKsCmd)
 }
 
@@ -113,6 +116,7 @@ func diffKsCmdRun(cmd *cobra.Command, args []string) error {
 			build.WithRecursive(diffKsArgs.recursive),
 			build.WithLocalSources(diffKsArgs.localSources),
 			build.WithSingleKustomization(),
+			build.WithInMemoryBuild(diffKsArgs.inMemoryBuild),
 		)
 	} else {
 		builder, err = build.NewBuilder(name, diffKsArgs.path,
@@ -124,6 +128,7 @@ func diffKsCmdRun(cmd *cobra.Command, args []string) error {
 			build.WithRecursive(diffKsArgs.recursive),
 			build.WithLocalSources(diffKsArgs.localSources),
 			build.WithSingleKustomization(),
+			build.WithInMemoryBuild(diffKsArgs.inMemoryBuild),
 		)
 	}