Move demandDirectoryRoot into kyaml/filesys (#4677)

* Move demandDirectoryRoot into kyaml/filesys

* Make root directory platform-agnostic

Support windows root directory. Dogfood own error package.

* Use cleaner windows support implementation

* Address feedback

* Address feedback x2

* Re-apply go.sum changes to avoid CI errors

api/go.sum

@@ -437,6 +437,7 @@ golang.org/x/sys v0.0.0-20210315160823-c6e025ad8005/go.mod h1:h1NjWce9XRLGQEsW7w
 golang.org/x/sys v0.0.0-20210320140829-1e4c9ba3b0c4/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20210330210617-4fbd30eecc44/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20210403161142-5e06dd20ab57/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/sys v0.0.0-20210510120138-977fb7262007 h1:gG67DSER+11cZvqIMb8S8bt0vZtiN6xWYARwirrOSfE=
 golang.org/x/sys v0.0.0-20210510120138-977fb7262007/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/term v0.0.0-20201126162022-7de9c90e9dd1/go.mod h1:bj7SfCRtBDWHUb9snDiAeCFNEtKQo2Wmx5Cou7ajbmo=
 golang.org/x/text v0.0.0-20170915032832-14c0d48ead0c/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=

api/internal/target/kusttarget.go

@@ -407,7 +407,7 @@ func (kt *KustTarget) accumulateResources(
 		// try loading resource as file then as base (directory or git repository)
 		if errF := kt.accumulateFile(ra, path); errF != nil {
 			// not much we can do if the error is an HTTP error so we bail out
-			if errors.Is(errF, load.ErrorHTTP) {
+			if errors.Is(errF, load.ErrHTTP) {
 				return nil, errF
 			}
 			ldr, err := kt.ldr.New(path)

api/krusty/component_test.go

@@ -9,6 +9,7 @@ import (
 	"testing"
 
 	"sigs.k8s.io/kustomize/api/konfig"
+	"sigs.k8s.io/kustomize/api/loader"
 	kusttest_test "sigs.k8s.io/kustomize/api/testutils/kusttest"
 )
 
@@ -551,7 +552,7 @@ components:
 `),
 			},
 			runPath:       "filesincomponents",
-			expectedError: "'/filesincomponents/stub.yaml' must be a directory so that it can used as a build root",
+			expectedError: fmt.Sprintf("%s: '%s'", loader.ErrRtNotDir.Error(), "/filesincomponents/stub.yaml"),
 		},
 		"invalid-component-api-version": {
 			input: []FileGen{writeTestBase, writeOverlayProd,

api/krusty/remoteload_test.go

@@ -323,7 +323,7 @@ func TestRemoteResourceWithHttpError(t *testing.T) {
 
 	_, err := b.Run(fSys, tmpDir.String())
 
-	httpErr := fmt.Errorf("%w: status code %d (%s)", loader.ErrorHTTP, 404, http.StatusText(404))
+	httpErr := fmt.Errorf("%w: status code %d (%s)", loader.ErrHTTP, 404, http.StatusText(404))
 	accuFromErr := fmt.Errorf("accumulating resources from '%s': %w", url404, httpErr)
 	expectedErr := fmt.Errorf("accumulating resources: %w", accuFromErr)
 	req.EqualErrorf(err, expectedErr.Error(), url404)

api/loader/errors.go

@@ -3,6 +3,9 @@
 
 package loader
 
-import "fmt"
+import "sigs.k8s.io/kustomize/kyaml/errors"
 
-var ErrorHTTP = fmt.Errorf("HTTP Error")
+var (
+	ErrHTTP     = errors.Errorf("HTTP Error")
+	ErrRtNotDir = errors.Errorf("must build at directory")
+)

api/loader/fileloader.go

@@ -4,7 +4,6 @@
 package loader
 
 import (
-	"errors"
 	"fmt"
 	"io/ioutil"
 	"log"
@@ -15,6 +14,7 @@ import (
 
 	"sigs.k8s.io/kustomize/api/ifc"
 	"sigs.k8s.io/kustomize/api/internal/git"
+	"sigs.k8s.io/kustomize/kyaml/errors"
 	"sigs.k8s.io/kustomize/kyaml/filesys"
 )
 
@@ -123,7 +123,7 @@ func (fl *fileLoader) Root() string {
 func newLoaderOrDie(
 	lr LoadRestrictorFunc,
 	fSys filesys.FileSystem, path string) *fileLoader {
-	root, err := demandDirectoryRoot(fSys, path)
+	root, err := filesys.ConfirmDir(fSys, path)
 	if err != nil {
 		log.Fatalf("unable to make loader at '%s'; %v", path, err)
 	}
@@ -146,30 +146,11 @@ func newLoaderAtConfirmedDir(
 	}
 }
 
-// Assure that the given path is in fact a directory.
-func demandDirectoryRoot(
-	fSys filesys.FileSystem, path string) (filesys.ConfirmedDir, error) {
-	if path == "" {
-		return "", fmt.Errorf(
-			"loader root cannot be empty")
-	}
-	d, f, err := fSys.CleanedAbs(path)
-	if err != nil {
-		return "", err
-	}
-	if f != "" {
-		return "", fmt.Errorf(
-			"'%s' must be a directory so that it can used as a build root",
-			path)
-	}
-	return d, nil
-}
-
 // New returns a new Loader, rooted relative to current loader,
 // or rooted in a temp directory holding a git repo clone.
 func (fl *fileLoader) New(path string) (ifc.Loader, error) {
 	if path == "" {
-		return nil, fmt.Errorf("new root cannot be empty")
+		return nil, errors.Errorf("new root cannot be empty")
 	}
 
 	repoSpec, err := git.NewRepoSpecFromURL(path)
@@ -185,9 +166,9 @@ func (fl *fileLoader) New(path string) (ifc.Loader, error) {
 	if filepath.IsAbs(path) {
 		return nil, fmt.Errorf("new root '%s' cannot be absolute", path)
 	}
-	root, err := demandDirectoryRoot(fl.fSys, fl.root.Join(path))
+	root, err := filesys.ConfirmDir(fl.fSys, fl.root.Join(path))
 	if err != nil {
-		return nil, err
+		return nil, errors.WrapPrefixf(err, ErrRtNotDir.Error())
 	}
 	if err = fl.errIfGitContainmentViolation(root); err != nil {
 		return nil, err
@@ -317,9 +298,9 @@ func (fl *fileLoader) Load(path string) ([]byte, error) {
 		if resp.StatusCode < 200 || resp.StatusCode > 299 {
 			_, err := git.NewRepoSpecFromURL(path)
 			if err == nil {
-				return nil, errors.New("URL is a git repository")
+				return nil, errors.Errorf("URL is a git repository")
 			}
-			return nil, fmt.Errorf("%w: status code %d (%s)", ErrorHTTP, resp.StatusCode, http.StatusText(resp.StatusCode))
+			return nil, fmt.Errorf("%w: status code %d (%s)", ErrHTTP, resp.StatusCode, http.StatusText(resp.StatusCode))
 		}
 		body, err := ioutil.ReadAll(resp.Body)
 		if err != nil {

api/loader/fileloader_test.go

@@ -15,7 +15,6 @@ import (
 	"testing"
 
 	"github.com/stretchr/testify/require"
-
 	"sigs.k8s.io/kustomize/api/ifc"
 	"sigs.k8s.io/kustomize/api/internal/git"
 	"sigs.k8s.io/kustomize/api/konfig"
@@ -408,11 +407,8 @@ func TestLocalLoaderReferencingGitBase(t *testing.T) {
 	fSys.MkdirAll(topDir)
 	fSys.MkdirAll(cloneRoot + "/foo/base")
 
-	root, err := demandDirectoryRoot(fSys, topDir)
-	require.NoError(err)
-
 	l1 := newLoaderAtConfirmedDir(
-		RestrictionRootOnly, root, fSys, nil,
+		RestrictionRootOnly, filesys.ConfirmedDir(topDir), fSys, nil,
 		git.DoNothingCloner(filesys.ConfirmedDir(cloneRoot)))
 	require.Equal(topDir, l1.Root())
 
@@ -430,11 +426,8 @@ func TestRepoDirectCycleDetection(t *testing.T) {
 	fSys.MkdirAll(topDir)
 	fSys.MkdirAll(cloneRoot)
 
-	root, err := demandDirectoryRoot(fSys, topDir)
-	require.NoError(err)
-
 	l1 := newLoaderAtConfirmedDir(
-		RestrictionRootOnly, root, fSys, nil,
+		RestrictionRootOnly, filesys.ConfirmedDir(topDir), fSys, nil,
 		git.DoNothingCloner(filesys.ConfirmedDir(cloneRoot)))
 	p1 := "github.com/someOrg/someRepo/foo"
 	rs1, err := git.NewRepoSpecFromURL(p1)
@@ -455,11 +448,8 @@ func TestRepoIndirectCycleDetection(t *testing.T) {
 	fSys.MkdirAll(topDir)
 	fSys.MkdirAll(cloneRoot)
 
-	root, err := demandDirectoryRoot(fSys, topDir)
-	require.NoError(err)
-
 	l0 := newLoaderAtConfirmedDir(
-		RestrictionRootOnly, root, fSys, nil,
+		RestrictionRootOnly, filesys.ConfirmedDir(topDir), fSys, nil,
 		git.DoNothingCloner(filesys.ConfirmedDir(cloneRoot)))
 
 	p1 := "github.com/someOrg/someRepo1"

api/loader/loader.go

@@ -7,6 +7,7 @@ package loader
 import (
 	"sigs.k8s.io/kustomize/api/ifc"
 	"sigs.k8s.io/kustomize/api/internal/git"
+	"sigs.k8s.io/kustomize/kyaml/errors"
 	"sigs.k8s.io/kustomize/kyaml/filesys"
 )
 
@@ -25,9 +26,9 @@ func NewLoader(
 		return newLoaderAtGitClone(
 			repoSpec, fSys, nil, git.ClonerUsingGitExec)
 	}
-	root, err := demandDirectoryRoot(fSys, target)
+	root, err := filesys.ConfirmDir(fSys, target)
 	if err != nil {
-		return nil, err
+		return nil, errors.WrapPrefixf(err, ErrRtNotDir.Error())
 	}
 	return newLoaderAtConfirmedDir(
 		lr, root, fSys, nil, git.ClonerUsingGitExec), nil

cmd/config/go.sum

@@ -444,6 +444,7 @@ golang.org/x/sys v0.0.0-20210315160823-c6e025ad8005/go.mod h1:h1NjWce9XRLGQEsW7w
 golang.org/x/sys v0.0.0-20210320140829-1e4c9ba3b0c4/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20210330210617-4fbd30eecc44/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20210403161142-5e06dd20ab57/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/sys v0.0.0-20210510120138-977fb7262007 h1:gG67DSER+11cZvqIMb8S8bt0vZtiN6xWYARwirrOSfE=
 golang.org/x/sys v0.0.0-20210510120138-977fb7262007/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/term v0.0.0-20201126162022-7de9c90e9dd1/go.mod h1:bj7SfCRtBDWHUb9snDiAeCFNEtKQo2Wmx5Cou7ajbmo=
 golang.org/x/text v0.0.0-20170915032832-14c0d48ead0c/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=

cmd/pluginator/go.sum

@@ -445,6 +445,7 @@ golang.org/x/sys v0.0.0-20210315160823-c6e025ad8005/go.mod h1:h1NjWce9XRLGQEsW7w
 golang.org/x/sys v0.0.0-20210320140829-1e4c9ba3b0c4/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20210330210617-4fbd30eecc44/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20210403161142-5e06dd20ab57/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/sys v0.0.0-20210510120138-977fb7262007 h1:gG67DSER+11cZvqIMb8S8bt0vZtiN6xWYARwirrOSfE=
 golang.org/x/sys v0.0.0-20210510120138-977fb7262007/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/term v0.0.0-20201126162022-7de9c90e9dd1/go.mod h1:bj7SfCRtBDWHUb9snDiAeCFNEtKQo2Wmx5Cou7ajbmo=
 golang.org/x/text v0.0.0-20170915032832-14c0d48ead0c/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=

kustomize/go.sum

@@ -453,6 +453,7 @@ golang.org/x/sys v0.0.0-20210315160823-c6e025ad8005/go.mod h1:h1NjWce9XRLGQEsW7w
 golang.org/x/sys v0.0.0-20210320140829-1e4c9ba3b0c4/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20210330210617-4fbd30eecc44/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20210403161142-5e06dd20ab57/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/sys v0.0.0-20210510120138-977fb7262007 h1:gG67DSER+11cZvqIMb8S8bt0vZtiN6xWYARwirrOSfE=
 golang.org/x/sys v0.0.0-20210510120138-977fb7262007/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/term v0.0.0-20201126162022-7de9c90e9dd1/go.mod h1:bj7SfCRtBDWHUb9snDiAeCFNEtKQo2Wmx5Cou7ajbmo=
 golang.org/x/text v0.0.0-20170915032832-14c0d48ead0c/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=

kyaml/filesys/filesystem.go

@@ -4,7 +4,10 @@
 package filesys
 
 import (
+	"fmt"
 	"path/filepath"
+
+	"sigs.k8s.io/kustomize/kyaml/errors"
 )
 
 const (
@@ -16,40 +19,70 @@ const (
 // FileSystem groups basic os filesystem methods.
 // It's supposed be functional subset of https://golang.org/pkg/os
 type FileSystem interface {
+
 	// Create a file.
 	Create(path string) (File, error)
+
 	// MkDir makes a directory.
 	Mkdir(path string) error
+
 	// MkDirAll makes a directory path, creating intervening directories.
 	MkdirAll(path string) error
+
 	// RemoveAll removes path and any children it contains.
 	RemoveAll(path string) error
+
 	// Open opens the named file for reading.
 	Open(path string) (File, error)
+
 	// IsDir returns true if the path is a directory.
 	IsDir(path string) bool
+
 	// ReadDir returns a list of files and directories within a directory.
 	ReadDir(path string) ([]string, error)
+
 	// CleanedAbs converts the given path into a
 	// directory and a file name, where the directory
 	// is represented as a ConfirmedDir and all that implies.
 	// If the entire path is a directory, the file component
 	// is an empty string.
 	CleanedAbs(path string) (ConfirmedDir, string, error)
+
 	// Exists is true if the path exists in the file system.
 	Exists(path string) bool
+
 	// Glob returns the list of matching files,
 	// emulating https://golang.org/pkg/path/filepath/#Glob
 	Glob(pattern string) ([]string, error)
+
 	// ReadFile returns the contents of the file at the given path.
 	ReadFile(path string) ([]byte, error)
+
 	// WriteFile writes the data to a file at the given path,
 	// overwriting anything that's already there.
 	WriteFile(path string, data []byte) error
+
 	// Walk walks the file system with the given WalkFunc.
 	Walk(path string, walkFn filepath.WalkFunc) error
 }
 
+// ConfirmDir returns an error if the user-specified path is not an existing directory on fSys.
+// Otherwise, ConfirmDir returns path, which can be relative, as a ConfirmedDir and all that implies.
+func ConfirmDir(fSys FileSystem, path string) (ConfirmedDir, error) {
+	if path == "" {
+		return "", errors.Errorf("directory path cannot be empty")
+	}
+
+	d, f, err := fSys.CleanedAbs(path)
+	if err != nil {
+		return "", errors.WrapPrefixf(err, "not a valid directory")
+	}
+	if f != "" {
+		return "", errors.WrapPrefixf(errors.Errorf("file is not directory"), fmt.Sprintf("'%s'", path))
+	}
+	return d, nil
+}
+
 // FileSystemOrOnDisk satisfies the FileSystem interface by forwarding
 // all of its method calls to the given FileSystem whenever it's not nil.
 // If it's nil, the call is forwarded to the OS's underlying file system.