Reinstate #4652 without url-related code

Remove code that changes remotes-loading code path, as mandated by #4756

api/loader/fileloader.go

@@ -18,6 +18,13 @@ import (
 	"sigs.k8s.io/kustomize/kyaml/filesys"
 )
 
+// HasRemoteFileScheme returns whether path has a url scheme that kustomize allows for
+// remote files. See https://github.com/kubernetes-sigs/kustomize/blob/master/examples/remoteBuild.md
+func HasRemoteFileScheme(path string) bool {
+	u, err := url.Parse(path)
+	return err == nil && (u.Scheme == "http" || u.Scheme == "https")
+}
+
 // fileLoader is a kustomization's interface to files.
 //
 // The directory in which a kustomization file sits
@@ -114,6 +121,15 @@ func NewFileLoaderAtRoot(fSys filesys.FileSystem) *fileLoader {
 		RestrictionRootOnly, fSys, filesys.Separator)
 }
 
+// Repo returns the absolute path to the repo that contains Root and true
+// if this fileLoader was created from a url; otherwise, the empty string and false
+func (fl *fileLoader) Repo() (string, bool) {
+	if fl.repoSpec != nil {
+		return fl.repoSpec.Dir.String(), true
+	}
+	return "", false
+}
+
 // Root returns the absolute path that is prepended to any
 // relative paths used in Load.
 func (fl *fileLoader) Root() string {
@@ -283,6 +299,7 @@ func (fl *fileLoader) errIfRepoCycle(newRepoSpec *git.RepoSpec) error {
 // else an error. Relative paths are taken relative
 // to the root.
 func (fl *fileLoader) Load(path string) ([]byte, error) {
+	// TODO(annasong): replace check with HasRemoteFileScheme
 	if u, err := url.Parse(path); err == nil && (u.Scheme == "http" || u.Scheme == "https") {
 		var hc *http.Client
 		if fl.http != nil {

api/loader/fileloader_test.go

@@ -21,6 +21,40 @@ import (
 	"sigs.k8s.io/kustomize/kyaml/filesys"
 )
 
+func TestHasRemoteFileScheme(t *testing.T) {
+	cases := map[string]struct {
+		url   string
+		valid bool
+	}{
+		"https file": {
+			"https://raw.githubusercontent.com/kubernetes-sigs/kustomize/master/examples/helloWorld/configMap.yaml",
+			true,
+		},
+		"https dir": {
+			"https://github.com/kubernetes-sigs/kustomize//examples/helloWorld/",
+			true,
+		},
+		"no scheme": {
+			"github.com/kubernetes-sigs/kustomize//examples/helloWorld/",
+			false,
+		},
+		"ssh": {
+			"ssh://git@github.com/kubernetes-sigs/kustomize.git",
+			false,
+		},
+		"local": {
+			"pod.yaml",
+			false,
+		},
+	}
+	for name, test := range cases {
+		test := test
+		t.Run(name, func(t *testing.T) {
+			require.Equal(t, test.valid, HasRemoteFileScheme(test.url))
+		})
+	}
+}
+
 type testData struct {
 	path            string
 	expectedContent string
@@ -61,6 +95,8 @@ func TestLoaderLoad(t *testing.T) {
 	require := require.New(t)
 
 	l1 := makeLoader()
+	_, remote := l1.Repo()
+	require.False(remote)
 	require.Equal("/", l1.Root())
 
 	for _, x := range testCases {
@@ -73,6 +109,9 @@ func TestLoaderLoad(t *testing.T) {
 	}
 	l2, err := l1.New("foo/project")
 	require.NoError(err)
+
+	_, remote = l2.Repo()
+	require.False(remote)
 	require.Equal("/foo/project", l2.Root())
 
 	for _, x := range testCases {
@@ -322,6 +361,9 @@ whatever
 		repoSpec, fSys, nil,
 		git.DoNothingCloner(filesys.ConfirmedDir(coRoot)))
 	require.NoError(err)
+	repo, remote := l.Repo()
+	require.True(remote)
+	require.Equal(coRoot, repo)
 	require.Equal(coRoot+"/"+pathInRepo, l.Root())
 
 	_, err = l.New(url)
@@ -335,6 +377,10 @@ whatever
 	url = rootURL + "/" + pathInRepo
 	l2, err := l.New(url)
 	require.NoError(err)
+
+	repo, remote = l2.Repo()
+	require.True(remote)
+	require.Equal(coRoot, repo)
 	require.Equal(coRoot+"/"+pathInRepo, l2.Root())
 }
 
@@ -389,6 +435,8 @@ func TestLoaderDisallowsLocalBaseFromRemoteOverlay(t *testing.T) {
 	// This is okay.
 	l2, err = l1.New("../base")
 	require.NoError(err)
+	_, remote := l2.Repo()
+	require.False(remote)
 	require.Equal(cloneRoot+"/foo/base", l2.Root())
 
 	// This is not okay.
@@ -414,6 +462,9 @@ func TestLocalLoaderReferencingGitBase(t *testing.T) {
 
 	l2, err := l1.New("github.com/someOrg/someRepo/foo/base")
 	require.NoError(err)
+	repo, remote := l2.Repo()
+	require.True(remote)
+	require.Equal(cloneRoot, repo)
 	require.Equal(cloneRoot+"/foo/base", l2.Root())
 }