Added code for fields with dots(.) in their names work as needed (#4591)

* Added code for fields with dots(.) in their names work as needed

Co-authored-by: sarjamil <sjamil@salesforce.com>

* Fixed imports

Co-authored-by: sarjamil <sjamil@salesforce.com>

* Removed comments

Co-authored-by: sarjamil <sjamil@salesforce.com>

* Fix filter method

Co-authored-by: sarjamil <sjamil@salesforce.com>

* Fixed failing tests

Co-authored-by: sarjamil <sjamil@salesforce.com>

* Remove comments

Add co-author to PR.

Co-authored-by: sarjamil <sjamil@salesforce.com>

* Add co-author to PR.

Co-authored-by: sarjamil sjamil@salesforce.com

Co-authored-by: sarjamil <sjamil@salesforce.com>

kyaml/utils/pathsplitter.go

@@ -0,0 +1,64 @@
+// Copyright 2021 The Kubernetes Authors.
+// SPDX-License-Identifier: Apache-2.0
+
+package utils
+
+import "strings"
+
+// TODO: Move these to kyaml
+
+// PathSplitter splits a delimited string, permitting escaped delimiters.
+func PathSplitter(path string, delimiter string) []string {
+	ps := strings.Split(path, delimiter)
+	var res []string
+	res = append(res, ps[0])
+	for i := 1; i < len(ps); i++ {
+		last := len(res) - 1
+		if strings.HasSuffix(res[last], `\`) {
+			res[last] = strings.TrimSuffix(res[last], `\`) + delimiter + ps[i]
+		} else {
+			res = append(res, ps[i])
+		}
+	}
+	return res
+}
+
+// SmarterPathSplitter splits a path, retaining bracketed elements.
+// If the element is a list entry identifier (defined by the '='),
+// it will retain the brackets.
+// E.g. "[name=com.foo.someapp]" survives as one thing after splitting
+// "spec.template.spec.containers.[name=com.foo.someapp].image"
+// See kyaml/yaml/match.go for use of list entry identifiers.
+// If the element is a mapping entry identifier, it will remove the
+// brackets.
+// E.g. "a.b.c" survives as one thing after splitting
+// "metadata.annotations.[a.b.c]
+// This function uses `PathSplitter`, so it also respects escaped delimiters.
+func SmarterPathSplitter(path string, delimiter string) []string {
+	var result []string
+	split := PathSplitter(path, delimiter)
+
+	for i := 0; i < len(split); i++ {
+		elem := split[i]
+		if strings.HasPrefix(elem, "[") && !strings.HasSuffix(elem, "]") {
+			// continue until we find the matching "]"
+			bracketed := []string{elem}
+			for i < len(split)-1 {
+				i++
+				bracketed = append(bracketed, split[i])
+				if strings.HasSuffix(split[i], "]") {
+					break
+				}
+			}
+			bracketedStr := strings.Join(bracketed, delimiter)
+			if strings.Contains(bracketedStr, "=") {
+				result = append(result, bracketedStr)
+			} else {
+				result = append(result, strings.Trim(bracketedStr, "[]"))
+			}
+		} else {
+			result = append(result, elem)
+		}
+	}
+	return result
+}

kyaml/utils/pathsplitter_test.go

@@ -0,0 +1,94 @@
+// Copyright 2021 The Kubernetes Authors.
+// SPDX-License-Identifier: Apache-2.0
+
+package utils_test
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	. "sigs.k8s.io/kustomize/kyaml/utils"
+)
+
+func TestPathSplitter(t *testing.T) {
+	for _, tc := range []struct {
+		exp  []string
+		path string
+	}{
+		{
+			path: "",
+			exp:  []string{""},
+		},
+		{
+			path: "s",
+			exp:  []string{"s"},
+		},
+		{
+			path: "a/b/c",
+			exp:  []string{"a", "b", "c"},
+		},
+		{
+			path: `a/b[]/c`,
+			exp:  []string{"a", "b[]", "c"},
+		},
+		{
+			path: `a/b\/c/d\/e/f`,
+			exp:  []string{"a", "b/c", "d/e", "f"},
+		},
+		{
+			// The actual reason for this.
+			path: `metadata/annotations/nginx.ingress.kubernetes.io\/auth-secret`,
+			exp: []string{
+				"metadata",
+				"annotations",
+				"nginx.ingress.kubernetes.io/auth-secret"},
+		},
+	} {
+		assert.Equal(t, tc.exp, PathSplitter(tc.path, "/"))
+	}
+}
+
+func TestSmarterPathSplitter(t *testing.T) {
+	testCases := map[string]struct {
+		input    string
+		expected []string
+	}{
+		"simple": {
+			input:    "spec.replicas",
+			expected: []string{"spec", "replicas"},
+		},
+		"sequence": {
+			input:    "spec.data.[name=first].key",
+			expected: []string{"spec", "data", "[name=first]", "key"},
+		},
+		"key, value with . prefix": {
+			input:    "spec.data.[.name=.first].key",
+			expected: []string{"spec", "data", "[.name=.first]", "key"},
+		},
+		"key, value with . suffix": {
+			input:    "spec.data.[name.=first.].key",
+			expected: []string{"spec", "data", "[name.=first.]", "key"},
+		},
+		"multiple '.' in value": {
+			input:    "spec.data.[name=f.i.r.s.t.].key",
+			expected: []string{"spec", "data", "[name=f.i.r.s.t.]", "key"},
+		},
+		"with escaped delimiter": {
+			input:    `spec\.replicas`,
+			expected: []string{`spec.replicas`},
+		},
+		"unmatched bracket": {
+			input:    "spec.data.[name=f.i.[r.s.t..key",
+			expected: []string{"spec", "data", "[name=f.i.[r.s.t..key"},
+		},
+		"mapping value with .": {
+			input:    "metadata.annotations.[a.b.c/d.e.f-g.]",
+			expected: []string{"metadata", "annotations", "a.b.c/d.e.f-g."},
+		},
+	}
+	for tn, tc := range testCases {
+		t.Run(tn, func(t *testing.T) {
+			assert.Equal(t, tc.expected, SmarterPathSplitter(tc.input, "."))
+		})
+	}
+}

kyaml/yaml/rnode.go

@@ -15,6 +15,7 @@ import (
 	"sigs.k8s.io/kustomize/kyaml/errors"
 	"sigs.k8s.io/kustomize/kyaml/internal/forked/github.com/go-yaml/yaml"
 	"sigs.k8s.io/kustomize/kyaml/sliceutil"
+	"sigs.k8s.io/kustomize/kyaml/utils"
 	"sigs.k8s.io/kustomize/kyaml/yaml/internal/k8sgen/pkg/labels"
 )
 
@@ -1207,7 +1208,7 @@ func (rn *RNode) GetString(path string) (string, error) {
 // assuming we keep the var feature in kustomize.
 // The other end of this is: refvar.go:updateNodeValue.
 func (rn *RNode) GetFieldValue(path string) (interface{}, error) {
-	fields := convertSliceIndex(strings.Split(path, "."))
+	fields := convertSliceIndex(utils.SmarterPathSplitter(path, "."))
 	rn, err := rn.Pipe(Lookup(fields...))
 	if err != nil {
 		return nil, err

kyaml/yaml/rnode_test.go

@@ -2310,8 +2310,6 @@ func TestGetAnnotations(t *testing.T) {
 }
 
 func TestGetFieldValueWithDot(t *testing.T) {
-	t.Skip()
-
 	const input = `
 kind: Pod
 metadata:
@@ -2330,8 +2328,6 @@ metadata:
 	require.NoError(t, err)
 	require.Equal(t, "hello-world-app", app)
 
-	// TODO: doesn't currently work; we expect to be able to escape the dot in future
-	// https://github.com/kubernetes-sigs/kustomize/issues/4487
 	fooAppName, err := labelRNode.GetFieldValue(`foo\.appname`)
 	require.NoError(t, err)
 	require.Equal(t, "hello-world-foo", fooAppName) // no field named 'foo.appname'