refactor: add some more useful templating funcs (#4891)

docs/content/en/reference/guides/templating.md

@@ -78,6 +78,9 @@ The following functions which mimic the behaviour of helm exist in most templati
 - kindIs
 - default
 - empty
+- indent
+- nindent
+- uuidv4
 
 See the [Helm Documentation](https://helm.sh/docs/chart_template_guide/function_list/) for more information. Please
 note that only the functions listed above are supported and the functions don't necessarily behave exactly the same.
@@ -92,3 +95,7 @@ The following is a list of special functions and their syntax.
 #### iterate
 
 Input is a single uint. Returns a slice of uints from 0 to the provided uint.
+
+#### fileContent
+
+Input is a path. Returns the content of a file.

internal/templates/funcs.go

@@ -17,62 +17,68 @@ import (
 	"strconv"
 	"strings"
 	"time"
+
+	"github.com/google/uuid"
 )
 
 // FuncMap returns the template FuncMap commonly used in several templates.
 func FuncMap() map[string]any {
 	return map[string]any{
-		"iterate":    FuncIterate,
+		"iterate":     FuncIterate,
-		"env":        FuncGetEnv,
+		"fileContent": FuncFileContent,
-		"expandenv":  FuncExpandEnv,
+		"env":         FuncGetEnv,
-		"split":      FuncStringSplit,
+		"expandenv":   FuncExpandEnv,
-		"splitList":  FuncStringSplitList,
+		"split":       FuncStringSplit,
-		"join":       FuncElemsJoin,
+		"splitList":   FuncStringSplitList,
-		"contains":   FuncStringContains,
+		"join":        FuncElemsJoin,
-		"hasPrefix":  FuncStringHasPrefix,
+		"contains":    FuncStringContains,
-		"hasSuffix":  FuncStringHasSuffix,
+		"hasPrefix":   FuncStringHasPrefix,
-		"lower":      strings.ToLower,
+		"hasSuffix":   FuncStringHasSuffix,
-		"keys":       FuncKeys,
+		"lower":       strings.ToLower,
-		"sortAlpha":  FuncSortAlpha,
+		"keys":        FuncKeys,
-		"upper":      strings.ToUpper,
+		"sortAlpha":   FuncSortAlpha,
-		"title":      strings.ToTitle,
+		"upper":       strings.ToUpper,
-		"trim":       strings.TrimSpace,
+		"title":       strings.ToTitle,
-		"trimAll":    FuncStringTrimAll,
+		"trim":        strings.TrimSpace,
-		"trimSuffix": FuncStringTrimSuffix,
+		"trimAll":     FuncStringTrimAll,
-		"trimPrefix": FuncStringTrimPrefix,
+		"trimSuffix":  FuncStringTrimSuffix,
-		"replace":    FuncStringReplace,
+		"trimPrefix":  FuncStringTrimPrefix,
-		"quote":      FuncStringQuote,
+		"replace":     FuncStringReplace,
-		"sha1sum":    FuncHashSum(sha1.New),
+		"quote":       FuncStringQuote,
-		"sha256sum":  FuncHashSum(sha256.New),
+		"sha1sum":     FuncHashSum(sha1.New),
-		"sha512sum":  FuncHashSum(sha512.New),
+		"sha256sum":   FuncHashSum(sha256.New),
-		"squote":     FuncStringSQuote,
+		"sha512sum":   FuncHashSum(sha512.New),
-		"now":        time.Now,
+		"squote":      FuncStringSQuote,
-		"b64enc":     FuncB64Enc,
+		"now":         time.Now,
-		"b64dec":     FuncB64Dec,
+		"b64enc":      FuncB64Enc,
-		"b32enc":     FuncB32Enc,
+		"b64dec":      FuncB64Dec,
-		"b32dec":     FuncB32Dec,
+		"b32enc":      FuncB32Enc,
-		"list":       FuncList,
+		"b32dec":      FuncB32Dec,
-		"dict":       FuncDict,
+		"list":        FuncList,
-		"get":        FuncGet,
+		"dict":        FuncDict,
-		"set":        FuncSet,
+		"get":         FuncGet,
-		"isAbs":      path.IsAbs,
+		"set":         FuncSet,
-		"base":       path.Base,
+		"isAbs":       path.IsAbs,
-		"dir":        path.Dir,
+		"base":        path.Base,
-		"ext":        path.Ext,
+		"dir":         path.Dir,
-		"clean":      path.Clean,
+		"ext":         path.Ext,
-		"osBase":     filepath.Base,
+		"clean":       path.Clean,
-		"osClean":    filepath.Clean,
+		"osBase":      filepath.Base,
-		"osDir":      filepath.Dir,
+		"osClean":     filepath.Clean,
-		"osExt":      filepath.Ext,
+		"osDir":       filepath.Dir,
-		"osIsAbs":    filepath.IsAbs,
+		"osExt":       filepath.Ext,
-		"deepEqual":  reflect.DeepEqual,
+		"osIsAbs":     filepath.IsAbs,
-		"typeOf":     FuncTypeOf,
+		"deepEqual":   reflect.DeepEqual,
-		"typeIs":     FuncTypeIs,
+		"typeOf":      FuncTypeOf,
-		"typeIsLike": FuncTypeIsLike,
+		"typeIs":      FuncTypeIs,
-		"kindOf":     FuncKindOf,
+		"typeIsLike":  FuncTypeIsLike,
-		"kindIs":     FuncKindIs,
+		"kindOf":      FuncKindOf,
-		"default":    FuncDefault,
+		"kindIs":      FuncKindIs,
-		"empty":      FuncEmpty,
+		"default":     FuncDefault,
+		"empty":       FuncEmpty,
+		"indent":      FuncIndent,
+		"nindent":     FuncNewlineIndent,
+		"uuidv4":      FuncUUIDv4,
 	}
 }
 
@@ -384,3 +390,31 @@ func FuncEmpty(v any) bool {
 		return false
 	}
 }
+
+// FuncIndent is a helper function that provides similar functionality to the helm indent func.
+func FuncIndent(indent int, value string) string {
+	padding := strings.Repeat(" ", indent)
+
+	return padding + strings.ReplaceAll(value, "\n", "\n"+padding)
+}
+
+// FuncNewlineIndent is a helper function that provides similar functionality to the helm nindent func.
+func FuncNewlineIndent(indent int, value string) string {
+	return "\n" + FuncIndent(indent, value)
+}
+
+// FuncUUIDv4 is a helper function that provides similar functionality to the helm uuidv4 func.
+func FuncUUIDv4() string {
+	return uuid.New().String()
+}
+
+// FuncFileContent returns the file content.
+func FuncFileContent(path string) (data string, err error) {
+	var raw []byte
+
+	if raw, err = os.ReadFile(path); err != nil {
+		return "", err
+	}
+
+	return string(raw), nil
+}

internal/templates/funcs_test.go

@@ -638,3 +638,23 @@ func TestFuncEmpty(t *testing.T) {
 		})
 	}
 }
+
+func TestFuncIndent(t *testing.T) {
+	testCases := []struct {
+		name     string
+		have     string
+		indent   int
+		expected []string
+	}{
+		{"ShouldIndentZeroMultiLine", "abc\n123", 0, []string{"abc\n123", "\nabc\n123"}},
+		{"ShouldIndentOneMultiLine", "abc\n123", 1, []string{" abc\n 123", "\n abc\n 123"}},
+		{"ShouldIndentOneSingleLine", "abc", 1, []string{" abc", "\n abc"}},
+		{"ShouldIndentZeroSingleLine", "abc", 0, []string{"abc", "\nabc"}},
+	}
+
+	for _, tc := range testCases {
+		for i, f := range []func(i int, v string) string{FuncIndent, FuncNewlineIndent} {
+			assert.Equal(t, tc.expected[i], f(tc.indent, tc.have))
+		}
+	}
+}