pathsplitter.go

Documentation: sigs.k8s.io/kustomize/kyaml/utils

     1  // Copyright 2021 The Kubernetes Authors.
     2  // SPDX-License-Identifier: Apache-2.0
     3  
     4  package utils
     5  
     6  import "strings"
     7  
     8  // TODO: Move these to kyaml
     9  
    10  // PathSplitter splits a delimited string, permitting escaped delimiters.
    11  func PathSplitter(path string, delimiter string) []string {
    12  	ps := strings.Split(path, delimiter)
    13  	var res []string
    14  
    15  	// allow path to start with forward slash
    16  	// i.e. /a/b/c
    17  	if len(ps) > 1 && ps[0] == "" {
    18  		ps = ps[1:]
    19  	}
    20  
    21  	res = append(res, ps[0])
    22  	for i := 1; i < len(ps); i++ {
    23  		last := len(res) - 1
    24  		if strings.HasSuffix(res[last], `\`) {
    25  			res[last] = strings.TrimSuffix(res[last], `\`) + delimiter + ps[i]
    26  		} else {
    27  			res = append(res, ps[i])
    28  		}
    29  	}
    30  	return res
    31  }
    32  
    33  // SmarterPathSplitter splits a path, retaining bracketed elements.
    34  // If the element is a list entry identifier (defined by the '='),
    35  // it will retain the brackets.
    36  // E.g. "[name=com.foo.someapp]" survives as one thing after splitting
    37  // "spec.template.spec.containers.[name=com.foo.someapp].image"
    38  // See kyaml/yaml/match.go for use of list entry identifiers.
    39  // If the element is a mapping entry identifier, it will remove the
    40  // brackets.
    41  // E.g. "a.b.c" survives as one thing after splitting
    42  // "metadata.annotations.[a.b.c]
    43  // This function uses `PathSplitter`, so it also respects escaped delimiters.
    44  func SmarterPathSplitter(path string, delimiter string) []string {
    45  	var result []string
    46  	split := PathSplitter(path, delimiter)
    47  
    48  	for i := 0; i < len(split); i++ {
    49  		elem := split[i]
    50  		if strings.HasPrefix(elem, "[") && !strings.HasSuffix(elem, "]") {
    51  			// continue until we find the matching "]"
    52  			bracketed := []string{elem}
    53  			for i < len(split)-1 {
    54  				i++
    55  				bracketed = append(bracketed, split[i])
    56  				if strings.HasSuffix(split[i], "]") {
    57  					break
    58  				}
    59  			}
    60  			bracketedStr := strings.Join(bracketed, delimiter)
    61  			if strings.Contains(bracketedStr, "=") {
    62  				result = append(result, bracketedStr)
    63  			} else {
    64  				result = append(result, strings.Trim(bracketedStr, "[]"))
    65  			}
    66  		} else {
    67  			result = append(result, elem)
    68  		}
    69  	}
    70  	return result
    71  }
    72
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