kyaml: initial support for yaml and resource manipulation

kyaml/yaml/filters.go

@@ -0,0 +1,140 @@
+// Copyright 2019 The Kubernetes Authors.
+// SPDX-License-Identifier: Apache-2.0
+
+package yaml
+
+import (
+	"fmt"
+	"regexp"
+	"sort"
+	"strings"
+)
+
+var Filters = map[string]func() Filter{
+	"AnnotationClearer": func() Filter { return &AnnotationClearer{} },
+	"AnnotationGetter":  func() Filter { return &AnnotationGetter{} },
+	"AnnotationSetter":  func() Filter { return &AnnotationSetter{} },
+	"ElementAppender":   func() Filter { return &ElementAppender{} },
+	"ElementMatcher":    func() Filter { return &ElementMatcher{} },
+	"FieldClearer":      func() Filter { return &FieldClearer{} },
+	"FilterMatcher":     func() Filter { return &FilterMatcher{} },
+	"FieldMatcher":      func() Filter { return &FieldMatcher{} },
+	"FieldSetter":       func() Filter { return &FieldSetter{} },
+	"PathGetter":        func() Filter { return &PathGetter{} },
+	"PathMatcher":       func() Filter { return &PathMatcher{} },
+	"Parser":            func() Filter { return &Parser{} },
+	"PrefixSetter":      func() Filter { return &PrefixSetter{} },
+	"ValueReplacer":     func() Filter { return &ValueReplacer{} },
+	"SuffixSetter":      func() Filter { return &SuffixSetter{} },
+	"TeePiper":          func() Filter { return &TeePiper{} },
+}
+
+// YFilter wraps the GrepFilter interface so it can be unmarshalled into a struct.
+type YFilter struct {
+	Filter
+}
+
+func (y YFilter) MarshalYAML() (interface{}, error) {
+	return y.Filter, nil
+}
+
+func (y *YFilter) UnmarshalYAML(unmarshal func(interface{}) error) error {
+	meta := &ResourceMeta{}
+	if err := unmarshal(meta); err != nil {
+		return err
+	}
+	if filter, found := Filters[meta.Kind]; !found {
+		var knownFilters []string
+		for k := range Filters {
+			knownFilters = append(knownFilters, k)
+		}
+		sort.Strings(knownFilters)
+		return fmt.Errorf("unsupported GrepFilter Kind %s:  may be one of: [%s]",
+			meta.Kind, strings.Join(knownFilters, ","))
+	} else {
+		y.Filter = filter()
+	}
+	if err := unmarshal(y.Filter); err != nil {
+		return err
+	}
+	return nil
+}
+
+type YFilters []YFilter
+
+func (y YFilters) Filters() []Filter {
+	var f []Filter
+	for i := range y {
+		f = append(f, y[i].Filter)
+	}
+	return f
+}
+
+type FilterMatcher struct {
+	Kind string `yaml:"kind"`
+
+	// Filters are the set of Filters run by TeePiper.
+	Filters YFilters `yaml:"pipeline,omitempty"`
+}
+
+func (t FilterMatcher) Filter(rn *RNode) (*RNode, error) {
+	v, err := rn.Pipe(t.Filters.Filters()...)
+	if v == nil || err != nil {
+		return nil, err
+	}
+	// return the original input if the pipeline resolves to true
+	return rn, err
+}
+
+type ValueReplacer struct {
+	Kind string `yaml:"kind"`
+
+	StringMatch string `yaml:"stringMatch"`
+	RegexMatch  string `yaml:"regexMatch"`
+	Replace     string `yaml:"replace"`
+	Count       int    `yaml:"count"`
+}
+
+func (s ValueReplacer) Filter(object *RNode) (*RNode, error) {
+	if s.Count == 0 {
+		s.Count = -1
+	}
+	if s.StringMatch != "" {
+		object.value.Value = strings.Replace(object.value.Value, s.StringMatch, s.Replace, s.Count)
+	} else if s.RegexMatch != "" {
+		r, err := regexp.Compile(s.RegexMatch)
+		if err != nil {
+			return nil, fmt.Errorf("ValueReplacer RegexMatch does not compile: %v", err)
+		}
+		object.value.Value = r.ReplaceAllString(object.value.Value, s.Replace)
+	} else {
+		return nil, fmt.Errorf("ValueReplacer missing StringMatch and RegexMatch")
+	}
+	return object, nil
+}
+
+type PrefixSetter struct {
+	Kind string `yaml:"kind"`
+
+	Value string `yaml:"value"`
+}
+
+func (s PrefixSetter) Filter(object *RNode) (*RNode, error) {
+	if !strings.HasPrefix(object.value.Value, s.Value) {
+		object.value.Value = s.Value + object.value.Value
+	}
+	return object, nil
+}
+
+type SuffixSetter struct {
+	Kind string `yaml:"kind"`
+
+	Value string `yaml:"value"`
+}
+
+func (s SuffixSetter) Filter(object *RNode) (*RNode, error) {
+	if !strings.HasSuffix(object.value.Value, s.Value) {
+		object.value.Value = object.value.Value + s.Value
+	}
+	return object, nil
+}