Files
kustomize/kyaml/fn/framework/parser/template.go
2022-04-21 18:28:13 -04:00

104 lines
2.9 KiB
Go

// Copyright 2021 The Kubernetes Authors.
// SPDX-License-Identifier: Apache-2.0
package parser
import (
"fmt"
iofs "io/fs"
"os"
"path/filepath"
"text/template"
"sigs.k8s.io/kustomize/kyaml/fn/framework"
)
const (
// TemplateExtension is the file extension this package requires template files to have
TemplateExtension = ".template.yaml"
)
// TemplateStrings returns a TemplateParser that will parse the templates from the given strings.
//
// This is a helper for use with framework.TemplateProcessor's template subfields. Example:
//
// processor := framework.TemplateProcessor{
// ResourceTemplates: []framework.ResourceTemplate{{
// Templates: parser.TemplateStrings(`
// apiVersion: apps/v1
// kind: Deployment
// metadata:
// name: foo
// namespace: default
// annotations:
// {{ .Key }}: {{ .Value }}
// `)
// }},
// }
func TemplateStrings(data ...string) framework.TemplateParser {
return framework.TemplateParserFunc(func() ([]*template.Template, error) {
var templates []*template.Template
for i := range data {
t, err := template.New(fmt.Sprintf("inline%d", i)).Parse(data[i])
if err != nil {
return nil, err
}
templates = append(templates, t)
}
return templates, nil
})
}
// TemplateFiles returns a TemplateParser that will parse the templates from the given files or directories.
// Only immediate children of any given directories will be parsed.
// All files must end in .template.yaml.
//
// This is a helper for use with framework.TemplateProcessor's template subfields. Example:
//
// processor := framework.TemplateProcessor{
// ResourceTemplates: []framework.ResourceTemplate{{
// Templates: parser.TemplateFiles("path/to/templates", "path/to/special.template.yaml")
// }},
// }
func TemplateFiles(paths ...string) TemplateParser {
return TemplateParser{parser{paths: paths, extensions: []string{TemplateExtension}}}
}
// TemplateParser is a framework.TemplateParser that can parse files or directories containing Go templated YAML.
type TemplateParser struct {
parser
}
// Parse implements framework.TemplateParser
func (l TemplateParser) Parse() ([]*template.Template, error) {
if l.fs == nil {
l.fs = os.DirFS(".")
}
var templates []*template.Template
err := l.parse(func(content []byte, file string) error {
t, err := template.New(filepath.Base(file)).Parse(string(content))
if err == nil {
templates = append(templates, t)
}
return err
})
if err != nil {
return nil, err
}
return templates, nil
}
// FromFS allows you to replace the filesystem in which the parser will look up the given paths.
// For example, you can use an embed.FS.
func (l TemplateParser) FromFS(fs iofs.FS) TemplateParser {
l.parser.fs = fs
return l
}
// WithExtensions allows you to replace the extension the parser accept on the input files.
func (l TemplateParser) WithExtensions(ext ...string) TemplateParser {
l.parser.extensions = ext
return l
}