mirror of
https://github.com/kubernetes-sigs/kustomize.git
synced 2026-06-11 09:02:53 +00:00
5c4b5b1bf0
This commit creates a new version of the alpha configuration functions framework. Goals include: - Make it easy to build multi-version APIs with the framework (not previously facilitated at all). - Simplify the framework's APIs where redundant configuration options exist (leaving the most powerful, replacing others with helpers to maintain usability they provided). - Make the Framework's APIs more consistent (e.g. between the various template types, usage of kio.Filter, field names) - Decouple responsibilities (e.g. command creation, resource list processing, generation of templating functions). - Make the framework even more powerfully pluggable (e.g. any kio.Filter can be a selector, and the selector the framework provides is itself a filter built from reusable abstractions). - Improve documentation. - Make container patches merge fields (notably list fields like `env`) correctly.
81 lines
2.1 KiB
Go
81 lines
2.1 KiB
Go
// Copyright 2021 The Kubernetes Authors.
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// SPDX-License-Identifier: Apache-2.0
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package framework
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import (
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"bytes"
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"strings"
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"text/template"
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"sigs.k8s.io/kustomize/kyaml/errors"
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"sigs.k8s.io/kustomize/kyaml/kio"
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"sigs.k8s.io/kustomize/kyaml/yaml"
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)
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// ResourceTemplate generates resources from templates.
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type ResourceTemplate struct {
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// Templates is a function that returns a list of templates to render into one or more resources.
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Templates TemplatesFunc
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// TemplateData is the data to use when rendering the templates provided by the Templates field.
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TemplateData interface{}
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}
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// DefaultTemplateData sets TemplateData to the provided default values if it has not already
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// been set.
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func (rt *ResourceTemplate) DefaultTemplateData(data interface{}) {
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if rt.TemplateData == nil {
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rt.TemplateData = data
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}
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}
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// Render renders the Templates into resource nodes using TemplateData.
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func (rt *ResourceTemplate) Render() ([]*yaml.RNode, error) {
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var items []*yaml.RNode
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if rt.Templates == nil {
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return items, nil
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}
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templates, err := rt.Templates()
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if err != nil {
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return nil, errors.WrapPrefixf(err, "failed to retrieve ResourceTemplates")
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}
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for i := range templates {
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newItems, err := rt.doTemplate(templates[i])
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if err != nil {
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return nil, err
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}
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items = append(items, newItems...)
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}
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return items, nil
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}
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func (rt *ResourceTemplate) doTemplate(t *template.Template) ([]*yaml.RNode, error) {
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// invoke the template
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var b bytes.Buffer
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err := t.Execute(&b, rt.TemplateData)
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if err != nil {
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return nil, errors.WrapPrefixf(err, "failed to render template %v", t.DefinedTemplates())
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}
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var items []*yaml.RNode
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// split the resources so the error messaging is better
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for _, s := range strings.Split(b.String(), "\n---\n") {
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s = strings.TrimSpace(s)
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if s == "" {
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continue
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}
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newItems, err := (&kio.ByteReader{Reader: bytes.NewBufferString(s)}).Read()
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if err != nil {
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return nil, errors.WrapPrefixf(err,
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"failed to parse rendered template into a resource:\n%s\n", addLineNumbers(s))
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}
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items = append(items, newItems...)
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}
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return items, nil
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}
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