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tailscale/cmd/k8s-operator/generate/main.go

140 lines
4.2 KiB
Go

// Copyright (c) Tailscale Inc & AUTHORS
// SPDX-License-Identifier: BSD-3-Clause
//go:build !plan9
package main
import (
"bytes"
"fmt"
"io"
"log"
"os"
"os/exec"
"path/filepath"
"strings"
"gopkg.in/yaml.v3"
)
const (
operatorDeploymentFilesPath = "cmd/k8s-operator/deploy"
crdPath = operatorDeploymentFilesPath + "/crds/tailscale.com_connectors.yaml"
helmTemplatesPath = operatorDeploymentFilesPath + "/chart/templates"
crdTemplatePath = helmTemplatesPath + "/connectors.yaml"
helmConditionalStart = "{{ if .Values.installCRDs -}}\n"
helmConditionalEnd = "{{- end -}}"
)
func main() {
if len(os.Args) < 2 {
log.Fatalf("usage ./generate [staticmanifests|helmcrd]")
}
repoRoot := "../../"
switch os.Args[1] {
case "helmcrd": // insert CRD to Helm templates behind a installCRDs=true conditional check
log.Print("Adding Connector CRD to Helm templates")
if err := generate("./"); err != nil {
log.Fatalf("error adding Connector CRD to Helm templates: %v", err)
}
return
case "staticmanifests": // generate static manifests from Helm templates (including the CRD)
default:
log.Fatalf("unknown option %s, known options are 'staticmanifests', 'helmcrd'", os.Args[1])
}
log.Printf("Inserting CRD into the Helm templates")
if err := generate(repoRoot); err != nil {
log.Fatalf("error adding Connector CRD to Helm templates: %v", err)
}
defer func() {
if err := cleanup(repoRoot); err != nil {
log.Fatalf("error cleaning up generated resources")
}
}()
log.Print("Templating Helm chart contents")
helmTmplCmd := exec.Command("./tool/helm", "template", "operator", "./cmd/k8s-operator/deploy/chart",
"--namespace=tailscale")
helmTmplCmd.Dir = repoRoot
var out bytes.Buffer
helmTmplCmd.Stdout = &out
helmTmplCmd.Stderr = os.Stderr
if err := helmTmplCmd.Run(); err != nil {
log.Fatalf("error templating helm manifests: %v", err)
}
var final bytes.Buffer
templatePath := filepath.Join(repoRoot, "cmd/k8s-operator/deploy/manifests/templates")
fileInfos, err := os.ReadDir(templatePath)
if err != nil {
log.Fatalf("error reading templates: %v", err)
}
for _, fi := range fileInfos {
templateBytes, err := os.ReadFile(filepath.Join(templatePath, fi.Name()))
if err != nil {
log.Fatalf("error reading template: %v", err)
}
final.Write(templateBytes)
}
decoder := yaml.NewDecoder(&out)
for {
var document any
err := decoder.Decode(&document)
if err == io.EOF {
break
}
if err != nil {
log.Fatalf("failed read from input data: %v", err)
}
bytes, err := yaml.Marshal(document)
if err != nil {
log.Fatalf("failed to marshal YAML document: %v", err)
}
if strings.TrimSpace(string(bytes)) == "null" {
continue
}
if _, err = final.Write(bytes); err != nil {
log.Fatalf("error marshaling yaml: %v", err)
}
fmt.Fprint(&final, "---\n")
}
finalString, _ := strings.CutSuffix(final.String(), "---\n")
if err := os.WriteFile(filepath.Join(repoRoot, "cmd/k8s-operator/deploy/manifests/operator.yaml"), []byte(finalString), 0664); err != nil {
log.Fatalf("error writing new file: %v", err)
}
}
func generate(baseDir string) error {
log.Print("Placing Connector CRD into Helm templates..")
chartBytes, err := os.ReadFile(filepath.Join(baseDir, crdPath))
if err != nil {
return fmt.Errorf("error reading CRD contents: %w", err)
}
// Place a new temporary Helm template file with the templated CRD
// contents into Helm templates.
file, err := os.Create(filepath.Join(baseDir, crdTemplatePath))
if err != nil {
return fmt.Errorf("error creating CRD template file: %w", err)
}
if _, err := file.Write([]byte(helmConditionalStart)); err != nil {
return fmt.Errorf("error writing helm if statement start: %w", err)
}
if _, err := file.Write(chartBytes); err != nil {
return fmt.Errorf("error writing chart bytes: %w", err)
}
if _, err := file.Write([]byte(helmConditionalEnd)); err != nil {
return fmt.Errorf("error writing helm if-statement end: %w", err)
}
return nil
}
func cleanup(baseDir string) error {
log.Print("Cleaning up CRD from Helm templates")
if err := os.Remove(filepath.Join(baseDir, crdTemplatePath)); err != nil && !os.IsNotExist(err) {
return fmt.Errorf("error cleaning up CRD template: %w", err)
}
return nil
}