script/generator/generator.go

package main

import (
	"fmt"
	"io/ioutil"
	"os"
	"path/filepath"
	"sort"
	"strings"

	camel "github.com/apache/camel-k/pkg/apis/camel/v1alpha1"
	"k8s.io/apimachinery/pkg/runtime"
	"k8s.io/apimachinery/pkg/runtime/schema"
	"k8s.io/apimachinery/pkg/runtime/serializer"
	"k8s.io/apimachinery/pkg/util/yaml"
)

func main() {
	if len(os.Args) != 3 {
		println("usage: generator kamelets-path doc-root")
		os.Exit(1)
	}

	projectBaseDir := os.Args[1]
	docBaseDir := os.Args[2]

	kamelets := listKamelets(projectBaseDir)

	links := make([]string, 0)
	for _, k := range kamelets {
		links = updateImageLink(k, links)
	}

	saveNav(links, docBaseDir)
}

func updateImageLink(k camel.Kamelet, links []string) []string {
	return append(links, fmt.Sprintf("* xref:%s.adoc[]", k.Name))
}

func saveNav(links []string, out string) {
	content := "// THIS FILE IS AUTOMATICALLY GENERATED: DO NOT EDIT\n"
	for _, l := range links {
		content += l + "\n"
	}
	content += "// THIS FILE IS AUTOMATICALLY GENERATED: DO NOT EDIT\n"
	dest := filepath.Join(out, "nav.adoc")
	if _, err := os.Stat(dest); err == nil {
		err = os.Remove(dest)
		handleGeneralError(fmt.Sprintf("cannot remove file %q", dest), err)
	}
	err := ioutil.WriteFile(dest, []byte(content), 0666)
	handleGeneralError(fmt.Sprintf("cannot write file %q", dest), err)
	fmt.Printf("%q written\n", dest)
}

func listKamelets(dir string) []camel.Kamelet {
	scheme := runtime.NewScheme()
	err := camel.AddToScheme(scheme)
	handleGeneralError("cannot to add camel APIs to scheme", err)

	codecs := serializer.NewCodecFactory(scheme)
	gv := camel.SchemeGroupVersion
	gvk := schema.GroupVersionKind{
		Group:   gv.Group,
		Version: gv.Version,
		Kind:    "Kamelet",
	}
	decoder := codecs.UniversalDecoder(gv)

	kamelets := make([]camel.Kamelet, 0)
	files, err := ioutil.ReadDir(dir)
	filesSorted := make([]string, 0)
	handleGeneralError(fmt.Sprintf("cannot list dir %q", dir), err)
	for _, fd := range files {
		if !fd.IsDir() && strings.HasSuffix(fd.Name(), ".kamelet.yaml") {
			fullName := filepath.Join(dir, fd.Name())
			filesSorted = append(filesSorted, fullName)
		}
	}
	sort.Strings(filesSorted)
	for _, fileName := range filesSorted {
		content, err := ioutil.ReadFile(fileName)
		handleGeneralError(fmt.Sprintf("cannot read file %q", fileName), err)

		json, err := yaml.ToJSON(content)
		handleGeneralError(fmt.Sprintf("cannot convert file %q to JSON", fileName), err)

		kamelet := camel.Kamelet{}
		_, _, err = decoder.Decode(json, &gvk, &kamelet)
		handleGeneralError(fmt.Sprintf("cannot unmarshal file %q into Kamelet", fileName), err)
		kamelets = append(kamelets, kamelet)
	}
	return kamelets
}

func handleGeneralError(desc string, err error) {
	if err != nil {
		fmt.Printf("%s: %+v\n", desc, err)
		os.Exit(2)
	}
}