new(tools/docgen): tool to generate MD documentation

Signed-off-by: Leonardo Di Donato <leodidonato@gmail.com>

tools/docgen/docgen.go

@@ -0,0 +1,81 @@
+package main
+
+import (
+	"flag"
+	"fmt"
+	"os"
+	"path"
+	"strings"
+
+	"github.com/falcosecurity/event-generator/cmd"
+	logger "github.com/sirupsen/logrus"
+	"github.com/spf13/cobra/doc"
+)
+
+const outputDir = "docs"
+const websiteTemplate = `---
+title: %s
+weight: %d
+---
+
+`
+
+var (
+	targetWebsite    bool
+	websitePrepender = func(num int) func(filename string) string {
+		total := num
+		return func(filename string) string {
+			num = num - 1
+			title := strings.TrimPrefix(strings.TrimSuffix(strings.ReplaceAll(filename, "_", " "), ".md"), fmt.Sprintf("%s/", outputDir))
+			return fmt.Sprintf(websiteTemplate, title, total-num)
+		}
+	}
+	websiteLinker = func(filename string) string {
+		if filename == "event-generator.md" {
+			return "_index.md"
+		}
+		return filename
+	}
+)
+
+// docgen
+func main() {
+	// Get mode
+	flag.BoolVar(&targetWebsite, "website", targetWebsite, "")
+	flag.Parse()
+
+	// Get root command
+	evtgen := cmd.New(nil)
+	num := len(evtgen.Commands()) + 1
+
+	// Setup prepender hook
+	prepender := func(num int) func(filename string) string {
+		return func(filename string) string {
+			return ""
+		}
+	}
+	if targetWebsite {
+		prepender = websitePrepender
+	}
+
+	// Setup links hook
+	linker := func(filename string) string {
+		return filename
+	}
+	if targetWebsite {
+		linker = websiteLinker
+	}
+
+	// Generate markdown docs
+	err := doc.GenMarkdownTreeCustom(evtgen, outputDir, prepender(num), linker)
+	if err != nil {
+		logger.WithError(err).Fatal("docs generation")
+	}
+
+	if targetWebsite {
+		err := os.Rename(path.Join(outputDir, "event-generator.md"), path.Join(outputDir, "_index.md"))
+		if err != nil {
+			logger.WithError(err).Fatal("renaming main docs page")
+		}
+	}
+}