gitea-webhook-listener/main.go

package main

import (
	"context"
	"encoding/json"
	"fmt"
	"io"
	"log"
	"net/http"
	"os"
	"os/exec"
	"os/signal"
	"path"
	"runtime"
	"strings"
	"syscall"

	"gitea.urkob.com/urko/gitea-webhook-listener/internal"
	"gitea.urkob.com/urko/gitea-webhook-listener/kit/config"
)

func main() {
	var err error
	ctx, cancel := context.WithCancel(signalContext(context.Background()))
	defer cancel()

	cfgFile := os.Getenv("CONFIG_FILE")
	if cfgFile == "" {
		// Get root path
		_, filename, _, _ := runtime.Caller(0)
		cfgFile = path.Join(path.Dir(filename), "configs", "app.yml")
	}
	cfg, err := config.LoadConfig(cfgFile)
	if err != nil {
		log.Fatalf("Error loading config: %v", err)
	}
	http.HandleFunc("/", handlePayload(cfg.Secret, cfg.Projects))

	go func() {
		err = http.ListenAndServe(fmt.Sprintf(":%d", cfg.Port), nil)
	}()
	log.Printf("server is up on %d\n", cfg.Port)

	<-ctx.Done()
	if err != nil {
		log.Println("some error happened", err)
	}
	log.Println("server shutdown")
}

func handlePayload(secret string, projects map[string][]config.ConfigScript) func(w http.ResponseWriter, r *http.Request) {
	return (func(w http.ResponseWriter, r *http.Request) {
		// Read the request body
		body, err := io.ReadAll(r.Body)
		if err != nil {
			http.Error(w, "Failed to read request body", http.StatusBadRequest)
			return
		}
		defer r.Body.Close()

		authHeader := r.Header.Get("Authorization")
		if authHeader != secret {
			http.Error(w, "Signatures didn't match", http.StatusUnauthorized)
			return
		}

		if !r.URL.Query().Has("project") {
			http.Error(w, "", http.StatusBadRequest)
			return
		}

		project := r.URL.Query().Get("project")
		proj, found := projects[project]
		if !found {
			http.Error(w, "not found", http.StatusNotFound)
			log.Printf("project %s not found\n", project)
			return
		}
		var payload internal.WebhookPayload
		if err = json.Unmarshal(body, &payload); err != nil {
			http.Error(w, "Failed to parse JSON payload", http.StatusBadRequest)
			return
		}
		branchName := strings.Split(payload.Ref, "/")[len(strings.Split(payload.Ref, "/"))-1]
		found = false
		var scr config.ConfigScript
		for i := range proj {
			if proj[i].Environment == branchName {
				found = true
				scr = proj[i]
				break
			}

		}
		if !found {
			http.Error(w, "not found", http.StatusNotFound)
			log.Printf("project %s with branch %s not found\n", project, branchName)
			return
		}

		go func() {
			if err := execute(scr.Command, scr.Arguments...); err != nil {
				log.Println(err)
			}
		}()
	})
}

func execute(command string, args ...string) error {
	cmd := exec.Command(command, args...)
	cmd.Stdout = os.Stdout
	cmd.Stderr = os.Stderr

	if err := cmd.Run(); err != nil {
		return fmt.Errorf("cmd.Run %w", err)
	}

	return nil
}

func signalContext(ctx context.Context) context.Context {
	ctx, cancel := context.WithCancel(ctx)

	sigs := make(chan os.Signal, 1)
	signal.Notify(sigs, os.Interrupt, syscall.SIGINT, syscall.SIGTERM)

	go func() {
		<-sigs
		signal.Stop(sigs)
		close(sigs)
		cancel()
	}()

	return ctx
}