Add a configuration file.

src/config.go

@@ -0,0 +1,27 @@
+package main
+
+import (
+	"os"
+
+	"github.com/pelletier/go-toml/v2"
+)
+
+type Config struct {
+	DataDir string `toml:"data-dir"`
+	Listen  struct {
+		Protocol string `toml:"protocol"`
+		Address  string `toml:"address"`
+	} `toml:"listen"`
+}
+
+func readConfig(path string, config *Config) error {
+	file, err := os.Open(path)
+	if err != nil {
+		return err
+	}
+	defer file.Close()
+
+	decoder := toml.NewDecoder(file)
+	decoder.DisallowUnknownFields()
+	return decoder.Decode(config)
+}

src/fetch.go

@@ -37,7 +37,6 @@ func splitHash(hash plumbing.Hash) string {
 }
 
 func fetch(
-	dataDir string,
 	webRoot string,
 	repoURL string,
 	branch string,
@@ -61,10 +60,10 @@ func fetch(
 	}
 	head := ref.Hash()
 
-	destDir := filepath.Join(dataDir, "tree", splitHash(head))
+	destDir := filepath.Join(config.DataDir, "tree", splitHash(head))
 	if _, err := os.Stat(destDir); errors.Is(err, os.ErrNotExist) {
 		// check out to a temporary directory to avoid TOCTTOU race on destDir
-		tempDir, err := os.MkdirTemp(dataDir, ".tree")
+		tempDir, err := os.MkdirTemp(config.DataDir, ".tree")
 		if err != nil {
 			return FetchResult{err: fmt.Errorf("mkdir temp: %s", err)}
 		}
@@ -96,10 +95,10 @@ func fetch(
 		}
 	}
 
-	webLink := filepath.Join(dataDir, "www", webRoot)
+	webLink := filepath.Join(config.DataDir, "www", webRoot)
 	destDirRel, _ := filepath.Rel(filepath.Dir(webLink), destDir)
 
-	tempLink := filepath.Join(dataDir,
+	tempLink := filepath.Join(config.DataDir,
 		fmt.Sprintf(".link.%s.%s", strings.ReplaceAll(webRoot, "/", ".."), head.String()))
 	if err := os.Symlink(destDirRel, tempLink); err != nil {
 		return FetchResult{err: fmt.Errorf("symlink temp: %s", err)}
@@ -131,13 +130,12 @@ func fetch(
 }
 
 func Fetch(
-	dataDir string,
 	webRoot string,
 	repoURL string,
 	branch string,
 ) FetchResult {
 	log.Println("fetch:", webRoot, repoURL, branch)
-	result := fetch(dataDir, webRoot, repoURL, branch)
+	result := fetch(webRoot, repoURL, branch)
 	if result.err == nil {
 		status := ""
 		switch result.outcome {
@@ -156,7 +154,6 @@ func Fetch(
 }
 
 func FetchWithTimeout(
-	dataDir string,
 	webRoot string,
 	repoURL string,
 	branch string,
@@ -165,7 +162,7 @@ func FetchWithTimeout(
 	// fetch the updated content with a timeout
 	c := make(chan FetchResult, 1)
 	go func() {
-		result := Fetch(dataDir, webRoot, repoURL, branch)
+		result := Fetch(webRoot, repoURL, branch)
 		c <- result
 	}()
 	select {

src/main.go

@@ -1,18 +1,29 @@
 package main
 
 import (
+	"flag"
 	"log"
+	"net"
 	"net/http"
-	"os"
 )
 
-func main() {
-	dataDir := os.Args[1]
-	listenAddr := os.Args[2]
+var config Config
 
-	http.HandleFunc("/", Serve(dataDir))
-	err := http.ListenAndServe(listenAddr, nil)
+func main() {
+	configPath := flag.String("config", "config.toml", "path to configuration file")
+	flag.Parse()
+
+	if err := readConfig(*configPath, &config); err != nil {
+		log.Fatalln("failed to read configuration:", err)
+	}
+
+	listener, err := net.Listen(config.Listen.Protocol, config.Listen.Address)
 	if err != nil {
 		log.Fatalln("failed to listen:", err)
 	}
+
+	http.HandleFunc("/", Serve)
+	if err := http.Serve(listener, nil); err != nil {
+		log.Fatalln("failed to serve:", err)
+	}
 }

src/serve.go

@@ -19,7 +19,7 @@ import (
 
 const fetchTimeout = 30 * time.Second
 
-func getPage(dataDir string, w http.ResponseWriter, r *http.Request) error {
+func getPage(w http.ResponseWriter, r *http.Request) error {
 	host := getHost(r)
 
 	// if the first directory of the path exists under `www/$host`, use it as the root,
@@ -29,26 +29,26 @@ func getPage(dataDir string, w http.ResponseWriter, r *http.Request) error {
 	requestPath := path
 	if projectName, projectPath, found := strings.Cut(path, "/"); found {
 		projectRoot := filepath.Join("www", host, projectName)
-		if file, _ := securejoin.OpenInRoot(dataDir, projectRoot); file != nil {
+		if file, _ := securejoin.OpenInRoot(config.DataDir, projectRoot); file != nil {
 			file.Close()
 			wwwRoot, requestPath = projectRoot, projectPath
 		}
 	}
 
 	// try to serve `$root/$path` first
-	file, err := securejoin.OpenInRoot(dataDir, filepath.Join(wwwRoot, requestPath))
+	file, err := securejoin.OpenInRoot(config.DataDir, filepath.Join(wwwRoot, requestPath))
 	if err == nil {
 		// if it's a directory, serve `$root/$path/index.html`
 		stat, statErr := file.Stat()
 		if statErr == nil && stat.IsDir() {
 			defer file.Close()
-			file, err = securejoin.OpenInRoot(dataDir,
+			file, err = securejoin.OpenInRoot(config.DataDir,
 				filepath.Join(wwwRoot, requestPath, "index.html"))
 		}
 	}
 	// if whatever we were serving doesn't exist, try to serve `$root/404.html`
 	if errors.Is(err, os.ErrNotExist) {
-		file, _ = securejoin.OpenInRoot(dataDir, filepath.Join(wwwRoot, "404.html"))
+		file, _ = securejoin.OpenInRoot(config.DataDir, filepath.Join(wwwRoot, "404.html"))
 	}
 
 	// acquire read capability to the file being served (if possible)
@@ -103,7 +103,7 @@ func getProjectName(w http.ResponseWriter, r *http.Request) (string, error) {
 	}
 }
 
-func putPage(dataDir string, w http.ResponseWriter, r *http.Request) error {
+func putPage(w http.ResponseWriter, r *http.Request) error {
 	host := getHost(r)
 
 	err := authorize(w, r)
@@ -130,7 +130,7 @@ func putPage(dataDir string, w http.ResponseWriter, r *http.Request) error {
 		branch = "pages"
 	}
 
-	result := FetchWithTimeout(dataDir, webRoot, repoURL, branch, fetchTimeout)
+	result := FetchWithTimeout(webRoot, repoURL, branch, fetchTimeout)
 	if result.err == nil {
 		w.Header().Add("Content-Location", r.URL.String())
 	}
@@ -155,7 +155,7 @@ func putPage(dataDir string, w http.ResponseWriter, r *http.Request) error {
 	return result.err
 }
 
-func postPage(dataDir string, w http.ResponseWriter, r *http.Request) error {
+func postPage(w http.ResponseWriter, r *http.Request) error {
 	host := getHost(r)
 
 	err := authorize(w, r)
@@ -199,7 +199,7 @@ func postPage(dataDir string, w http.ResponseWriter, r *http.Request) error {
 	webRoot := fmt.Sprintf("%s/%s", host, projectName)
 	repoURL := event["repository"].(map[string]any)["clone_url"].(string)
 
-	result := FetchWithTimeout(dataDir, webRoot, repoURL, "pages", fetchTimeout)
+	result := FetchWithTimeout(webRoot, repoURL, "pages", fetchTimeout)
 	switch result.outcome {
 	case FetchError:
 		w.WriteHeader(http.StatusServiceUnavailable)
@@ -214,23 +214,21 @@ func postPage(dataDir string, w http.ResponseWriter, r *http.Request) error {
 	return result.err
 }
 
-func Serve(dataDir string) func(http.ResponseWriter, *http.Request) {
-	return func(w http.ResponseWriter, r *http.Request) {
-		log.Println("serve:", r.Method, r.Host, r.URL)
-		err := error(nil)
-		switch r.Method {
-		case http.MethodGet:
-			err = getPage(dataDir, w, r)
-		case http.MethodPut:
-			err = putPage(dataDir, w, r)
-		case http.MethodPost:
-			err = postPage(dataDir, w, r)
-		default:
-			http.Error(w, "method not allowed", http.StatusMethodNotAllowed)
-			err = fmt.Errorf("method %s not allowed", r.Method)
-		}
-		if err != nil {
-			log.Println("serve err:", err)
-		}
+func Serve(w http.ResponseWriter, r *http.Request) {
+	log.Println("serve:", r.Method, r.Host, r.URL)
+	err := error(nil)
+	switch r.Method {
+	case http.MethodGet:
+		err = getPage(w, r)
+	case http.MethodPut:
+		err = putPage(w, r)
+	case http.MethodPost:
+		err = postPage(w, r)
+	default:
+		http.Error(w, "method not allowed", http.StatusMethodNotAllowed)
+		err = fmt.Errorf("method %s not allowed", r.Method)
+	}
+	if err != nil {
+		log.Println("serve err:", err)
 	}
 }