1 files changed, 146 insertions, 0 deletions
diff --git a/main.go b/main.go
new file mode 100644
index 0000000..2b955fb
--- /dev/null
+++ b/main.go
@@ -0,0 +1,146 @@
+package main
+
+import (
+	"context"
+	"fmt"
+	"log"
+	"net"
+	"net/http"
+	"os"
+	"os/signal"
+	"os/user"
+	"path/filepath"
+	"strconv"
+	"sync"
+	"syscall"
+	"time"
+)
+
+func startServer(
+	s *Server,
+	listener net.Listener,
+	wg *sync.WaitGroup,
+	sigCtx context.Context,
+) {
+	defer wg.Done()
+
+	go func() {
+		err := s.Serve(listener)
+		if err != nil && err != http.ErrServerClosed {
+			log.Fatalf("Failed to start server (%s): %s", s.Label(), err)
+		}
+	}()
+
+	fmt.Printf("Started server (%s)\n", s.Label())
+
+	// Wait until we receive a signal to stop the server.
+	<-sigCtx.Done()
+
+	// Gracefully shutdown the server with timeout.
+	timeoutCtx, cancelTimeoutCtx := context.WithTimeout(context.Background(), time.Second*10)
+	defer cancelTimeoutCtx()
+	s.Shutdown(timeoutCtx)
+
+	fmt.Printf("Shutdown server (%s)\n", s.Label())
+}
+
+func downgradeToUser(uname string) error {
+	// Get gid and uid.
+	u, err := user.Lookup(uname)
+	if err != nil {
+		return err
+	}
+	// On POSIX system, gid and uid are integers.
+	gid, err := strconv.Atoi(u.Gid)
+	if err != nil {
+		return err
+	}
+	uid, err := strconv.Atoi(u.Uid)
+	if err != nil {
+		return err
+	}
+
+	// Set gid and uid.
+	err = syscall.Setgid(gid)
+	if err != nil {
+		return err
+	}
+	err = syscall.Setuid(uid)
+	if err != nil {
+		return err
+	}
+
+	return nil
+}
+
+func main() {
+	// Check mode
+	if len(os.Args) == 3 && os.Args[1] == "-check" {
+		configFileName := os.Args[2]
+		_, err := LoadConfig(configFileName)
+		if err != nil {
+			log.Fatalf("%s", err)
+		}
+		return
+	}
+
+	// Load config.
+	if len(os.Args) < 2 {
+		log.Fatalf("Usage: %s <config file>", os.Args[0])
+	}
+	configFileName := os.Args[1]
+	config, err := LoadConfig(configFileName)
+	if err != nil {
+		log.Fatalf("Failed to load configuration: %s", err)
+	}
+	configFileDir := filepath.Dir(configFileName)
+
+	// Set up listeners.
+	var listeners []net.Listener
+	for _, s := range config.Servers {
+		l, err := NewListener(&s)
+		if err != nil {
+			log.Fatalf("Failed to create listener (%s:%d): %s", s.Host, s.Port, err)
+		}
+		listeners = append(listeners, l)
+	}
+
+	// Set up servers.
+	var servers []*Server
+	for _, s := range config.Servers {
+		// Convert relative paths to absolute paths, based on config file location.
+		if s.ACMEChallenge != nil {
+			s.ACMEChallenge.Root = filepath.Join(configFileDir, s.ACMEChallenge.Root)
+		}
+		if s.TLSCertFile != "" {
+			s.TLSCertFile = filepath.Join(configFileDir, s.TLSCertFile)
+		}
+		if s.TLSKeyFile != "" {
+			s.TLSKeyFile = filepath.Join(configFileDir, s.TLSKeyFile)
+		}
+		servers = append(servers, NewServer(&s))
+	}
+
+	// Downgrade to non-root user.
+	if config.User != "" {
+		err := downgradeToUser(config.User)
+		if err != nil {
+			log.Fatalf("Failed to downgrade to user %s: %s", config.User, err)
+		}
+	}
+
+	// Catch signals to stop servers.
+	sigCtx, cancelSigCtx := signal.NotifyContext(
+		context.Background(),
+		syscall.SIGTERM, os.Interrupt, os.Kill,
+	)
+	defer cancelSigCtx()
+
+	// Start servers.
+	var wg sync.WaitGroup
+	for i, s := range servers {
+		wg.Add(1)
+		go startServer(s, listeners[i], &wg, sigCtx)
+	}
+	wg.Wait()
+}